Shaking Earth

Seismologists on trial in Italy

2011-05-25T18:03:00.000-04:00

Italian seismologists to be tried for manslaughter - May 25, 2011

Posted on behalf of Nicola Nosengo

Six Italian seismologists and one government official will be tried for the manslaughter of those who died in an earthquake that struck the city of L'Aquila on 6 April 2009.

The seven are accused of misinforming the population about seismic risk in the days before the earthquakes, indirectly causing the death of the citizens they had reassured.

If only they had used an underage prostitute, they probably would have been left alone.

The rapture that didn't happen did get me some blog hits

2011-05-22T22:30:00.001-04:00

I'll say one thing about the rapture that didn't happen: my blog entry about it got over 1,000 hits, and more comments than ever. Maybe there is something about the power of the right blog at the right time with the right title to get to people after all?

By the way, the "rapture day" of May 21 had the usual quakes, but nothing catastrophic. My son felt the 3.6 quake in the East Bay area.

In psychology class in 1970, I read When Prophecy Fails, by Leon Festinger et al., about what might happen to Harold Camping's band of followers. They'll conclude God gets it right, they got it wrong.

If the world ends on May 21, I can finally stop blogging

2011-05-18T07:40:00.000-04:00

I made a presentation about geophysics and the Japan earthquake to 7th graders at a local middle school last week. One student asked if I thought the world would end in 2012. My answer, not surprisingly, was no. Read NASA's response to that popular belief.

There have also been stories about the end of the world beginning with the rapture on May 21. That's in 3 days! This is supposed to be accompanied by huge earthquakes. One website states "On Saturday May 21st, the world will experience what Harold Camping has predicted a Global Earthquake to be the Greatest Earthquake ever. Camping’s Prophecy Predictions have been proven incorrect in the past, but he has learned from the mistake he made in 1994, and is confident about the date of May 21 2011. If the earth starts to shake on May 21 Doomsday, how will you react?"

Why would anyone believe this? I'd like to say the spiritual diversity of people is one of the things that makes our species beautiful, but I'm not sure I can.

Michael Welland on the geoblogosphere

2011-04-23T18:05:00.001-04:00

I came across this commentary from May of 2010 on the value of the "geoblogosphere." I thought I would pass it along, even though I didn't make Welland's list of blogs he reads. But he did lead to to a master list of geo blogs, and at least we're on that!

He is a recent convert to blog reading. He says:

.... but what’s the point? Why do these geologists write blogs and what is their value? A recent survey of the geoblogosphere conducted by Lutz Geissler of the Technical University Bergakademie in Freiberg, in collaboration with Robert Huber of the University of Bremen and Callan Bentley of Northern Virginia Community College, helps answer the first question and informs the second. The equally top-ranked responses to the question “why do you blog?” were “to inform”, “to share knowledge”, and “to popularise the geosciences” (followed closely by “to have fun”).

Combine this motivation and energy with the significant audience for many of these blogs, and there is arguably the prime value: knowledge-sharing and outreach...

What the majority have in common, however, is that they are current and immediate. Whether reporting on an ongoing research or fieldwork project, a volcanic or seismic event, providing links to newly published papers, or seeking ideas on the design of a new course, these blogs represent a unique means of rapidly disseminating – and accessing – information and ideas.

Listening (literally) to the Japanese earthquake

2011-04-21T09:16:00.000-04:00

NOAA has an audio of seismic waves generated by the Toholu earthquake. Seismic P-waves are, after all, esentially the same as sound waves.

Scientists at the NOAA Vents Program at Pacific Marine Environmental Laboratory and Oregon State University heard the March 11, 2011 Honshu, Japan earthquake using a hydrophone located near the Aleutian Islands of Alaska.

Tohoku quake and free oscillations

2011-04-18T22:58:00.000-04:00

Large earthquake cause the Earth to "ring like a bell," the phenomenon of free oscillations.

There are nice animations of the different toroidal and spheroidal modes of free oscillations at this web page from Lucien Saviot of the CNRS. Note the periods of the oscillations.

The image below shows the response of the superconducting gravimeter at Metsähovi, Finland. The gravimeter is also a long period seismometer. Time runs from the day of the quake on the left to five days later on the right. Hotter colors are higher amplitudes. The scale on the left gives the frequency of oscillation, where f=0.0006 cycles/second corresponds to a period of oscillation of 28 minutes.

Another reprsentation of some of the free oscillation data in the lower part of the frequency spectrum is shown below, from the same source.

The lowest mode is spheroidal mode 0S2 (54 minutes). All modes decay after a few days, except the lowest radial mode (0S0) which has an expected lifetime of 3-4 months. The radial oscillation mode changes radius of the Earth with the period of 20 minutes. The observed amplitude at Metsähovi is 0.06 mm on 17.3.2011.

Free oscillations of the Earth which had been theoretically predicted were first observed after the 1960 Chile quake, the largest earthquake ever recorded.

Google searches, blog hits

2011-04-10T09:32:00.000-04:00

Sometimes I wonder why and when I get hits for the blog. My colleague Teb recently showed me Google Trends, a neat tool that lets you look at trends in Google searches on one or more terms. The term "Japan earthquake brought up the following trend. The peak, of course, is when the Japanese earthquake occurred on March 11, with a decrease ever since.

Google Analytics also allows one to monitor the hist on one's own web site. Can't say I have mastered it yet (I don't find it too user friendly), but the graph below shows the hits on this blog, also since the Japan quake

Pretty good correlation. There are even corresponding upturns on March 14 and 28.

The hits have decreased, but I hope concern for the victims and the drive to improve earthquake protection everywhere will not.

Tsunamis and the height of the ocean column

2011-04-08T17:24:00.000-04:00

The National Data Buoy Center (sorry, no Gurl Center) of NOAA describes the Deep-ocean Assessment and Reporting of Tsunamis (DART) program. Each DART gauge is designed to detect and report tsunamis, by looking at the pressure of the disturred column of ocean water.

Maps are available here to show the location of these sensors, such as the map below for the eastern side of Japan.

The image below shows the vauation in ocean height for the 24 hours and the 4 minutes surrounding the earthquake. Note the red onset of the higher frequency changes in ocean thickness on March 11 - that's the origin of the tsunami. It is soon followed by the maximum change of 1 meter, relatively small in the open ocean compared to the wave buildup when it approaches the shore.

For comparison sake, a normal period of four days showing diurnal tidal fluctuations with amplitudes of 0.5 meters looks like this:

Tidal gage data re-visited - tsunami wave spectra vs. distance

2011-04-07T18:10:00.001-04:00

After the last post, I was thinking about that dominant 20-30 minute periodicity in the tidal gage responses to the tsunami waves on the west coast of the U.S., reflecting the time difference between tsunami peaks. That is one of the classic hazards with tsunamis: the wave trough may come in first, causing a beach to be emptied of water, and then when people walk out further away from shore to explore, the peak arrives half a period of time later, and people are trapped.

My visual memory of the tide gage data from the Japanese coast showed just an initial impulse. But when I looked at it again (see below, a blow-up from the last blog), one can see the initial impulse at about 30 minutes after the quake, and then a series of peaks for another 1-2 hours, at intervals of about 3-4 minutes.

Higher frequencies are attenuated more quickly with distance, as also happens for the spectral content in seismic surface waves, so by the time the waves reach the U.S. west coast, lower frequencies dominate.

Japan tsunami as recorded on tidal gages

2011-04-06T20:36:00.000-04:00

The NOAA Center for Tsunami Research provides data from sea-level tidal gages in the Pacific and along the U.S. coastline. The figure below compares data (in black) with DART (Deep-ocean Assessment and Reporting of Tsunamis) model series (red). The Tokyo record below shows a maximum peak-to-peak amplitude of over 2 meters.

Data are available for several area:

Data from the U.S West Coast, shown below, reveals an approximately 30 minute periodicity of the tsunamigenic tidal variation. Also note the 3-meter high amplitude variation at Crescent City, a location notorious for its large tsunami waves.

More information on tsunami wave heights along the Japanese coast

2011-04-05T09:20:00.002-04:00

Information from NOAA (National Oceanographic and Atmospheric Administration) on the maximum tsunami heights along the Japanese coast is a bit more subdued than the information I listed in the last post:

MARCH 11, 2011 EYEWITNESS AND INSTRUMENTAL RECORDINGS
The highest wave from the March 11, 2011 tsunami was 13 meters reported by an eyewitness at Minami Sanriku town. Tide gauge recordings in Japan range from 1 to 7 meters. Three meter waves were observed by eyewitnesses in the Kuril Islands, Russia. Two meter waves were observed at tide gauges in South America, Hawaii, and the west coast of the United States. The highest wave ever recorded by an ocean-bottom sensor was measured at 1.08 meters by DART® station 21418 located 450 nautical miles northeast of Tokyo. NGDC [National Geophysical Data Center] will continue to update the historic tsunami database as eyewitness and field survey reports are received.

The map below shows the near-field effects of the event including deaths, missing, maximum wave heights and arrival times at tide gauges, water heights from field surveys (data current as of March 28, 2011, will be updated weekly).

Source: NGDC/NOAA. Click to enlarge

One large quake does not deserve another (at least not far away)

2011-04-04T21:19:00.001-04:00

The Seismological Society of America has a surprisingly active Facebook page, with several posts a day.

One referred to a recent scientific article and WSJ recap on whether large, distant earthquakes were related causally and temporally. A student had in fact recently asked me whether she should study in Berkeley this summer in the wake of the Japan earthquake. The Nature Geoscience paper, Absence of remotely triggered large earthquakes beyond the mainshock region, by Tom Parsons Aaron A. Velasco, concluded that "the regional hazard of larger earthquakes is increased after a mainshock, but the global hazard is not."

This paper and related research were summarized in the Wall Street Journal, by Gautam Naik.

From Wall Street Journal

Tsumami heights in Japan

2011-04-04T13:28:00.001-04:00

I finally found the graph I have been looking for, showing tsunami heights in Japan. These data from a preliminary report comes from yet another clearinghouse type site for tsunami data and information, the Coastal Engineering Committee of the Japan Society of Civil Engineers. The geographic location of the individual data points are not indicated, other than distance from tsunami "ground zero." Regular tidal fluctuations have not been removed. There is a lot of scatter and very high values at a distance of 0 km. The highest height shown is 30 meters (100 feet!), and there are consistent heights of over 15 meters (50 feet).

Click on the image for a more readable version.

Before and after photos of the Tohoku tsunami

2011-04-03T18:38:00.001-04:00

ABC (Australian Broadcasting Corporation) has some impressive before and after photograph pairs of the tsunami damage in the Sendai region of Japan.

Japan tsunami animation - wave interference

2011-03-30T10:39:00.002-04:00

This NOAA animation of the calculated tsunami is quite impressive:

Listen to the accompanying mini-lecture. The resulting wave patterns due to bathymetry, wave reflection and refraction are visually stunning.

This is just a computer prediction of the expected tsunami. We'll take a look at tsunami data soon.

Tohoku earthquake - the tsunami

2011-03-29T09:32:00.000-04:00

Finally, I am getting to the tsunami.

I'll be presenting some of the images that I find most impressive, although not too much in the way of photos or videos.

The figure above shows the maximum tsunami amplitudes forecast (i.e., predicted, not observed) by the NOAA (National Oceanographic and Atmospheric Administration) Center for Tsunami Research using the MOST (method of splitting tsunamis) model.

The scale saturates in Japan (I'll look for a higher resolution image for the near epicenter effects), is about 0.5 meters in Hawaii. 0.25 meters on the west coast of the U.S., and about 0.1 meters on the west coast of South America.

Seismic spectra and building response

2011-03-26T19:47:00.002-04:00

Seismic waves can be analyzed for their characteristic periodicities. Longer period components will have more effect on taller buildings, while shorter periodicities will have greater impact on shorter buildings. This phenomenon was recognized in the 1986 Mexico earthquake. This phenomenon is nicely explained in a web page from MCEER, the Multidisciplinary Center for Earthquake Engineering.

There are some interesting links to Japanese data on the Tohoku earthquake from Tolyo University. One is:

The comparison of long-period ground motion: The feature of seismic ground motion in city center and influence by architectural structure (By:Dr.Furumura and Dr.Takemura)

A velocity response spectrum is calculated according to waveform recorded at Earthquake Research Institute in Bunkyou-ku district. The figure shows comparison with that of Niigata Chuetsu earthquake in 2004. The Chuetsu earthquake had strong long-period ground motion with period of 7 second, which causes only a minor damage mainly among skyscraper buildings. The 2011 Tohoku earthquake has about the same strength of velocity response occurred in a wide periodic band from 0.5 to 20 second. Not only skyscrapers but also all kind of buildings from wooden building (below 0.5 second) to a low-slung building (around 1second) and skyscraper buildings (few second).

Groundshaking damage to buildings, Japan

2011-03-25T16:56:00.001-04:00

So much of the damage done after the Tohoku quake resulted from the tsunami, but there was also damage of buildings due to the groundshaking in high areas that were not damaged by the tsunami. Some reports and images can be found at the Earthquake Engineering Research Institute web site.

A number of field reports on damage done in the epicentral area are given here.

A report by Shunzuke Otani on Building Damage in Sendai says:

"Miki Shoji Co, a commercial business company, reported building damage statistics by external observation along the Sendai main street; out of 175 buildings
          No damage: 95
          Some damage, but could be operational in short time: 66
          Severe damage, need some time before use: 14
          Collapse or tilting: 0
Sendai is the largest city in the affected area. A church in Mito City, Ibaragi Prefecture, suffered severe damage in the tower. A automobile ramp to the roof parking area collapse and killed three persons in automobiles; the ramp is supported by steel columns and connected to the main structure of a super market building." Images of these are shown below.

Sendai church damage

Sendai parking garage damage

Mercalli intensities for the Tohoku earthquake

2011-03-22T09:16:00.003-04:00

RMS is a provider of products, services, and expertise for the quantification and management of catastrophe risk. Below is a Mercalli intensity map produced by RMS for the Tohuku earthquake.

The Mercalli intensity map indicates damages to structures and human reactions to the event. Mercalli intensities tend to be highest near the epicenter, and decrease with distance.

[I mis-read my colors, so this paragraph is not true: In this case, the highest intensities of VI are not at the epicenter. This is presumably because of regional geology; unconsolidated rocks amplify the groundshaking, so the intensity pattern depends in part on the geology of the region.]

The Mercalli scale is described by the USGS. The description for Mercalli intensity VI is:

V. Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable objects overturned.

VI. Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight.

VII. Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken.VIII. Damage slight in specially designed structures; considerable damage in ordinary substantial buildings with partial collapse. Damage great in poorly built structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned.

Because of the earthquake-resistant building construction in Japan, the groundshaking of the quake did not do much damage. The tsunami was to blame for most of the destruction.

How much did the rest of Japan move?

2011-03-21T20:06:00.000-04:00

This map from JPL and NASA based on gps measurements shows movements up to 5 meters (about 15 feet) on the mainland itself.

Ground acceleration for the Tohoku quake

2011-03-21T11:37:00.003-04:00

Tohoku, by the way, is Japanese for northeast, since that is the part of the island of Honshu where the earthquake occurred. It is also being referred to as the Sendai earthquake, Sendai being the largest big city nearby.

The primary hazard intrinsically associated with earthquakes is groundshaking. When the elastic energy stored in the crust is released by the earthquake and motion on the fault, the stored energy causes the ground to vibrate, or accelerate back and forth. The figure below from the USGS shows the peak acceleration in the vicinity of the quake caused by the shaking earth.

The peak ground acceleration in the graph below was almost three times the Earth's gravitational acceleration (g).

By default, buildings are designed to withstand the vertical acceleration due to gravity, but not necessarily to withstand horizontal ground accelerations of the same magnitude. This is why earthquake-resistant buildings must be designed to deal with. Japan has done a good job with this, so the major damage in the quake was not caused by the groundshaking.

Fault movement for the Tohoku Japan earthquake

2011-03-20T12:50:00.001-04:00

At times after major disasters, there is so much information, but so spread out. Harvard has set up the Japan Sendai Earthquake Portal for data sharing and exchange, with links to other relevant sites. That portal led me to the figure below.

The figure below, from Penn State, shows co-seismic slip - movement on the fault itself. The red dots are actually locations of the main earthquake and aftershocks.

From the figure caption: A preliminary comparison of an estimate of coseismic slip (created in collaboration with Thorne Lay at UC Santa Cruz and Hiroo Kanamori at CalTech) with the aftershocks and bathymetry. The rainbow-filled circles show the slip pattern for the Mw 9.0 earthquake. The deeper red circles are the aftershock locations.

Credit: Rupture model by C. J. Ammon, Penn State, T. Lay, UC Santa Cruz, and H. Kanamori, Caltech. Aftershock data from the US Geological Survey.

Thrust faulting for the Japan earthquake

2011-03-17T15:47:00.001-04:00

The images below are taking from a USGS poster on the Japanese earthquake.

As in the last post, the balloon diagrams are "fault plane solutions." These are based on the P-waves arriving at different seismic stations, and whether the first pulse of energy is a compression or a dilatation (stretching apart). These patterns reveal the orientation of the fault on which the earthquake occurs, and the nature of the faulting. Note that in the top figure, the boundary between the black and white portions of the balloon diagrams are parallel to the major plate boundary between the Pacific plate (to the east) and the Eurasian pate (to the west). This tells us what the strike of the fault is. Also, the pattern of black (compressions) and white (dilatations) shown corresponds to a thrust fault occurring on a fault plane shallowly dipping to the northwest, as suggested by the pattern of earthquake locations shown on the second diagram. Thus, we can use seismic waves to tell us what kind of faulting of the Earth's crust occurred 25 km below the surface, even though no one is there to directly observe it.

Slip of almost 50 meters for Japan quake

2011-03-17T08:16:00.000-04:00

The figure below from the University of California at Santa Barbara shows a maximum slip of almost 50 meters (165 feet) on the fault accompanying the Japan earthquake. The star shows the epicenter of the main shock. Red dots are the aftershocks (M>3). The black line indicates the major plate boundary

Oher interesting resources for this event, some of which I will return to, are referred to from the IRIS web page.

Animation of Japan foreshocks-main shock-aftershocks

2011-03-16T18:57:00.003-04:00

This animation from YouTube showns the main shock at 1:16, with both preceding foreshocks and succeeding aftershocks. Because the energy release increases by a factor of 27.5 with each step in magnitude, most of the energy is released by the main shock.

Beware if you are in the library: music is included.

You can get a sense of all that activity by looking at the lists at the USGS/NEIC website.

Japan quake was magnitude 8.9, is now 9.0

2011-03-16T13:55:00.000-04:00

"The USGS has updated the magnitude of the March 11, 2011, Tohoku earthquake in northern Honshu, Japan, to 9.0 from the previous estimate of 8.9. Independently, Japanese seismologists have also updated their estimate of the earthquake’s magnitude to 9.0. This magnitude places the earthquake as the fourth largest in the world since 1900 and the largest in Japan since modern instrumental recordings began 130 years ago.

"The USGS often updates an earthquake’s magnitude following the event. Updates occur as more data become available and more time-intensive analysis is performed. There are many methods of calculating the energy release and magnitude of an earthquake. Some methods give approximate values within minutes of the earthquake, and others require more complete data sets and extensive analysis. Due to inherent uncertainties in the modeling of energy and magnitude, the results from different agencies often vary slightly. These magnitude discrepancies arise from the use of different data and techniques. For more information on why magnitudes change, see the Earthquake Hazards Program FAQ website."

Largest earthquakes in history

2011-03-15T21:54:00.009-04:00

By magnitude (Japan quake comes in as #4)

Event	Date/time	Lat	Long	Mag	Fatalities	Region
1.	1960-05-22 19:11	-38.29	-73.05	9.5	1,655	Chile
2.	1964-03-28 03:36	61.02	-147.65	9.2	125	Prince William Sound, Alaska
3.	2004-12-26 00:58	3.295	95.982	9.1	227,898	off the west coast of northern Sumatra
4.	2011-03-11 05:46:23	38.322	142.369	9.0		Near the East Coast of Honshu, Japan
5.	1952-11-04 16:58	52.76	160.06	9.0		Kamchatka, Russia
6.	2010-02-27 06:34:14	-35.846	-72.719	8.8		Offshore Maule, Chile
7.	1906-01-31 15:36	1.0	-81.5	8.8	1,000	Colombia-Ecuador
8.	1965-02-04 05:01	51.21	-178.50	8.7		Rat Islands, Alaska
9.	2005-03-28 16:09	2.074	97.013	8.6	1,313	Northern Sumatra, Indonesia

By casualties (Japan will not make this somewhat subjective list):

Rank	Death toll	Event	Location	Year
1.	&0000000000830000000000830,000	1556 Shaanxi earthquake	China	01556-01-21556
2.	&0000000000242419000000242,419–779,000	1976 Tangshan earthquake	China	01976-07-281976
3.	&0000000000316000000000316,000+	2010 Haiti earthquake	Haiti	02010-01-122010
4.	&0000000000250000000000250,000	526 Antioch earthquake	Antioch, Byzantine Empire (now Turkey)	00526-526
5.	&0000000000235502000000235,502	1920 Haiyuan earthquake	China	01920-12-11920
6.	&0000000000230210000000230,210	2004 Indonesian earthquake	Indonesia	02004-12-262004
7.	&0000000000230000000000230,000	1138 Aleppo earthquake	Syria	01138-1138
8.	&0000000000200000000000200,000	856 Damghan earthquake	Iran	00856-12-2 856
9.	&0000000000150000000000150,000	893 Ardabil earthquake	Iran	00893-03-2893
10.	&0000000000142000000000142,000	1923 Great Kanto earthquake	Japan	01923-09-1923
11.	&0000000000137000000000137,000	1730 Hokkaido earthquake	Japan	0171730
12.	&0000000000123000000000123,000	1908 Messina earthquake	Italy	01908-12-21908
13.	&0000000000110000000000110,000	1948 Ashgabat earthquake	Turkmen SSR, Soviet Union (now Turkmenistan)	01948-10-01948
14.	&0000000000100000000000100,000	1290 Chihli earthquake	China	01290-09-21290
15.	&0000000000100000000000100,000	1755 Lisbon earthquake	Portugal	01755-11-011755
16.	&0000000000100000000000100,000	1667 Shamakhi earthquake	Azerbaijan	01667-11 1667

Or see the USGS list.

Japan quake, some of the early news

2011-03-15T18:19:00.000-04:00

Here were some of the early news stories that impressed my geophysics students Peter Rippberger, Hannah Rosenberg, and Matt Slowinksi:

http://www.bbc.co.uk/news/world-middle-east-12307698
Up to date coverage of the diasster in Japan from BBC news report.

http://www.npr.org/?refresh=true
One of the worst effects of earthquakes are the tsunamis caused by the quake, check out the link to learn more.

http://www.affordablecebu.com/load/news/japan_earthquake_and_tsunami_pictures_march_11_2011/37-1-0-663
Look at the link to see pictures from the devastating event.

http://www.youtube.com/watch?v=DePXcKeaHZ4&amp
Look at this live footage of how quickly the flood spreads.

http://www.youtube.com/watch?v=j3fUqdGXLbM&playnext=1&list=PL0870831CE43351E1
Here is a video from one of the residents of Japan while the Earthquake was occuring.

Japan earthquake - seismograms

2011-03-14T20:57:00.005-04:00

My geophysics students Eamon Hall, Conor Neal, and Stacey Sosenko tracked down this seismogram from the Australian seismograph network:

Seismograms from the western Australia network of seismograms shows the initial pulse a little more than 10 minutes after the main quake, as shown in the figure below.

The Franklin & Marshall seismograph is located about 93 degrees away from the focus and felt the quake about 13 minutes after it struck, as expected. The seismogram also shows up two aftershocks later in the day.

Or, check out some more seismograms using the Rapid Earthquake Viewer.

Japan 8.9 quake - the source

2011-03-14T16:21:00.002-04:00

On Friday, the morning after the devastating earthquake in Japan, I had my geophysics students compile some information about the quake.

Elvis Andino, Stephanie Douglas, and Andrew Tsang looked at the source parameter. They found:

The epicenter occurred at 38.322°N, 142.369°E on the Japan Trench subduction zone, where the Pacific plate is subducting beneath the Eurasian plate. The epicenter was 373 km NE of Tokyo. The earthquake focus was about 24 km below the sea floor.

As shown below in the fault plane solution, the earthquake exhibited thrust faulting, consistent with its location along a subduction zone. The NE-SW strike of the fault plane is parallel with the orientation of the plate boundary shown above.

It had a magnitude of 8.9, putting it 5th on the USGS's list of largest earthquakes since 1900, right before the 2010 Chile earthquake,

Large foreshocks preceded the main shock over the previous two days, including a M7.2 quake about 40 km from the epicenter of the big earthquake.

Because Japan is partially surrounded by fault zones, it has had many earthquakes in its history. These have mostly been shallow quakes. The last major earthquake on the same fault was in 2005, a M7.0

Arkansas 4.7 quake, 2/28/11

2011-03-07T07:35:00.000-05:00

A magnitude 4.7 earthquake happened in Arkansas on Feb. 28. It's interesting that the Arkansas Geological Survey has some decent web pages on earthquakes in the New Madrid Seismic Zone, but I couldn't find anything yet on this particular event.

According to the USGS:

This figure [below] shows the distribution of earthquakes in north-central Arkansas that have occurred since June 2010. Earthquakes on the figure are color-coded, with red circles denoting earthquakes that occurred from June 4th, 2010 to February 14, 2011, and orange circles denoting earthquakes that occurred from February 15, 2011 to March 1, 2011. The space-time pattern shows a systematic shift in seismicity to the southwest starting on February 15, 2011. White triangles show the location of real-time seismic stations in the vicinity of the earthquake swarm that are used by the University of Memphis and USGS in their complimentary monitoring activities.

NZ aftershock was more damaging than main shock

2011-02-26T20:11:00.002-05:00

When it comes to earthquake damages, magnitude is not everything.

The February 22, 2011, 6.3-magnitude earthquake that struck the South Island of New Zealand was less powerful than the September 3, 2010, 7.1 quake that struck to the west of Christchurch. Black circles on the diagram below from NASA (the source of this information) represent earthquakes in the region between these dates. Red circles show the locations of the magnitude 6.3 quake and aftershocks on February 22 and the morning of February 23. Larger circles represent stronger earthquakes. Yellow shows urban areas, including Christchurch.

In fact, the USGS characterized the February 22 event as an aftershock of the quake on September 3.

The Darfield earthquake in September 2010 caused no casualties, even though it had a higher magnitude. Besides striking closer to a major population center, the 6.3-magnitude Christchurch earthquake had a depth of just 5 kilometers (3 miles). The New Zealand Herald reported that, whereas the Darfield quake happened in the early morning hours, the February 22 quake struck at the “worst possible time” of day—at the lunch hour when city streets were crowded with shoppers, diners, office workers, and school children. Moreover, some of the buildings that collapsed may have been weakened by the September 2010 quake.

Seismogram on New Zealand earthquake

2011-02-22T08:07:00.002-05:00

I have been learning to use the software and database Global Earthquake Explorer for my geophysics course this semester. It seems very useful, although I am still trying to figure out how I can recover ground motion amplitudes in order to have my students calculate magnitudes.

Below is the seismogram from the Christchurch, New Zealand, earthquake, as recorded by the seismograph at South Karori, New Zealand, and retrieved using GEE.

Conflicing research on state of stress in Chile

2011-02-08T13:27:00.003-05:00

The New York Times carries an article today about the state of stress in the vicinity of the epicenter of last February's magnitude 8.8 Chile earthquake. Different sources of information - seismic waves, gps, tsunami waves - have yielded somewhat different pictures. The epicenter occurred outside of the 200-mile-long Darwin gap which had not seen a large quake since one that Charles Darwin observed in 1835. Did the occurrence of the 2010 quake lead to a stress increase in this gap, and a higher risk of an upcoming large quake? We have the usual conclusion: more data are needed.

200th anniversary of the New Madrid earthquakes

2011-02-04T17:42:00.000-05:00

From the New Madrid bicentennial site:

"Several of the largest historical earthquakes to strike the continental United States occurred in the winter of 1811-1812 along the New Madrid Seismic Zone, which stretches from just west of Memphis, Tennessee into southern Illinois. These earthquakes produced at least three temblors between magnitude 7-8, and hundreds of aftershocks.

"In 2011 and 2012, there will be events held throughout the central United States observing the 200th Anniversary of the great 1811 and 1812 New Madrid earthquakes that forever changed the mid-western landscape. These quakes were felt across the U.S. and as far south as the Gulf of Mexico, and as far north as Canada. Organizations from across the United States will participate in the bicentennial events, which range from conferences, workshops, public outreach events, multi-state earthquake exercises, field trips, and more. Organizers of the New Madrid Bicentennial events (NMB) are already planning the following activities:

Bicentennial Kickoff - February 11, 2011
Earthquake Awareness Month - February 2011
Seismological Society of America Meeting - April 2011
Great Central U.S. ShakeOut - April 28, 2011 @ 10:15a.m.
National Level Exercise (NLE2011) - May 16-20, 2011
Earthquake Awareness Month - February 2012
National Earthquake Conference - April 2012
EERI Annual Conference - April 2012
St. Jude Dream Home Partnership - April 2012"

LiDar, faults, and earthquake studies

2011-01-30T16:31:00.001-05:00

I recently came across another regional earthquake-related blog that was new to me. Groundswell was created to increase awareness and spread information about seismicity, earthquake research and mitigation efforts in the southwestern US.

Groundswell had a post about LiDar and fault studies. LiDar - light detection and ranging - is a very precise way of obtaining digital elevation models from aircraft using laser beams reflected from the Earth's surface.

Groundswell linked to a video from the website OpenTopgraphy, "A Portal to High-Resolution Topography Data and Tools," an NSF supported facility based at the University of California, San Diego.

Here is that video:

Earthquake Report web site

2011-01-23T22:01:00.001-05:00

I came across an eartquake site named Earthquake Report.

It looks like a well designed website which contains information on recent and significant earthquakes.

It says about itself:

Earthquake Report has been created by Armand Vervaeck from Belgium (at right).

Earthquake Report has only 1 goal : reporting about earthquakes the best possible way.

Earthquake Report tries to bridge the gap in between science and basic understanding.

News in this site will not only appear very quickly, but we always try to bring Added Value news you won't find anywhere else.

Those looking only for scientific facts should use the USGS, EMSC and other governmental organizations.

Earthquake Report focuses on the Impact of Earthquakes on people. We will search for unique news, even in the most remote places on Earth. Victims of an Earthquake in the jungle of Papua New Guinea merit the same attention as those people living in Port au Prince or Conception.

It seems to have educational and outreach goals consisten with those of this site, but with an explicitly global emphasis.

Go have a look, and bookmark it if you like it. Nice work, Armand,

PBS falls short on the Haiti earthquake anniversary

2011-01-17T22:31:00.001-05:00

Two of my favorite PBS programs had shows about Haiti one year after the disastrous earthquake.

I found both of them to be wanting.

The Frontline program Battle for Haiti spent the whole hour discussing criminals and gang members who escaped from prison at the time of the quake, and have since come to rule and terrorize neighborhoods and tent villages. I don't doubt that this is a serious problem, but I had a hard time believing that this was the only issue that should be focused on in discussing the country's recovery efforts. It seemed a somewhat Willy Horton-ish portrayal of an entire country. But you can stream the program using the link above, and judge for yourself.

The Nova program - Deadliest Earthquakes - was about the science of large quakes, such as those that occurred in Haiti and Chile during 2010. This is basically a re-hash of the type of the type of earthquake program Nova does about once a decade, reporting on a recent disastrous earthquake that heroic scientists (working "around the clock" to stave off future disasters), and the hope for a way to predict future quakes. After the usual skepticism about quake predictability (which is well justified by the history of that effort), a new possible magic bullet for prediction - the slow quake - is offered up. I watched this film with the thought of showing it in my geophysics course this semester, and I probably will, but the visualizations of plate movements, fault motions, and seismic waves are awful and inscrutable. The old fashioned cartoon style animations were great, but now we have nondescript and indecipherable wire mesh visuals which hardly show anything, in my opinion. But again, you can stream the show and judge for yourself.

If you'd like to see a fascinating PBS program that deals with the intersection of science, ambition, and public policy, look for Dinosaur Wars, the American Experience show about the epic slugfest between dinsoaur hunters OC Marsh and Edward Drinker Cope during the latter half of the 19th century.

Earthquakes in review for 2010 - USGS

2011-01-11T14:34:00.001-05:00

From a press release by the U.S. Geological Survey:

While the U.S. Geological Survey recorded 22 magnitude-7 or larger earthquakes in 2010, almost all the fatalities were produced by one — the major quake that hit Haiti on Jan. 12.

In 2010, about 227,000 people were killed due to earthquakes, with over 222,570 from the magnitude-7.0 Haiti event, as reported by the United Nations Office for Coordination of Humanitarian Affairs.

According to official estimates, the Jan. 12 earthquake in Haiti injured 300,000 people, displaced 1.3 million, and left 97,294 houses destroyed and 188,383 damaged in Port-au-Prince and much of southern Haiti. In Haiti, this high-intensity shaking together with both buildings vulnerable to earthquakes and high population exposure resulted in catastrophe.

A magnitude-8.8 earthquake that hit offshore Bio-Bio, Chile, on Feb. 27 was the largest recorded in 2010. It killed at least 577 people, with about half of those deaths caused by an earthquake-generated tsunami. While the energy released by this earthquake was more than 500 times that of the one that struck Haiti, the fatalities were far fewer due to strict building codes in Chile and lower maximum shaking intensities.

As usual, the biggest earthquake in the United States in 2010 was in Alaska’s Aleutian Islands. This year it was a magnitude-6.6 event on July 18 in the Fox Islands, and it caused no damage or casualties. The biggest 2010 earthquake in the contiguous United States was a magnitude 6.5 that shook Northern California on Jan. 10. About 30 people were injured and moderate damage occurred to hundreds of homes and buildings in the Eureka-Ferndale area. The event was felt as far away as Portland, Ore. A series of minor earthquakes peppered Oklahoma throughout the year, including a magnitude 4.4 on Oct. 13 that injured two people in Norman.

An unusual earthquake occurred near the edge of the Continental Shelf about 125 km south-southeast of Westhampton, Long Island, New York, on Nov. 30. Because it was offshore, the magnitude-3.9 tremor caused no damage, but it was felt throughout Long Island, in large parts of Connecticut and New Jersey, and as far away as Maine and West Virginia.

A magnitude-2.1 earthquake in New Jersey on Christmas Day and a magnitude-3.4 in Washington, DC, on July 16 round out the more unique seismic events recorded. The latter shook the windows in the White House, and the USGS received over 21,724 reports on the Did You Feel It? website.

A complete list of 2010 earthquake statistics can be found on the Earthquake Information for 2010 website.

From USGS:

I think I see plate tectonics!

Haiti, one year later

2011-01-10T17:57:00.000-05:00

Along with other major media outlets, National Public Radio has a story on Haiti, one year after its disastrous earthquake. You may read or listen to the story.

The New York Times offers a series of images before and after the earthquake.

Despite much aid. there is often a mismatch between what is offered and what is needed, and insufficient coordination between different agencies.

Seismologist Jack Oliver

2011-01-08T16:14:00.001-05:00

Jack Oliver, co-author of one of the seminal papers about plate tectonics and seismology, has passed away.

From the LDEO website, where you can read the full obituary:

Dr. John Ertle “Jack” Oliver, a geophysicist with roots at Lamont-Doherty Earth Observatory whose research helped revolutionize our understanding of the basic forces shaping the planet, died peacefully at his home in Ithaca, N.Y., on Wednesday, Jan. 5, 2011. He was 87.
He was a former chair of the Department of Geology at Columbia University and head of the seismology program at Lamont from 1955-71.
Together with fellow Lamonters Bryan Isacks and Lynn Sykes, he wrote a paper in 1968, “Seismology and the new Global Tectonics,” which made a compelling geophysical case for the then-novel theory of plate tectonics, a theory that now forms the basis for all our current understanding of how the Earth works.
“It was literally the bible for understanding seismology,” said Larry D. Brown, a former student of Oliver’s who is now chairman of Cornell’s Department of Earth and Atmospheric Sciences. “It was one of the top five seminal papers on plate tectonics.”
“Jack Oliver, along with Bryan Isacks, Lynn Sykes, and others in the Lamont seismology group, showed how the properties of earthquakes were a near-perfect fit to the emerging theory of plate tectonics,” said Arthur L. Lerner-Lam, associate director of the seismology division at Lamont. “Their work was key in convincing scientists of the explanatory power of the ‘new global tectonics,’ and opened up new areas of research that even today remain fundamental.”

A pdf file of the Isacks, Oliver and Sykes paper can be downloaded here. I still use it in my teaching of geophysics because of the clear and illustrative examples.

Insurance Company Munich Re - Natural Catastrophes in 2010

2011-01-04T15:16:00.001-05:00

Insurance companies oviously care about natural catastrophes and the resulting damages. I walked by Munich Re most days on my way to the office when I had my Spring semester sabbatical last year. The Walking Man sculpture stands out front of Munich Re - see my photo below.

Munich Re has issued a press release on natural catastrophes of 2010. Read the full press release at the Munich Re webpage.

Several major catastrophes in 2010 resulted in substantial losses and an exceptionally high number of fatalities. The overall picture last year was dominated by an accumulation of severe earthquakes to an extent seldom experienced in recent decades. The high number of weather-related natural catastrophes and record temperatures both globally and in different regions of the world provide further indications of advancing climate change.

Altogether, a total of 950 natural catastrophes were recorded last year, nine-tenths of which were weather-related events like storms and floods. This total makes 2010 the year with the second-highest number of natural catastrophes since 1980, markedly exceeding the annual average for the last ten years (785 events per year). The overall losses amounted to around US$ 130bn, of which approximately US$ 37bn was insured. This puts 2010 among the six most loss-intensive years for the insurance industry since 1980. The level of overall losses was slightly above the high average of the past ten years.

"2010 showed the major risks we have to cope with. There were a number of severe earthquakes. The hurricane season was also eventful – it was just fortunate that the tracks of most of the storms remained over the open sea. But things could have turned out very differently", said Torsten Jeworrek, Munich Re's Reinsurance CEO. "The severe earthquakes and the hurricane season with so many storms demonstrate once again that there must be no slackening of our efforts to analyse these risks in detail and provide the necessary insurance covers at adequate prices. These prices calculated by the insurance industry make it possible to assess the economic consequences of these otherwise difficult-to-evaluate risks."
Major catastrophes dominate the list of losses
In all, there were five catastrophes last year assignable to the top category of "great natural catastrophes" based on the definition criteria of the United Nations: the earthquakes in Haiti (12 January), Chile (27 February) and central China (13 April), the heatwave in Russia (July to September), and the floods in Pakistan (also July to September). These accounted for the major share of fatalities in 2010 (around 295,000) and just under half the overall losses caused by natural catastrophes.

One of the most devastating earthquakes in the history of the past 100 years, the quake in Haiti on 12 January killed more than 220,000 people. Only the 1976 Tangshan earthquake in China claimed more lives (242,000). Whilst the earthquake in Haiti resulted in human tragedy on a staggering scale, it gave rise to only negligible losses for the insurance industry, as is so often the case in developing countries.

Five-hundred times more energy than in the Haiti quake was released by the earthquake that hit Chile just over a month later. With overall losses of US$ 30bn and insured losses of US$ 8bn, this quake was last year's most expensive natural catastrophe. Chile is a highly developed country with very strict building codes to take account of the high earthquake exposure. As a result, there were comparatively few human casualties, despite the severity of the quake – the fifth-strongest ever measured – although people were killed in Chile, too.
Asia and America most frequently affected by catastrophes
Natural catastrophes in Australia/Oceania gave rise to around 16% of global losses. The costliest event was the earthquake which occurred on 4 September in Christchurch, the third-largest city in New Zealand. Overall and insured losses were in the billions here as well. In Australia, there were two severe hailstorm losses, each of which caused overall losses of well over US$ 1bn in March.

National Earthquakes Hazard Reduction Program

2011-01-03T16:07:00.000-05:00

The National Earthquake Hazards Reduction Program (NEHRP) is a multiagency program established by Congress “to reduce the risks of life and property from future earthquakes in the United States.” The four federal agencies participating in NEHRP are the Federal Emergency Management Agency (FEMA), the National Institute of Standards and Technology (NIST), the National Science Foundation (NSF),
and the U.S. Geological Survey (USGS). NIST serves as the lead agency for NEHRP.

NEHRP was initially authorized by Congress in 1978 and has been subsequently reauthorized at 2- to 5-year intervals. The latest reauthorization of NEHRP (Public Law 108–360) authorized funding through fiscal year (FY) 2009. This legislation also required that the NEHRP Interagency Coordinating Committee (ICC), which directs the program, submit an annual report on NEHRP budgets and activities. The ICC submits this annual report in accordance with Section 103(1) of Public Law 108–360.

Many related links, including the latest annual report, can be found on the web page linked to above.

Seismological Society of America meeting, 2011

2011-01-02T21:26:00.000-05:00

SSA 2011
April 13-15, 2011

Memphis, Tennessee

SSA’s 2011 Annual Meeting will provide a stimulating exchange of research on a wide range of topics with colleagues from all over the world. Oral presentations, poster sessions, exhibits, field trips, business meetings and social gatherings all provide participants the opportunity to meet and share with their peers. The meeting will also commemorate the bicentennial of the the great 1811 and 1812 New Madrid earthquakes that forever changed the mid-western US landscape. In 2011 and 2012, there will be events held throughout the central United States observing the anniversary. For information on other bicentennial events please visit the New Madrid Bicentennial website.

Upcoming dates

Abstract Submission Deadline	11 January 2011
Program w/ Abstracts Online	25 February 2011
Meeting Pre-Registration Deadline	11 March 2011
Hotel Reservation Cut-Off	20 March 2011
Online Registration Cut-Off	1 April 2011

Ancient Earthquakes book

2010-12-28T13:35:00.000-05:00

This post qualifies for both my blogs, socarchsci.blogspot.com on archaeometry, and this one, shakingearth.blogspot.com on earthquakes.

The Geological Society of America has come out with a volume on Ancient Earthquakes, edited by Manuel Sintubin, Iain S. Stewart, Tina M. Niemi, and Erhan Altunel, 2010, 280 p., $85.

Ancient earthquakes are pre-instrumental earthquakes that can only be identified through indirect evidence in the archaeological (archaeoseismology) and geological (palaeoseismology) record. Special Paper 471 includes a selection of cases convincingly illustrating the different ways the archaeological record is used in earthquake studies. The first series of papers focuses on the relationship between human prehistory and tectonically active environments, and on the wide range of societal responses to historically known earthquakes. The bulk of papers concerns archaeoseismology, showing the diversity of approaches, the wide range of disciplines involved, and its potential to contribute to a better understanding of earthquake history. Ancient Earthquakes will be of interest to the broad community of earth scientists, seismologists, historians, and archaeologists active in and around archaeological sites in the many regions around the world threatened by seismic hazards. This Special Paper frames in the International Geoscience Programme IGCP 567 “Earthquake Archaeology: Archaeoseismology along the Alpine-Himalayan Seismic Zone.”

New Jersey earthquake

2010-12-27T19:40:00.002-05:00

You may recall that I have my (tongue in cheek) holiday quake hypothesis.

Well, sure enough, there was a Christmas day magnitude 2.0 earthquake in New Jersey!

U.S. Geological Survey

But of course, with about 1.5 million earthquakes every year above magnitude 2, about the threshold which will be felt by people if close enough, there are many such small quakes somewhere in the world every day.

Earthquakes in Israel

2010-12-25T13:29:00.002-05:00

Today being Christmas (not my own religious cup of tea), I thought I'd post on earthquakes in the "Holy Land."

The USGS has a page on earthquakes in Israel, as it does for many other regions of the world.

A sesimicity map from recent years shows the location of a number of small quakes along the Dead Sea Rift zone.

Israel actually seems to have little of the way of online resources, at least in English, about their earthquake situation, either through the Israel Geological Survey, or the Geophysical Institute of Israel. After the recent tragedy of the wildfires in the northern part of the country, I wonder if Israel is prepared for earthquake hazards, despite what appears to be a significant seismic risk:

GFZ German Research Centre for Geosciences

A good summary of the regional tectonics can be found in the 2007 Tectonophysics article "Stress tensor and focal mechanisms along the Dead Sea fault and related structural elements based on seismological data," by Rami Hofstetter et al.

Spacequakes

2010-12-24T12:57:00.002-05:00

I didn't know the term spacequakes before, but I came across it in an article in the Christian Science Monitor (a periodical and now web site that I respect, despite its origin and title).

Aurora (from Christian Science Monitor)
Like an earthquake in space, so-called spacequakes are temblors in Earth's magnetic field caused by plasma flying off the sun that could help generate the colorful auroras that dance high in Earth's atmosphere, a new study suggests.

"Magnetic reverberations have been detected at ground stations all around the globe, much like seismic detectors measure a large earthquake," said Vassilis Angelopoulos of UCLA.

And these rumbles can pack a punch. "The total energy in a spacequake can rival that of a magnitude 5 or 6 earthquake," according to Evgeny Panov of the Space Research Institute in Austria. Panov is first author of a paper reporting the results of a study on spacequakes in the April 2010 issue of Geophysical Research Letters.

Energies of earthquakes and other phenomena (from USGS)

I like it when different physical phenomena inter-relate! Especially this one, that crosses over from my major specialty within geophysics, which is actually not earthquakes/seismology but geomagnetism. So wholistic!

Carbon sequestration and earthquakes

2010-12-20T18:07:00.000-05:00

There were a few interesting talks at the American Geophysical Union meeting on geoengineering. Personally, I can't really figure out how mucking with natural systems, which got us into the global change conundrum we are now in, can still be seen as a viable approach, Aren't there likely to be further unknown and unforeseen consequences?

Stanford geophysicist Mark Zoback discussed the possibility of carbon sequestration causing small and moderate earthquakes. "While those earthquakes are unlikely to be big enough to hurt people or property, they could still cause serious problems for the reservoirs containing the gas. ... When we start perturbing the system by changing fluid pressure [as we inject massive amounts of carbon dioxide into the subsurface], we have the potential for activating faults," he said.

"The problem Zoback foresees is that the seismicity could create small pathways through the rock by which carbon dioxide would gradually seep back into the air. If the carbon dioxide permeates back out of the reservoir, the effort to keep it out of the atmosphere will have been futile," he said. In addition to failing to solve the problem, a lot of time and money would turn out to have been wasted."

Is the Haiti earthquake no longer newsworthy?

2010-12-19T17:25:00.000-05:00

Interesting that if you do a Google search for the AGU meeting and the Haiti earthquake, essentially nothing turns up. There was other news to come out of the AGU meeting, but I guess the Haiti story is just "old hat."

Dave Petley's AGU blogosphere Landslide blog did report on the specifics of the session I outlined in my last post. One of the speakers, Brian Mcadoo, is a friend and colleague who worked with me on an archaeological geophysics project in Jamaica in 1999. We probably didn't realize at the time that where we were working in Mandeville was not far from the westernmost extention of the Enriquillo-Plaintain Gardens fault zone which was related to the generation of the Haiti quake.

Haiti earthquake at the American Geophysical Union

2010-12-12T13:31:00.001-05:00

There will be a "union" session on the Haiti earthquake at the AGU. The oral presentations set for Monday morning are as follows. (The organizer Eric Calais was the subject of a recent post here.)

U11A Moscone South: 104 Monday 0800h

The 12 January 2010 M7.0 Haiti Earthquake

Presiding: E Calais, Purdue University; S E Hough, U.S. Geological Survey

0800h U11A-01 The January 12, 2010, Mw 7.0 earthquake in
Haiti: context and mechanism from an integrated geodetic study:
E Calais, A M Freed, G S Mattioli, F Amelung, S Jonsson, P E Jansma,
T H Dixon, C Prepetit, R Momplaisir

0815h U11A-02 The Role of Science and Engineering in Rebuilding
a More Resilient Haiti (Invited): D Applegate

0830h U11A-03 Networks in disasters: Multidisciplinary
communication and coordination in response and recovery to
the 2010 Haiti Earthquake (Invited): B G McAdoo, J Augenstein,
L Comfort, L Huggins, N Krenitsky, S Scheinert, T Serrant,
M Siciliano, S Stebbins, P Sweeney, Title of Team: University of
Pittsburgh Haiti Reconnaissance Team

0845h U11A-04 The Role of Science and Engineering in Response
and Reconstruction Following the 2010 Haiti Earthquake (Invited):
W D Pennington

0900h U11A-05 The Enriquillo-Plantain Garden Fault in Haiti:
Holocene Offsets and Seismic Hazard: C S Prentice, A J Crone,
P Mann, R D Gold, K W Hudnut, P Jean, R W Briggs

0915h U11A-06 The 2010 Haiti earthquake sequence: new insight
of the tectonic pattern from aftershocks and marine geophysical
data : Haiti-OBS cruise: B F Mercier De Lepinay, Y Mazabraud,
F Klingelhoefer, V Clouard, Y Hello, D Graindorge, B Marcaillou,
J Crozon, J Saurel, P Charvis, B S Mildor, A Deschamps, M Bouin,
J Perrot

0930h U11A-07 Seismic Monitoring and Post-Seismic
Investigations following the 12 January 2010 Mw 7.0 Haiti
Earthquake (Invited): J Altidor, A Dieuseul, W L Ellsworth,
D D Given, S E Hough, M G Janvier, J Z Maharrey, M E Meremonte,
B S Mildor, C Prepetit, A Yong

0945h U11A-08 Triggering of the 2010 Haiti earthquake by
hurricanes and possibly deforestation: S Wdowinski, I Tsukanov,
S Hong, F Amelung

Seismology at the American Geophysical Union

2010-12-11T09:14:00.000-05:00

I will mostly be at geomagnetism-paleomagnetism session at the huge AGU Fall meeting (15,000 attendees next week).

Among the many seismology sessions:

S41B
Moscone South: Poster Hall
Thursday 0800h
Engaging Citizens in the Collection of Earthquake
Observations Using the Internet I Posters (joint
with NH)
Presiding: R Bossu, EMSC; R W Clayton, Caltech

0800h S41B-2010 POSTER ShakeMapple: Tapping
Embedded Motion Sensors to Map the Felt Extents of an
Earthquake: L Kamb, G McGilvary, J van Hemert, R Bossu

0800h S41B-2011 POSTER RICHTER: A Smartphone
Application for Rapid Collection of Geo-Tagged Pictures of
Earthquake Damage: H Skinnemoen, R Bossu, K Furuheim,
E Bjorgo

0800h S41B-2012 POSTER Raising Seismic Awareness
on- and off-campus with class-built seismometers: K J
Ferguson, K Van Wijk, T Channel, R Nuxoll

0800h S41B-2013 POSTER Community Seismic Network
(CSN): R W Clayton, T H Heaton, M D Kohler, M Chandy,
A Krause

0800h S41B-2014 POSTER The Quake-Catcher Network:
Improving Earthquake Strong Motion Observations
Through Community Engagement: E S Cochran, J F
Lawrence, C M Christensen, A I Chung, C Neighbors, J
Saltzman

S51E
Moscone West:
2007 Friday 0900h
Engaging Citizens in the Collection of Earthquake
Observations Using the Internet II (joint with NH)
Presiding: R Bossu, EMSC; P S Earle, USGS

0900h S51E-01 The USGS “Did You Feel It?” Internetbased
Macroseismic Intensity Maps: Lessons Learned from a
Decade of Online Data Collection (Invited): D J Wald, V RQuitoriano, M Hopper, S Mathias, J W Dewey

0915h S51E-02 iShake: Mobile Phones as Seismic Sensors
(Invited): S Dashti, J Reilly, J D Bray, A M Bayen, S D
Glaser, E Mari

0930h S51E-03 The NetQuakes Project – Research-quality
Seismic Data Transmitted via the Internet from Citizenhosted
Instruments (Invited): J H Luetgert, D H
Oppenheimer, J Hamilton

0945h S51E-04 Flashsourcing or Real-Time Mapping of
Earthquake Effects from Instantaneous Analysis of the
EMSC Website Traffic: R Bossu, S Gilles, F Roussel

Northeast States Emergency Consortium

2010-12-09T21:33:00.003-05:00

The Northeast States Emergency Consortium (NESEC) is a non-profit all-hazards emergency management organization,. NESEC is the only all-hazard state consortium in the nation lead exclusively by State Directors of Emergency Management and is supported and funded by the Department of Homeland Security Federal Emergency Management Agency (FEMA). The states of Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island and Vermont form the consortium.

The Northeast is susceptible to many hazards, including earthquakes, hurricanes, floods, fires, hazardous materials incidents, terrorism, tornadoes, winter storms, ice jams and other natural and man-made disasters. Large, densely populated urban areas and extensive waterfront development have only increased the region's vulnerability to natural disasters.

The web site includes a cool web page with links to real time hazard maps.

Here is their K-5 level video on the earthquake hazard for New England:

FAQ on earthquakes, California style

2010-12-07T21:50:00.002-05:00

The Southern California Seismic Network has a pretty good page on frequently asked questions - what every person wants to know about earthquakes, with an emphasis on Southern California. For example, "Are we falling into the ocean soon?" (The answer is no.) Other pages on the site have data, seismograms, and more technical information. Go have a look.

Geophysicist Aims to Lower Seismic Risk in Haiti

2010-12-06T10:38:00.001-05:00

From the Chronicle of Higher Education (a great read for academics):

By Travis Kaya

Late one night in January, just 12 days after the earthquake that devastated Haiti, Eric Calais touched down at the shattered Port-au-Prince airport in the cockpit of a Boeing 727 weighed down with humanitarian aid and geology equipment. It was no consolation to the Purdue University geophysics professor that he had warned the nation's leaders two years earlier to ramp up their earthquake preparedness, after he projected that a 20-mile-long fault line under Haiti had the potential to cause a 7.2-magnitude quake.

Mr. Calais, 46, returned to Haiti for two reasons. He was leading a National Science Foundation mission to study the earthquake's epicenter while it was still fresh. And he wanted to check up on the friends he had made during two decades of visiting the island nation. Some of them, he would learn, had perished beneath the rubble.

"When a large earthquake occurs, geoscientists are always very interested in going to the earthquake site as quickly as possible because it's an opportunity to learn," Mr. Calais says. "But the priority after the earthquake was not doing science; it was humanitarian support."

In April he went back to Haiti to apply his geophysics expertise in a new role: developing public-safety policy as the co-chair of the United Nations Development Programme's Disaster Risk Reduction Task Force there. During his one-year term, Mr. Calais will work with Haitian scientists, government officials, and aid workers to build a permanent national agency for seismic-risk reduction that will teach government officials how to prepare for earthquakes. He will also advise international investors and organizations like the World Bank on seismic risk.

Mr. Calais traded his Purdue laboratory—where he has been since 2001—for a dusty steel freight container just outside the Port-au-Prince airport. He has braved the tropical heat and rain, and now has to be constantly vigilant against cholera.

Dealing with government bureaucracy and politics has meant a steep learning curve for scientists like Mr. Calais. Government and U.N. officials "think about these problems in different terms," he says. "I really had to twist my brain in a completely different way in order to operate."

He felt similarly in 2008, after nearly two decades of studying Northern Caribbean geology—starting with his dissertation at the University of Nice, in France—convinced him that Haiti was vulnerable to a seismic event. In meeting after meeting with government ministers and international donors, Mr. Calais says, the response to his warnings was always the same: "This is a very interesting story that you're talking about, but there is nothing that we can do about it."

Haitian officials, plagued for decades by political turmoil, hurricanes, and poverty, just had more immediate concerns, Mr. Calais says.

But that attitude has changed. When efforts to rebuild the country began after the earthquake, the Haitian government was paying much more attention to what was happening beneath its feet. The United Nations and foreign-aid agencies shared its concern. And Mr. Calais's experience bridging the policy and science divide made him a natural choice to lead risk-reduction efforts, said Thomas Pitaud, technical specialist for the U.N. disaster-relief-management program. "We cannot develop the country without having a good knowledge of the risk."

Though planning has just begun, Mr. Calais has had an early victory in gaining the government's support for seismic microzoning—studying regional geology to identify plots of land most prone to destruction during a quake. The prime minister and public-works agencies are reviewing microzoning data collected immediately after the quake, which will direct reconstruction for the entire capital city of Port-au-Prince, and hope to survey other urban areas once the money is available.

Developing a national seismic-risk-reduction plan will require considerable investment in education. According to Mr. Calais, Haiti has a shortage of geologists and engineers trained to do the survey work, and many Haitian researchers have left government and academe for better-paying jobs in industry. "Even though there are potential scientists and researchers, they do other things on the side," he says. "They are very busy making money and trying to sustain their families."

That leaves the majority of research work to visiting scientists and graduate students from the United States and Europe, who take their expertise with them when they leave.

Mr. Calais has an even greater worry. The Haitian fault line released only about 10 percent of its stored energy when it shifted last January, and the remaining energy could set off an even larger quake at any time, he says. Although the plates beneath Haiti had been pretty stable for 50 years, he says, the country has a long history of seismic activity. "It gives us a false impression of safety," he says. When the earth is quiet, he says, "it's storing the energy it needs" for its next release.

Kudos to Dr. Calais for applying his expertise in a humanitarian fashion.

USGS publication on the San Andreas Fault

2010-12-05T11:50:00.000-05:00

Next week I'll be at the American Geophysical Union meeting in San Francisco, where I have co-organized a session on Magnetism of Glassy Materials.

I may fly over the Carrizo Plains, where one can get a beautiful view of the San Andreas Fault, and see how it has offset stream channels in a right lateral strike skip fashion (see photo at right).

One can read up on the San Andreas Fault in the U.S Geological Society Professional Paper 1515, edited by Robert E. Wallace, available online.

512 Wenchuan China earthquake

2010-12-04T09:48:00.001-05:00

I learned from one of my Chinese students that in China the numbers 512 have the same kind of tragic resonance as 911 does in ours. It is code for the May 12, 2008 magnitude 8.0 Wenchuan earthquake, one of the most destructive earthquakes to occur around the world in recent decades. About 70,000 people died, and 400,000 were injured.

George C. Lee, SUNY Distinguished Professor and Samuel P. Capen Professor of Engineering, presented a seminar titled The 512 Wenchuan Earthquake of China--A Preliminary Report (download the 112 page pdf via the link) on June 16, 2008 at MCEER (Multidisciplinary Center for Earthquake Engineering Research) at the University at Buffalo, which summarized preliminary observations gathered from the internet, media, and earthquake engineering colleagues and contacts in China. He also presented a number of possible lessons learned for structural engineers, which may serve as possible foci for future in-depth research studies and field reconnaissance missions.

Measuring Earthquakes in Western New York

2010-12-02T18:03:00.000-05:00

From the web pages of the Lamont-Doherty Earth Observatory:

Each year, dozens of small, mostly harmless earthquakes quakes rattle the northeastern United States and southern Canada, and one quite active area runs along the shores of lakes Erie and Ontario, in western New York. In order to learn more about what generates these, and the possible threat of something bigger, scientists at Columbia University’s Lamont-Doherty Earth Observatory have installed a new seismometer at the West Valley Central School, southeast of Buffalo. Officially announced on Oct. 15, it is the latest addition to the Lamont Cooperative Seismic Network, which monitors earthquakes throughout the region. The station not only sends data to the scientific community, but gives hands-on experience to West Valley students, who have been given computer hardware and software t0 analyze signals from the instrument.

Funded with a $25,000 grant from the New York State Energy Research and Development Authority, the station was installed by Lamont seismologist Won-Young Kim, head of the network. There are now 28 stations including this one, from New York’s Central Park to near the Canadian border. Many are run in cooperation with schools, universities, museums and other organizations. Signals are sent in real time to Lamont, and disseminated to scientists worldwide via the internet.

Some earthquake statistics and graphs

2010-11-29T22:12:00.002-05:00

I'm going through some browser bookmarks and saving them to my Delicious lists, and listing some here as I go.

There are some nice data sets and some linked visualizations of earthquake statistics on this page from the U.S. Geological Survey. As copied in the table below (click on it for a larger version), Note that the number of quakes above magnitude 6 have not increased over time. There is an apparent increase in the number of smaller earthquakes, but this is an artifact of better seismograph networks.

Blockbuster Chinese film on earthquakes

2010-11-27T11:44:00.001-05:00

From the New York Times:

To call “Aftershock” a melodrama doesn’t really do it justice. Shortly after Feng Xiaogang’s film begins, a woman whose husband has just died in the devastating 1976 Tangshan earthquake looks up and screams: “God! You bastard!” And things go downhill from there. Before you know it, she has a Sophie’s choice to make involving her two trapped children and a concrete slab. These scenes, including a highly effective rendering of the earthquake, which killed an estimated 240,000 people, are dispatched quickly. But the pain is just beginning. — Mike Hale

The full NY Times review is here.

And here is the trailer:

2009, Disasters in Numbers - Earthquakes often are the worst

2010-11-27T07:56:00.000-05:00

From the United Nations ISDR (International Strategy for Disaster Reduction):

According to the Centre for Research on Epidemiology of Disasters, 3,852 disasters killed more than 780,000 people over the past ten years, affected more than two billion others and cost a minimum of 960 billion US$. This is from the report 2009: Disasters in Numbers.

In the past decade, nearly 60 per cent of the people killed by disasters died because of earthquakes. After earthquakes, storms (22%) and extreme temperatures (11%) were the most deadly disasters between 2000 and 2009.

The most deadly disasters of the 2000 decade were the Indian Ocean Tsunami, which hit several countries in Asia (2004) leaving 226,408 dead; Cyclone Nargis, which killed 138,366 people in Myanmar (2008); and the Sichuan earthquake in China (2008), causing the deaths of 87,476 people. 73,338 people were also killed in the earthquake in Pakistan (2005) and 72,210 in heat waves in Europe (2003).

In 2009, the total number of people killed and affected by disasters was lower than in 2008, as no major disaster occurred: 327 events killed 10,416 people, affected nearly 113 million others and caused a total of 34.9 billion US$ economic damages.

New book on Midwestern earthquake hazard

2010-11-23T20:34:00.001-05:00

Disaster Deferred: How New Science Is Changing our View of Earthquake Hazards in the Midwest
Seth Stein

Columbia University Press

October, 2010
Cloth, 296 pages, 55 halftones, 38 line drawings, 2 tables
ISBN: 978-0-231-15138-2
$27.95 / £19.95

Although the government claims that parts of the Midwest face earthquake danger equal to or greater than California's, new science over the past 20 years shows that these claims are exaggerated. The series of earthquakes that struck Missouri 200 years ago were much smaller than the public has been led to believe. There are no signs that similar large earthquakes are likely to happen in the next few hundred years. The billions of dollars needed to bring buildings in parts of the Midwest like Memphis and St. Louis up to California's earthquake resistant standards are a waste of taxpayer money and divert dollars from far worthier causes.

In the winter of 1811-12, a series of large earthquakes in the New Madrid seismic zone-often incorrectly described as the biggest ever to hit the United States-shook the Midwest. Today the federal government ranks the hazard in the Midwest as high as California's and is pressuring communities to undertake expensive preparations for disaster.

Coinciding with the two-hundredth anniversary of the New Madrid earthquakes, Disaster Deferred revisits these earthquakes, the legends that have grown around them, and the predictions of doom that have followed in their wake. Seth Stein clearly explains the techniques seismologists use to study Midwestern quakes and estimate their danger. Detailing how limited scientific knowledge, bureaucratic instincts, and the media's love of a good story have exaggerated these hazards, Stein calmly debunks the hype surrounding such predictions and encourages the formulation of more sensible, less costly policy. Powered by insider knowledge and an engaging style, Disaster Deferred shows how new geological ideas and data, including those from the Global Positioning System, are painting a very different-and much less frightening-picture of the future.

Seth Stein is Deering Professor of Geological Sciences at Northwestern.

To read an interview with the author or to find out more about this work go to:
http://www.cup.columbia.edu/book/978-0-231-15138-2/disaster-deferred/webFeatures

New book on Ancient Earthquakes

2010-11-23T16:04:00.001-05:00

Geological Society of America
Ancient Earthquakes
Editors: Manuel Sintubin, Iain S. Stewart, Tina M. Niemi, Erhan Altunel
2010, 280 p., $85
ISBN 9780813724713

Ancient earthquakes are pre-instrumental earthquakes that can only be identified through indirect evidence in the archaeological (archaeoseismology) and geological (palaeoseismology) record. Special Paper 471 includes a selection of cases convincingly illustrating the different ways the archaeological record is used in earthquake studies. The first series of papers focuses on the relationship between human prehistory and tectonically active environments, and on the wide range of societal responses to historically known earthquakes. The bulk of papers concerns archaeoseismology, showing the diversity of approaches, the wide range of disciplines involved, and its potential to contribute to a better understanding of earthquake history. Ancient Earthquakes will be of interest to the broad community of earth scientists, seismologists, historians, and archaeologists active in and around archaeological sites in the many regions around the world threatened by seismic hazards. This Special Paper frames in the International Geoscience Programme IGCP 567 “Earthquake Archaeology: Archaeoseismology along the Alpine-Himalayan Seismic Zone.”

Seismologist Eugene T. Herrin obituary

2010-11-23T15:44:00.001-05:00

From Southern Methodist University:

Dr. Eugene T. Herrin Jr., an internationally respected seismologist and holder of the Shuler-Foscue Endowed Chair in the Roy M. Huffington Department of Earth Sciences at SMU, died of a heart attack on November 20, 2010.

A professor at SMU since 1956, Herrin was known for his pioneering work in detecting nuclear explosions. He discovered that certain wave generators, including explosions and earthquakes, create not only seismic waves but also infrasound waves. Based on that discovery, Herrin was one of the first proponents of using seismo-acoustic analysis to distinguish the difference between mining explosions, earthquakes and underground nuclear weapons tests.

“Dr. Herrin’s work has played a critical role in establishing accurate worldwide monitoring of nuclear tests,” said Brian Stump, professor of Earth sciences and the Claude C. Albritton, Jr. Chair in the Huffington Department of Earth Sciences. “His research was fundamental in creating the international monitoring network that enforces the Comprehensive Nuclear Test Ban Treaty.”

Herrin’s first breakthrough in experimental seismology occurred in 1963 when he determined that the earth’s mantle is not laterally homogeneous as previously thought. He won the Grove Karl Gilbert Award from the Geological Society of America for this contribution.

Geoblogging the Geoblogosphere

2010-08-23T18:19:00.001-04:00

From GSA (Geological Society of America) Connections:

Each month (or thereabouts), the themed geology blog carnival "Accretionary Wedge" invites geoblogger contributions. July's theme, the role of geoblogosphere, generated quite a bit of activity. A synthesis of contributions is hosted on the History of Geology blog site as "Accretionary Wedge #26: The role of the Geosphere" (30 July). The following is a sampling of blog posts on the topic:

I haven't actively sought to be linked into the geoblogosphere, but I guess I belong there.

World's largest seismically protected building (?)

2010-08-15T23:06:00.001-04:00

Not the largest building, or the seismically safest (which would presumably be in an aseismic zone), but I guess this means the most expensively protected building in a seismically active zone.

This seems to have been San Francisco International Airport at one point, protected by 267 huge ball bearings. (I came across this while reading about bearings, because my paleomagnetic spinner magnetometer needed to have its bearings oiled.)

But, according to a more recent article from Wired magazine, the record now goes to the Istanbul Airport.

The world’s largest seismically isolated building, the new international terminal at Istanbul’s Sabiha Gökçen Airport, is now complete and open for business.

Stretching across more than 2 million square feet, the terminal doesn’t sit directly on the soil, but rather on more than 300 isolators, bearings that can move side-to-side during an earthquake. The whole building moves as a single unit, which prevents damage from uneven forces acting on the structure.

“What an isolation system does is that it enables the building to move through large displacements in unison, and in doing that, you absorb earthquake energy,” said Atila Zekioglu, the engineer at the firm Arup, who designed the building.

Earthquakes accelerate buildings laterally, whipping them back and forth. Isolators (see photo below) slow down the motion of the building. In the case of the new terminal, the building will only have to withstand one-fifth of the acceleration that it would have had to without the earthquake proofing.

The company Earthquake Protection Systems was a principal in both projects.

Love Waves

2010-08-08T11:26:00.000-04:00

I've been a bit blog-lazy lately, but I'll see if I can get back in the swing.

The occasional posts by the Berkeley Seismological Laboratory are well researched, written, and composed. The latest BSL blog post was about surface (aka L) waves, waves that travel near the surface of the earth. Body waves, so-called P and S waves, are push-pull and shear waves that travel through the Earth's interior. The two types of surface waves, Love and Rayleigh waves, are named after physicists A.E.H. Love and Lord Rayleigh, who worked out the theory of their existence. Body waves provide an "x-ray"-type information of the Earth's interior, while surface waves provide models of the Earth's crust.

I heart Love waves.

Location of Maryland earthqauke

2010-07-18T09:45:00.001-04:00

Below is a map posted by the U.S. Geological Survey showing the epicenter of Friday's magnitude 3.6 earthquake in the Washington D.C. area.

The red dot marking the epicenter is adjacent to the major highway 270 which runs from upper left to lower right in the map.

For conspiracy enthusiasts among you, note that just a few hundred meters away you will see the U.S. Department of Energy, formerly the Atomic Energy Commission.

I know this because my first real job after college was with Fairchild Space and Electronics Company, an aerospace firm located across the street. I annotated Fairchild on the map below, although I don't know what is located there now.

Washington area shaken by earthquake

2010-07-17T11:22:00.001-04:00

Below is a copy of the mini-poster I put up on our seismograph, showing the signal observed here at F&M, about 150 km from the epicenter. More to come.

CBC coverage of the Quebec quake

2010-07-11T19:15:00.000-04:00

Canadian Broadcasting Company has some nice coverage of the recent Quebec quake, as well as related material on the earthquake hazard across Canada.

But in typical Canadian fashion, this photo of a toppled woodpile elicited some pondering about how disastrous Canadian quakes might really be. Zut alors!

Magnitude 5 Quebec quake

2010-07-07T18:38:00.001-04:00

I was out of town when this one hit near the Canada-U.S. border:

From the USGS:

The June 23, 2010 Val-des-Bois, Quebec earthquake occurred at 1:42 pm local (eastern) time 56 km (35 miles) north of Ottawa, Ontario, Canada's capital city. The preliminary estimate of magnitude (M) is 5.0, at a depth of 16 km (10 miles).

This earthquake occurred near the southern edge of the Western Quebec Seismic Zone. Earthquakes within this zone are mostly small. They tend to cluster in a wide area that is slightly elongated northwest-southeast. Historically, earthquakes in the Western Quebec Seismic Zone have caused damage roughly once a decade. Three or four smaller events each year are felt in the region but are generally too small to cause damage. Still smaller earthquakes are much more common. The largest earthquakes known in this part of Canada occurred in 1935 (M6.1), about 250 km (150 miles) to the northwest of the Val-des-Bois event, and in 1732 (M6.2), about 150 km (100 miles) to the east of the earthquake. The 1732 earthquake caused significant damage in Montreal.

I heard of one Toronto resident who literally felt her bed rolling back and forth. A colleague in Syracuse felt the earth shake as well. This intensity map from the event shows that she was not alone:

Open letter to the President of the Republic of Italy

2010-07-04T12:28:00.000-04:00

From the website of the Italian Istituto Nazionale di Geofisica e Volcanologia:

Two weeks ago in Italy, the L’Aquila Prosecutor’s office indicted scientists, some of them members of the “Commissione Grandi Rischi”(Commission for High Risks), and civil protection officials for manslaughter. The basis for the indictment is that these people did not provide a short-term alarm to the population after a meeting of the Commission held in L’Aquila six days before the Mw 6.3 earthquake that struck that city and the surrounding area.

The allegations against the scientists are completely unfounded. Years of research worldwide have shown that there is currently no scientifically accepted method for short-term earthquake prediction that can reliably be used by Civil Protection authorities for rapid and effective emergency actions.

The international seismological community has long recognized that the best approach to defending populations from catastrophic earthquakes is not through earthquake prediction, but through risk mitigation and the application of appropriate safety measures to prevent buildings from collapsing. In this regard, the development of seismic hazard maps, which provide estimates of the probability of occurrence of predefined values of peak ground motion in a given time period, provide the specifications required by building codes to avoid collapse of buildings and the resulting fatalities

Italy is an earthquake-prone country. An improved seismic hazard map that summarizes decades of research on earthquake occurrence and effects was completed in 2004 (see http://zonesismiche.mi.ingv.it/). It is the result of the work of many scientists, it is considered to be one of the best seismic hazard maps in Europe, and it has been used as a basis for the Italian building code beginning in 2008 (“Norme Tecniche per le Costruzioni”, GU n.29 del 04/02/2008). It should be viewed as the primary contribution of the Italian earthquake scientists to their Country.

Seismic hazard maps must also be used for conveying to the population the basic concepts of earthquake hazard, awareness, preparedness, and response. Increased consciousness of the earthquake hazard and associated risk should also foster further prevention actions by national and local authorities. Overall, earthquake preparedness and damage prevention in the form of retrofitting are not only possible but mandatory in a country affected for the most by moderate size earthquakes that often result in catastrophes for the society because of the large percentage of seismically unreinforced buildings.

Education, awareness, preparedness and retrofitting are the best tools for mitigating the impact of the catastrophic earthquakes that will inevitably affect Italy in the future.

The scientific community involved in earthquake science urges the Italian government, local authorities and decision makers in general, to be proactive in establishing and carrying out local and national programs to support earthquake preparedness and risk mitigation rather than prosecuting scientists for failing to do something they cannot do yet - predict earthquakes.

The President of the Italian Republic is the head of state of Italy and represents national unity. The president's term of office lasts for seven years. The current President of the Republic is Giorgio Napolitano, elected in 2006.

Scientists May Face Manslaughter Charges After Earthquake

2010-07-01T17:37:00.000-04:00

American Geophysical Unon Science Policy Alert 10-18: 22 June 2010

Seven Italian scientists and government officials are under investigation on charges of manslaughter for failure to warn the city of L’Aquila, Italy, before an earthquake hit last year, killing hundreds. The scientists and officials under investigation, who are employees of the National Institute for Geophysics and Volcanology (INGV) and the Civil Protection Department, took part in a meeting of the Major Risks Committee on 31 March 2009. At the meeting, the committee told L’Aquila city officials that “just because a small series of quakes has been observed [in L’Aquila] there is no reason to suggest that the sequence of low-magnitude tremors are a precursor to a major event,” which was deemed “improbable, although not impossible.” However, on 6 April 2009, the city was struck by a Mw 6.3 earthquake that killed 308 people.

The criminal charges against these scientists and officials are unfounded. Despite decades of scientific research in Italy and in the rest of the world, it is not yet possible to accurately and consistently predict the timing, location, and magnitude of earthquakes before they occur. It is thus incorrect to assume that the L’Aquila earthquake should have been predicted. The charges may also harm international efforts to understand natural disasters and mitigate associated risk, because risk of litigation will discourage scientists and officials from advising their government or even working in the field of seismology and seismic risk assessment.

Science is making critical contributions to the understanding and mitigation of earthquake hazards in Italy and the world. Examples include providing tools such as seismic risk maps to determine areas of greatest vulnerability, improving seismic wave analysis so that we can better understand how the Earth moves during an earthquake, and increasing our capabilities for seismic monitoring and for providing rapid information on earthquake location and severity for early warning systems and first responders.

It is in the best interest of all countries to reduce earthquake vulnerability through awareness, preparation, and mitigation. Local government officials should work with scientists and engineers to prepare for seismic hazards in that region. To truly mitigate earthquake risk, governments must utilize the long-term hazard assessment, post-earthquake Shake Maps, and other tools created by seismologists to educate residents and inform sound infrastructure policy. Communities can increase their earthquake preparedness through implementation of building codes based on these long-term hazard assessments, retrofitting older buildings, improving emergency response, and increasing public awareness of the hazard and individual responsibility during and after these tragic events.

In support of the Italian scientists and officials, the INGV has written an open letter to the President of the Republic of Italy. The letter is open for public signatures and, as of 21 June 2010, has 5,028 signatories from around the world, many of whom are geoscientists. Please sign the letter and pass this information on to your colleagues if you support these seven scientists and officials and their right to conduct best scientific practices without risk of persecution.

Seismicity of Azerbaijan

2010-06-10T19:07:00.000-04:00

I'll be away in Azerbaijan the next three weeks or so, working at the Oglanqala archaeological site doing magnetometry.

The Azerbaijani National Academy of Sciences Geology Institute says:

Genetically seismicity of Azerbaijan is associated with activity of seismogenic structures in the Lesser Caucasus and in the Greater Caucasus Ridges. In the most territory of Azerbaijan earthquakes of magnitude M=6-6.5 may take place and in some seismogenic structures one can expect seismic events of a maximum magnitude up to M=7. This indicates that on the whole the territory of Azerbaijan and the adjacent part of the Caspian depression have a moderate seismicity. Though for the recent period in the Caucasus region there have not been recorded any seismic events of magnitude M>7-7.2, from the point of view of their peculiar features this region is characterized by a high engineering-geologic risk. This distinguishes the territory of Azerbaijan from the Pacific mobile belt where intensity of earthquakes by Richter's scale is M=8-8.5.

The English isn't the best, but try learning Azerbaijani!

Figure from ENVSEC

I'll be in the bottom left area of the map, not far from Ararat.

See you in July.

New Jersey quake

2010-06-06T15:38:00.005-04:00

A small magnitude 2.3 quake occurred this morning in New Jersey.

Here is the info from LCSN:

MAG    DATE    LOCAL-TIME  LAT     LON    DEPTH    LOCATION
        y/m/d     h:m:s     deg     deg     km

2.3  2010/06/06 04:13:45 40.417N 74.313W  5.0 15 km N of Barnegat

2.3  2010/02/21 12:31:57 40.714N 74.680W  5.0 24 km WSW of Morristown

2.6  2010/02/21 08:59:25 40.717N 74.658W  5.0 22 km WSW of Morristown

1.2  2010/02/06 21:52:48 40.734N 74.658W  2.0 21 km WSW of Morristown

1.5  2010/02/05 05:50:28 40.731N 74.656W  2.0 21 km WSW of Morristown

2.0  2009/12/26 18:53:13 40.878N 74.550W  6.0 12 km WSW of Boonton

Video report on Dillsburg earthquake

2010-06-04T10:52:00.001-04:00

From York Fox News 43:

Dillsburg, PA, magnitude 2.9

2010-06-03T10:51:00.001-04:00

Dillsburg area shaken by another earthquake

CARL LINDQUIST -- The York Dispatch

Updated: 06/03/2010 10:12:24 AM EDT

An earthquake measuring 2.9 on the Richter Scale struck Northern York County on Thursday morning.

The U.S. Geological Survey reported the earthquake hit the area at 8:25 a.m. Thursday. The Geological Survey said the earthquake was about 3 miles from Wellsville and 4 miles from Dillsburg.

The earthquake that struck Thursday matched the strength of the strongest previous earthquake to hit the area. It occurred in April 2009.

Franklin and Marshall College seismogram

Local geologist Jeri Jones said several people called him Thursday morning to report an earthquake.

One caller told him pictures were knocked off the wall of her home, he said. Another caller said a relative in Mechanicsburg also felt shaking.

York County 911 also reported people calling to report an earthquake. No injuries or damage was reported.

The quake that hit Thursday continues the seismic activity reported in the Dillsburg area, which has been rattled by hundreds of distinct tremors since October 2008. Jones said the last major seismic activity occurred on Oct. 25, when the U.S. Geological Survey reported a series of earthquakes with magnitudes of 1.8, 2.6 and 2.8.

Chile Earthquake: NSF Research Grants

2010-05-28T15:42:00.001-04:00

From the National Science Foundation, May 3, 2010:

In response to the magnitude 8.8 earthquake that occurred in Chile on February 27, 2010, the National Science Foundation (NSF) has awarded three major Rapid Response Research (RAPID) grants to study how the quake happened, and learn from those findings for the future.

The Chile quake is the fifth largest earthquake ever recorded, and the second largest that has occurred since a modern suite of instruments was developed to collect data related to earthquakes.

"The new deployments will provide valuable data to help scientists understand earthquakes not only in Chile, but around the world," says Russ Kelz, program director in NSF's Division of Earth Sciences. "NSF is stimulating important advances in basic earthquake science, rapid-response geophysical and data communications technology, and international collaboration and data sharing."

Two NSF RAPID awards--made to a consortium of institutions including Ohio State University, California Institute of Technology, University of Hawaii, University of Memphis, and UNAVCO Inc., in Boulder, Colo.--provide for installation of 25 continuously operating global positioning system (CGPS) stations, as well as state-of-the-art satellite communications for data delivery.

Through another Chile quake RAPID award, 60 seismic stations arrived in Santiago, Chile, from the NSF-supported Incorporated Research Institutions for Seismology (IRIS) Program for Array Seismic Studies of the Continental Lithosphere (PASSCAL) Instrument Center in Socorro, New Mexico.

With data from the instruments, scientists will obtain high-resolution locations of aftershocks, carry out research on Earth structure in and around the Chilean subduction zone, and study major cities for a detailed analysis of local response.

All data collected as part of the U.S. deployments will be open and freely available immediately after collection.

More information about these RAPID projects may be found in IRIS Community Instrument Deployment in Chile and Science Highlights 2010 - UNAVCO Event Response.

Berkeley blog - Mount St. Helens and earthquakes

2010-05-20T19:20:00.000-04:00

Flying back from Germany a week ago Saturday, our plane was diverted over Iceland to get north of the ash cloud blowing from the Eyjafjallajökull volcano towards Spain. This caused a delay of two hours, not bad compared to what others have experienced, and I got to see the ash cloud from the south-facing windows. First time I have ever seen an erupting volcano. Pretty cool, even though it was a volcanic eruption. The dark cloud was nearly vertical, before it topped out, and then headed off towards Spain.

Anyway, it is now thirty years since the last large volcanic eruption in the conterminous United States at Mount St. Helens. The Berkeley Seismo Blog has a nice description of the harmonic tremors that reflected the magma moving within the volcano, and then the 5.1 magnitude earthquake that triggered slope failure of the mountain and the explosive volcanism.

Small earthquakes continue to occur. Check out the graphics and info at the Pacific Northwest Seismic Network.

Congressional hearing on reducing earthquake risk

2010-05-18T17:49:00.000-04:00

Congressional Briefing -- Citizen Science and Earthquakes: Reducing the Risk Through the Power of People

Released: 5/12/2010 1:19:54 PM
Contact Information:
U.S. Department of the Interior, U.S. Geological Survey
Office of Communication
119 National Center
Reston, VA 20192 Clarice Nassif Ransom 1-click interview
Phone: 703-648-4299
Clarice Ransom: cransom@usgs.gov

In the United States, 1 in 4 people live with the risk of earthquakes. The U.S. Geological Survey and its partners are designing innovative tools to better detect earthquakes and share critical information. The involvement of citizens is key, as decisions made before and immediately after an earthquake can save lives and protect property.

What: The USGS will host a congressional briefing on how innovative tools combined with citizen involvement can help save lives and minimize economic losses from earthquakes.

Who: Jack Hayes, Director, National Earthquake Hazards Reduction Program (emcee)
David Wald, U.S. Geological Survey
John Hooper, Director of Earthquake Engineering at Magnusson Klemencic Associates
Mark Benthien, Southern California Earthquake Center

Where: 1334 Longworth House Office Building
Washington, D.C

When: Friday, May 21, 2010
10 a.m.

Question on Irish earthquake

2010-05-11T12:22:00.002-04:00

A question was posted to an old post on the largest earthquake near Ireland, about where it was felt.

So, here is the map to answer that question, from the British Geological Survey:

Read about the European intensity scale numbers here.

LCSN web pages need updating

2010-05-07T14:59:00.003-04:00

It's not easy to keep on top of our web pages, blogs, wikis, etc.

But the LCSN web pages (yes, the LCSN that this is related to) need to be updated.

There are broken links.

There are "current" web pages that are months or even years out of date.

There are a number of excellent pages that are automatically updated with data from the LCSN network, and from elsewhere.

But for the site as a whole to be effective for public outreach, it needs to be better maintained.

Some earthquake software

2010-05-06T02:55:00.000-04:00

While I was preparing the last entry, I came across some software available through the USGS web pages.

Note that FORTRAN lives!

These are:

3D Focal Mechanisms - a tool for viewing earthquake focal mechanism symbols three dimensionally
3D velocity modeling
Cleanstrain - a program to process strainmeter data.
CLUSTER2000 - recognizes clusters in space-time in an earthquake catalog
Coulomb 3 - designed to investigate Coulomb stress changes on mapped faults and earthquake nodal planes
FPFIT - a Fortran program that computes double-couple fault plane solutions from P-wave first motion data
Ground Motion Parameter Calculator
HASH - a Fortran 77 code that computes double-couple earthquake focal mechanisms from P-wave first motion polarity observations
HypoDD - a Fortran computer program package for relocating earthquakes with the double-difference (DD) algorithm
HYPOINVERSE2000 - determines earthquake locations and magnitudes from seismic network data like first-arrival P and S arrival times, amplitudes and coda durations
MacR1D - a one-dimensional seismic travel-time calculator for Macintosh
MacRay - a general purpose two-dimensional seismic ray-tracer for Macintosh
OpenSHA - an effort to develop object-oriented, web- & GUI-enabled, open-source, and freely available code for conducting Seismic Hazard Analyses
PQLX - open-source software system for evaluating seismic station performance and data quality
Probabilistic Seismic Hazard Calculation Software
Quake Data Distribution System (QDDS) - provides a method for distributing earthquake data over the Internet in near-real time
The Quake Data Merge Real Time Merged Catalog (QDM) software
SATSI (Spatial And Temporal Stress Inversion) - inverts focal mechanism data for a spatially and/or temporally varying stress field
ShakeCast - delivers maps of areas affected by an earthquake
Slick Package - uses fault slip data (either field observations or from focal mechanism) to find the stress tensor that best explains the observations
Slope Performance During an Earthquake

Funding for earthquake monitoring

2010-05-05T13:08:00.001-04:00

Released: 5/3/2010 10:53:30 AM
Contact Information:
U.S. Department of the Interior, U.S. Geological Survey
Office of Communication

More than $7 million in cooperative agreements will be awarded for earthquake monitoring by the U.S Geological Survey in 2010. This funding will contribute to the development and operation of the USGS Advanced National Seismic System (ANSS).

“Earthquake monitoring is absolutely critical to providing fast information to emergency-response personnel in areas affected by earthquakes, so by building and repairing those monitoring systems, these cooperative agreements literally save lives and property,” said Secretary of the Interior Ken Salazar.

As part of the National Earthquake Hazards Reduction Program, the ANSS provides continuous, real-time monitoring of earthquake activity and collects critical information about how earthquake shaking affects buildings and structures. Funds are also being provided for the operation of geodetic monitoring networks, which detect minute changes in the earth’s crust caused by faulting in earthquake-prone regions.

“The ultimate goal of earthquake monitoring is to save lives, ensure public safety, and reduce economic losses,” said Bill Leith, a USGS scientist and coordinator of the ANSS. “Rapid, accurate information about earthquake location and shaking has greatly improved the response time of emergency managers following an earthquake.”

Nationwide, 39 states are considered to be at moderate-to-high risk of a damaging earthquake. Although the frequency of earthquakes on the West Coast is higher than other areas of the United States, many eastern cities are also at risk, including St. Louis, Mo., Memphis, Tenn., New York, N.Y., Boston, Mass., and many others.

A complete list of funded projects and reports can be found on the USGS Earthquake Hazards Program website.

Grants for the Northeast include:

G10AP00014
Laurence Becker, Northeast States Emergency Consortium
Utilizing the Surficial Geology of the Northeast United States to Improve NEHRP Site Effect Classifications in HAZUS-MH
$14,908; January 2010 through December 2010

G10AP00022
Eric Calais, Purdue University
Intraplate strain and stress in the North American plate interior: Collaborative Research with Purdue University and University of Wisconsin
$140,323; January 2010 through December 2011

G10AP00024
Dennis DeMets, University of WIsconsin, Madison
Intraplate Strain and Stress in the North American Plate Interior: Collaborative Research with Purdue University and University of Wisconsin
$26,092; January 2010 through December 2011

G10AP00037
John Ebel, Boston College
Analysis of Aftershock Sequences for Use in Predicting Aftershock Probabilities Immediately Following Strong Earthquakes
$42,867; January 2010 through December 2010

Happy Earth Day

2010-04-22T03:53:00.002-04:00

I still remember the first one 40 years ago!

Editorial Cartoon by John Sherffius

From AAES (The Association of American Editorial Cartoonists)

May the Earth and us have a more benign relationship together!

Safe travels, everyone.

China earthquake, magnitude 6.9

2010-04-14T13:03:00.000-04:00

From the Christian Science Monitor:

Striking around dawn while many locals were at home, the quake collapsed buildings in Jiegu Township, near the epicenter, trapping hundreds under rubble, Huang Limin, deputy secretary-general of the Yushu Tibetan Autonomous Prefecture, told the state-run Xinhua News Agency.

More than 85 percent of the houses in Jiegu, a town of 100,000 people, were destroyed, Zhuo Huaxia, a prefectural official told Xinhua: "The streets in Jiegu are thronged with panicked, injured people, with many bleeding in the head. Many students are buried under the debris due to building collapse at a vocational school."

With memories of the 2008 earthquake in neighboring Sichuan Province still strong, the government’s response to this disaster will be closely watched, particularly since the quake zone is in a poor area largely inhabited by ethnic Tibetans.

Location map from USGS

Here is the seismogram as recorded on the Franklin & Marshall College seismograph:

Accelerographs for PCs

2010-04-14T02:45:00.006-04:00

There was a question to one of my old posts about the availability of motion sensors for PCs, like Seismac for the Macintosh, which could turn your PC into an accelerograph.

Our friend IRIS (Incorporated Research Institutions for Seismology) comes through with a posted activity,

Exploring three-component seismic data with accelerometers.

This exercise refers you to the QCN site at Stanford which allows you to download software. The software not only works with a Mac laptop (2006 or later), but also a Thinkpad (2003 or later), or a desktop with a USB sensor.

In addition, you can purchase an external USB accelerometer (for Macs, PCs and Linux) can be purchased from the Quake Catchers Network (request a sensor on right hand menu).

(Or, buy a Macintosh!)

Mexicali earthquake poster

2010-04-09T02:28:00.001-04:00

The USGS has produced another in its fine series of posters on significant earthquakes.

The latest is on the magnitude 7.2 Mexicali quake.

Click on the image for a larger version

I won't dissect it in detail as I did for the Chile quake, but in the next post, we'll look at the fault plane solution, and its relation to the San Andreas Fault.

Mexicali quake magnitude same as Haiti quake

2010-04-06T04:05:00.001-04:00

Here is the usual good story (text and audio) from NPR, explaining in part why despite the similar magnitudes for these two quakes, damage in Mexicali was less. Many aftershocks are still occurring.

Mexicali is the capital of the Mexican state of Baja California, with a metropolitan population close to 1 million people.

Earthquake coverage in the LA Times

2010-04-05T10:57:00.000-04:00

For recent updates on the Mexicali quake, see the LA Times.

More soon - I have ballet tickets.

Quake near California-Mexico border

2010-04-05T03:12:00.001-04:00

== PRELIMINARY EARTHQUAKE REPORT ==
California Integrated Seismic Net
USGS/ Caltech/ CGS/ UCB/ UCSD/ UNR
Version #3: This report supersedes any earlier reports of this event.
This event has been reviewed by a seismologist.

A major earthquake occurred at 3:40:41 PM (PDT) on Sunday, April 4, 2010.
The magnitude 7.2 event occurred 26 km (16 miles) SW of Guadalupe Victoria, Baja California, Mexico.
The hypocentral depth is 10 km ( 6 miles).

Magnitude	7.2 - regional moment magnitude (Mw)
Time	Sunday, April 4, 2010 at 3:40:41 PM (PDT) Sunday, April 4, 2010 at 22:40:41 (UTC)
Distance from	Guadalupe Victoria, Baja California, Mexico - 26 km (16 miles) SW (225 degrees) Mexicali, Baja California, Mexico - 60 km (37 miles) SSE (165 degrees) Calexico, CA - 64 km (40 miles) SSE (163 degrees) San Luis, AZ - 65 km (40 miles) SW (231 degrees) Tijuana, Baja California, Mexico - 167 km (104 miles) ESE (105 degrees)
Coordinates	32 deg. 7.7 min. N (32.128N), 115 deg. 18.2 min. W (115.303W)
Depth	10 km (6.2 miles)
Location Quality	unknown
Location Quality Parameters	Nst=315, Nph=315, Dmin=112.1 km, Rmss=0 sec, Erho=0 km, Erzz=0 km, Gp=79.2 degrees
Event ID#	ci14607652
Additional Information	map with fault names Google Earth KML (Requires Google Earth.) Did you feel it? ShakeMap shaking intensity maps Waveforms SCSN Moment Tensor Solution Tsunami Information Statement from the WC/ATWC

Shake/intensity map:

The magnitude 8 earthquake that did not happen

2010-04-04T11:32:00.004-04:00

Yesterday, I got the following messages from the QUAKE-L listserv:

First
Date: Sat, 3 Apr 2010 00:45:46 +0000 (UTC)
From: ens@usgs.gov (USGS ENS)

PRELIMINARY EARTHQUAKE REPORT

Region: NORTH ATLANTIC OCEAN
Geographic coordinates: 19.053N, 68.052W
Magnitude: 8.0 M
Depth: 13 km
Universal Time (UTC): 2 Apr 2010 05:38:55
Time near the Epicenter: 2 Apr 2010 01:38:55
Local standard time in your area: 2 Apr 2010 05:38:55

Second
Date: Sat, 3 Apr 2010 01:16:57 +0000 (GMT)
From: ens@usgs.gov (USGS ENS)

DELETED: Event DR 2

== EVENT DELETED NOTIFICATION ==

***This event has been deleted after review by a seismologist.***

Geographic coordinates: 19.053N, 68.052W
Magnitude: 8.0
Universal Time (UTC): 2 Apr 2010 05:38:55
Time near the Epicenter: 2 Apr 2010 01:38:55

And here is the explanation:

Users of the USGS Earthquake Notification System received a message reporting a magnitude 8.0 earthquake near the Dominican Republic. This was a mistake. In an effort to increase our ability to detect smaller earthquakes in the Caribbean region following the January 12th earthquake in Haiti, the USGS began accepting earthquake locations and magnitudes from additional sources in the region. The message reporting a magnitude 8.0 earthquake near the Dominican Republic was incorrect and resulted in the distribution of the errant e-mail. We acknowledge this was a serious mistake and have issued a correction.

Temblor predicted for Los Angeles in 2.5 years

2010-04-01T15:50:00.006-04:00

Or, see the video here in YouTube.

Enjoy the beginning of April!