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

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.

Earthquakes in review for 2010 - USGS

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!

Earthquakes in Israel

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.

FAQ on earthquakes, California style

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.

Some earthquake statistics and graphs

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.

NPR - Are big quakes linked?

I have said previously that big quakes are not related, and that would still be my working hypothesis, but an NPR story (with text and audio) discusses this idea, and some related research. It also mentions, as I have, an aspect of random data (as earthquake occurrences may be): that events occurring at random times will not be evenly spaced in time, but occasionally either bunched up or further apart.

While on sabbatical in Munich, I now have the luxury of listening to NPR online, and if I listen to the archived shows (which I generally do because of the time difference), I can pick and choose the stories I want to hear. More or less this is good, but it does keep me from trying to better understand the German media, and allows me to fractionate the entire program that the NPR editors are presenting.  Still, better than my first sabbatical in Germany 20 years ago, at the dawn of email but really pre-www.  I had to struggle to understand German tv and newspapers, or spring for the pricey Herald Tribune once or twice a week, or go to the library to read it. Hey, come to think of it, that wasn't so bad, really.

Munich Re - Hazard Insurance

In my sabbatical city of Munich lies the headquarters of Munich Re. According to Wikipedia, Munich Re (Munich Reinsurance Company), a is the world’s largest reinsurer. In 2008 the company's equity amounted to $30 billion. The group’s premium income for the year (gross premiums written) was $6 billion, with its consolidated profit amounting to $2 billion. Big business!  One of the main offices is down the street from my apartment, and the commanding presence of the 50-foot tall Walking Man, by the American artist Jonathan Borofsky, is right out front on Leopoldstrasse.

Munich Re has some very good web pages on natural disasters.  It states its interest in earthquakes:

"Underwriting aspects - There are many areas with high concentrations of values and population that are also located in zones of very high seismic activity. In highly exposed areas with, at the same time, a high concentration of values and high insurance penetration, the insurance industry is confronted with a major problem: the possible accumulation of losses which include the risk of financial ruin. This makes it all the more important to gain an objective impression of the exposure. Only with this as a basis can the most appropriate prevention measures be implemented, be they realistic premium calculations, accumulation controls, and the establishment of reserves, or structural improvements and land-use restrictions."

Here is a table from Munich Re on the costliest hazards in recent years (pre-Haiti):

 

Yes, that's $125 billion for Katrina!  No wonder insurers are interested in natural disasters.

More from Munich Re to come.

U.S. Geological Survey and earthquakes in Afghanistan

An agreement between Afghanistan and the U.S. Agency for International Development and the USGS Policy Analysis and Science Assistance Branch (PASA) agreement was signed in September of 2004. This PASA initiated a USGS program in natural resources/hazards assessment for Afghanistan as part of the Afghanistan Reconstruction Program. The initial activities included coal, mineral and water resources assessments and earthquake hazard assessment. The U.S.Trade and Development Agency is also funding the USGS to conduct an oil and gas resources assessment of the country.

There are several hazards documents on the program webpage.  Included is a fact sheet on the earthquake hazard in Afghanistan.  It explains:

The nation of Afghanistan is located in a geologically active part of the world where the northward-moving Indian plate is colliding with southern part of the Eurasian plate at a rate of about 1.7 inches per year (43 mm/yr). This collision has created the world’s highest mountains and causes slips on major faults that generate large, often devastating earth- quakes. An example is the magnitude 7.6 earthquake on October 8, 2005, in Kashmir, Pakistan, which caused more than 80,000 fatalities and left an estimated 4 million people homeless.

Each year Afghanistan is struck by moderate to strong earthquakes, and every few years, a powerful earthquake causes significant damage or fatalities. As Afghanistan rebuilds following decades of war and strife, new construction and development need to be designed to accommodate the hazards posed by strong earthquakes. To assist in reconstruction efforts, the U.S. Geological Survey (USGS) has developed a preliminary seismic-hazard map of Afghanistan.

Click on the figure for a larger image.

As for the rest of the upcoming endeavors of the U.S. in Afghanistan, I tend to agree with Andrew Bacevich (see or listen to his interview on NPR, for example) that President Obama's decision to send more troops there is arbitrary and not well fitted to protecting us here at home, if indeed that is the goal.  The hope for quick success is ahistorical and based on faulty assumptions. But I guess those discussions should preoccupy other bloggers.

New edition of Earthquakes: Science and Society

Pearson Higher Education has published a new edition of David Brumbaugh's Earthquakes: Science and Society. The book has 272 pages, and the price is about $70 for the paperback edition.

According to Pearson, this text provides the basic scientific facts about earthquakes. It also explains how the study of earthquakes has progressed through time, offering details on the development of earthquake instruments, and covering practical aspects such as personal safety, building and living in areas prone to earthquakes, and earthquake geography.

The content is organized into three essentially independent sections:

• Part I provides a primer on earthquake basics, with a survey of the historical development of human thought on earthquakes, including early scientific ideas and myths, from Poseidon to elastic rebound.
• Part II considers how data gathered from earthquake instruments is used, and how the study of earthquakes has been applied to understand Earth.
• Part III focuses on personal safety and earthquakes, considering what can be learned from past earthquakes and offering a what–not–to–do handbook.

Senior seismologist olympics: earth shaking

I can only say this because, age-wise, I would qualify for the senior olympics!


"Charles K. Scharnberger, left, Helen Delano of the Bureau of Topographic and Geologic Survey and others jump to test a seismograph buried in the backyard of a Dillsburg area home on Friday. Over the years, residents of Moodus, Conn. have come to accept their earthquakes; in Dillsburg and Carroll Township, scientists and residents are still trying to figure out exactly what's happening." (Daily Record/Sunday News -- Jason Plotkin)

Latest small quakes in Dillsburg, PA

From LCSN:

A minor earthquake of magnitude 1.3 occurred in Dillsburg,
Pennsylvania (23 km southwest of Harrisburg, Pennsylvania).

There are felt reports from Dillsburg, PA.
There were a number of foreshocks and aftershocks reported.

Origin time: 5/11/2009 01:18:23.1 EDT
5/11/2009 05:18:23.1 UTC
Location: 40.088 N, 77.001 W Depth= 1 km fixed
(40 deg 5.3 minutes North, 77 deg 0.1 minutes West)
Magnitude: Mc=1.3

Only one aftershock was locatable:

Origin time: 5/11/2009 01:34:02.6 EDT
5/11/2009 05:34:02.6 UTC
Location: 40.099 N, 76.970 W Depth= 1 km
(40 deg 5.9 minutes North, 76 deg 58.2 minutes West)
Magnitude: Mc=1.2

Pennsylvania Disaster History

logo from http://www.readypa.org/

I was wondering the other day if Pennsylvania has a state equivalent of FEMA (Federal Emergency Management Agency). Yes, we do, and sure enough, it is PEMA (Pennsylvania Emergency Management Agency).

PEMA has a list of events comprising Pennsylvania Disaster History. Events are listed in chronological order, giving: date, general type of disaster, areas affected, and the response taken.

I re-classified the events somewhat, and came up with the following graph of the number of disasters, by type:

click on graph for larger version

Historically, earthquakes don't even make the list!

Based on this list, if you live in Pennsylvania, watch out for flooding and weather-related disasters, and fire. Of course, economic downturns are not listed.

Six months of south-central Pennsylvania seismicity

The figure and the list below are from the LCSN:

    Date        Time      Lat     Long   Depth Magnitude
year-mo-dy  hh:mm:sec    (N)     (W)    (km)  (Mc)
--------------------------------------------------
Lancaster County, PA
1972-12-08  03:00:32.5  40.150   76.220   4  0.0
1978-07-16  06:39:39.6  39.900   76.220   0  0.0
1984-04-19  04:54:55.1  39.946   76.323   7  2.9
1984-04-23  01:36:02.0  39.946   76.323   4  4.1
1984-04-23  02:46:00.5  39.946   76.323  10  2.5
1994-01-16  03:03:31.3  40.532   76.247   4  2.0
1995-03-11  21:10:16.0  40.100   76.400   5  2.7
1997-11-14  03:44:11.7  40.164   76.276   6  3.0
2000-03-22  20:48:00.0  40.070   76.300   1  1.8
2000-10-05  23:33:59.0  40.080   76.300   7  2.0
2001-07-17  14:41:20.2  39.937   76.340   1  1.8
2008-12-27  05:04:34.5  40.114   76.403   3  3.4

Adams County, PA
1994-05-26  17:21:58.2  39.950   77.187  11  2.8

Dillsburg, York County, PA

1997-06-16  05:43:16.6  40.098   76.967   5  1.9

2008 (21 events)
2008-10-05  22:36:48.1  40.054   76.967   2  2.0
2008-10-06  01:06:13.4  40.120   77.025   0  1.2
2008-10-06  06:15:38.4  40.069   76.992   0  1.1
2008-10-19  08:21:22.7  40.080   77.019   5  1.9
2008-10-19  08:22:07.3  40.078   76.963   5  2.1
2008-10-19  08:26:20.5  40.168   77.038   5  1.2
2008-10-19  08:28:09.0  40.087   76.998   5  1.5
2008-10-19  08:58:31.7  40.092   76.974   3  1.8
2008-10-19  09:06:01.5  40.091   77.018   5  1.0
2008-10-19  09:08:20.7  40.056   76.962   5  0.8
2008-10-19  09:08:44.3  40.092   76.987   5  1.1
2008-10-19  09:17:34.8  40.100   77.009   5  1.7
2008-10-19  09:49:19.1  40.095   77.002   5  1.0
2008-10-19  09:49:51.7  40.075   76.973   5  1.5
2008-10-19  09:50:11.4  40.091   76.989   5  1.6
2008-10-20  00:08:26.6  40.159   77.107   5  1.2
2008-10-20  00:14:03.9  40.075   77.005   5  1.1
2008-10-20  02:16:02.4  40.090   76.984   5  1.5
2008-10-23  15:55:32.3  40.068   76.962   5  1.2
2008-11-07  04:07:03.0  40.096   77.006   1  1.4
2008-12-31  05:34:08.8  40.107   77.003   1  2.1

2009 (3 events)
2009-04-22  13:21:14.1  40.073   77.002   1  1.1
2009-04-23  22:26:04.4  40.085   76.998   1  2.4
2009-04-24  05:36:48.8  40.064   77.026   1  2.9

See any patterns here? Maybe I'll try that next.

Happy Earth Day, 2009

from NASA

Today is the 39th anniversary of the first Earth Day, which I remember from when I was an undergraduate.

May we continue to use the Earth's burps to learn more about our planet, and minimize the dangers posed to our fellow inhabitants.

British seismotectonics

Good question posed in the comment after my last entry by Hypo-theses blogger Ian Simpson. Did St. Patrick chase the earthquakes out of Ireland? That would be a nice story indeed, but maybe we can come up with a scientific reason.

I won't claim to be an expert, but a Google search (shhh, don't tell my students) came up with a very nice PowerPoint from Dr. Brian Baptie of the Earthquake Seismology team, Earth Hazards and Systems Programme, British Geological Survey (excellent web site). The paper is on Seismo-tectonics and state of stress of the British Isles, presented at the 8^th International Symposium on Upper Rhine Graben Evolution and Neotectonics. You can find and download the presentation here.

Baptie does indeed note a strong variation in spatial distribution of seismicity throughout the United Kingdom. Earthquakes occur in a north-south band along the length of Britain. But there is an absence of seismicity in northeast Britain, the northwest Atlantic margin and Ireland (as we pointed out yesterday). The rather striking pattern is shown in the figure below.

The figure above (click on it for an enlarged version) shows historical seismicity of the UK (yellow) from 1832 to 1970 for earthquakes of magnitude above 3.0 and instrumental seismicity (red) from 1970 to present for earthquakes with magnitudes > 2.0 (from Earthquakes in the UK).

Baptie concludes that a prevailing stress field due to northwest compression is dominant, suggesting a combination of plate boundary forces plus post-glacial rebound may be controlling re-activation of old faults.

Earthquake-phobic? Go live in Ireland

According to the Irish Seismic Network:

"The largest recorded earthquake to have occurred in Ireland was a magnitude 2.3ML in Co. Leitrim in November 1994. There were no felt reports for this event.

"The largest recorded earthquake we have had offshore Ireland was a magnitude 5.4ML near the Welsh coast on 19 July 1984. This was felt mainly in Wales and adjacent parts of Britain, and over a significant area of the east coast of Ireland. There was some structural damage reported from North Wales adjacent to the epicentre of the event. More significant damage would have resulted had the event occurred at less than the estimated 20km depth."

Sounds pretty safe, earthquake-wise!

Happy St. Patrick's Day!

Who needs Twitter when you have Google earthquakes

Shaking up earthquake searches

from http://googleblog.blogspot.com/
3/05/2009 03:40:00 PM

Silicon Valley is well known as the home of technology companies like Google, but it's also one of many regions around the world with frequent earthquake activity. When we in the Bay Area feel an earthquake, we want to know how strong it was and where it occurred, as soon as possible. After all, even a small vibration could be the result of a severe earthquake far away. Traditionally, we've had to wait for answers as reporters scrambled to investigate and spread the news. But thanks to the US Geological Survey (USGS), we can get earthquake data straight from the source.

Now, when you search for "earthquakes" on Google, you'll get information on some of the most recent, significant earthquakes from around the world, right on the search results page. From there, you can click through to the USGS Earthquake Center for more information, or visit the epicenter of any quake on Google Maps. To find earthquakes closer to home, you can add a location to your query, for example: "earthquakes California."

Earthquake search is the latest of Google's special search features, and many others can help you in different ways. If you'd like to know the local time where an earthquake occurred, search for "time" followed by the location (for example, "time Japan"). Let's say the epicenter was 50km from the coast and you want to know how far that is in miles. Type "50km in miles" into the search box. You can find out about these special features and many more on the Search Features page.

What's shaking in Albany, NY?

Well, while I've been worrying about small earthquakes in Pennsylvania and New Jersey, you might have thought I'd forgotten about New York. Lo and behold, there have been seven small earthquakes near Albany in the last week. Belated fallout from the Eliot Spitzer affair? Who knows.

A list of the events from the LCSN web page is below. Each event is hot-linked to a more detailed report.

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

2.1  2009/02/23 10:46:20 42.574N 74.094W  7.0   19 mi SW
2.1  2009/02/21 02:30:43 42.569N 74.103W 11.0   20 mi SW
2.7  2009/02/20 13:04:19 42.572N 74.096W  8.0   19 mi SW
1.6  2009/02/19 09:22:58 42.573N 74.094W  8.0   19 mi SW
2.4  2009/02/18 11:20:23 42.572N 74.101W 10.0   20 mi SW
2.7  2009/02/17 22:41:50 42.570N 74.103W  9.0   20 mi SW
2.1  2009/02/17 09:33:26 42.571N 74.135W 16.0   21 mi SW

Here is part of a news account of one of these:

Earthquake triggers Gilboa dam inspection

Saturday, February 21, 2009

By Edward Munger Jr.
Gazette Reporter

SCHOHARIE — A small earthquake southeast of Albany Wednesday prompted an immediate inspection of the Gilboa Dam under new operating procedures put in place by the New York City Department of Environmental Protection, an engineer said Friday.

The earthquake was minor and didn’t cause any damage to the massive concrete structure that remains the focus of a multimillion-dollar construction project now in its first phase, said John H. Vickers, chief of western operations for the DEP.

According to the Lamont-Doherty Cooperative Seismographic Network, the magnitude 2.4 event took place at roughly 11:20 p.m. on Wednesday, centered roughly 32 miles southeast of Albany.

People in the vicinity of a magnitude 2.4 earthquake would feel minor shaking lasting two or three seconds, according to Won-Young Kim, senior research scientist at the Lamont-Doherty Earth Observatory of Columbia University in Palisades, NY.

The New York City DEP was notified and immediately dispatched inspectors to ensure there were no problems, as part of new standard operating procedure, Vickers said.

But I haven't seen any stories yet on the whole mini-swarm.

Here are the 5 New Jersey quakes

Thank you, commenter. Usually I am a good counter!  I had
to dig further at the New Jersey Geological Survey to get
the fifth event.

MAG  DATE  LOC TIME LAT  LON  DEPTH   LOCATION
    m/d   h:m:s    deg  deg   km

2.3 02/18 01:42:35 40.86 74.55  4.0 8 mi WSW of Boonton,NJ
1.4 02/16 14:38:31 40.94 74.02  7.0 7 mi NNE of Teterboro,NJ
1.1 02/16 13:17:55 40.96 74.38  2.0 4 mi NNE of Boonton,NJ
2.4 02/14 17:22:22 40.94 74.39  2.0 3 mi NNE of Boonton,NJ
3.0 02/02 22:34:19 40.87 74.52  5.0 6 mi WSW of Boonton,NJ

---

Five small New Jersey quakes in the last three weeks

Map of epicenters above, and list of events below, from the New Jersey Geological Survey.

1 km SSE of Dover, NJ on 2-18-2009, 1:42am (EST), Magnitude 2.3, Depth 4 km, Latitude 40.868 N and Longitude 74.551 W.

1 km ESE of Oradell, NJ on 2-16-2009, 2:38pm (EST), Magnitude 1.4, Depth 7 km, Latitude 40.948 N and Longitude 74.022 W.

3 km SSW of Kinnelon, NJ on 2-16-2009, 1:18pm (EST), Magnitude 1.1, Depth 2 km, Latitude 40.963 N and Longitude 74.389 W.

5 km NNE of Boonton, NJ on 2-14-2009, 5:22pm (EST), Magnitude 2.4, Depth 2 km, Latitude 40.948 N and Longitude 74.392 W.