Friday, November 27, 2009

Turkey and earthquakes

The North Anatolian Fault in Turkey bears many resemblances to the San Andreas Fault. Both are similar in length, and have motion that is horizontal and right lateral, which means as you look across the fault, the side opposite moves to the right. (Believe me, this is true regardless of which side you stand on.) And, both pass through major population centers, Istanbul being at risk from the NAF. Just another place in the world where plates are jostling up against one another.

 Source: USGS

The graphic below is very cool, integrating lots of information about the geography and historical movement on this fault.  Edward Tufte would be pleased.

The Istanbul area seems overdue for some slip!

The World Bank (a group whose development policies and choice of directors I don't always agree with) has a nice high quality video (along with a number of others) on its YouTube channel, about the seismic retrofitting of buildings in this historic city.


What, you thought this was going to be about Thanksgiving?

Sunday, November 22, 2009

Seismograph mashups of the future?

Researchers at Cal Tech enlist public to help them measure earthquakes `block-by-block'
By Emma Gallegos, Staff Writer
Whittier Daily News
Posted: 11/22/2009 06:02:20 AM PST

PASADENA - Researchers at Caltech who study earthquakes want to enlist Southern Californians with cell phones or computers to help them measure strong jolts in the region.

A couple of years ago, the researchers noticed that accelerators - small devices that measure motion - were becoming common, and now they're practically a standard part of Macintosh laptops and touch-screen cell phones.

That's when it clicked that the accelerometers might help them with their research.

"Lightbulbs went on in people's heads - there's seismometers all over the place," said Tom Heaton, director of the Earthquake Engineering Research Laboratory at Caltech.

This summer the group of professors and students received a grant from the National Science Foundation to create a program that could use the data from thousands - if not millions - of accelerometers to give seismic experts a better picture of earthquakes and the faults that cause them.

Right now there are about 200 high-quality seismic stations throughout Southern California. There's one at the U.S. Geological Survey on the Caltech campus, but the next one is in Glendale.

That doesn't cut it for researchers, who would like to be able to get a block-by-block portrait of what happens when an earthquake strikes but can't afford to pay the $15,000 it costs to pay for and maintain these seismic stations.

"Instead of a small number of high-quality instruments, we'd rather (have) a
larger number of lesser-quality instruments, trading quality for quantity," said Robert Clayton, a Caltech professor in the seismological lab.

The accelerometers could not only help measure quakes block by block but also floor by floor, said civil engineering Professor Monica Kohler. She's interested in the way the data could help civil engineers understand how buildings move and sway when a quake hits.

There are a couple buildings that have seismometers installed, but they tend to be costly and intrusive, she said.

"It's become obvious that this is a very easy way to start putting sensors and getting building motions up potentially every floor of a high-rise building," Kohler said.

The accelerometers aren't as sensitive as pricey seismic stations, but industry demands have brought the costs of some down to $50 to $100.

The researchers already have a working model that transforms the same technology that deploys air bags in cars and makes the Nintendo Wii remote possible to measure strong quakes.

The test accelerometers aren't much larger than a quarter, and they can attach to laptops via a USB port. When you bang on the table where these laptops are sitting, a red spot appears on a Google map showing the "epicenter" of the quake centered on the Caltech campus.

Of course, once thousands or millions of these devices are hooked up to a ShakeOut map, researchers say that this everyday jostling and knocking on a table won't register as an earthquake.

It's the simultaneous motion of these accelerometers that will signal that an earthquake has occurred. The group is working to make sure that this information moves quickly - transmitted via a wireless signal and then out of the system where it will be safe.

"What we'd like to do is to be able to take the earliest motions and get the information out of the region as fast as possible," Clayton said.

He calls this the "Indiana Jones effect." After the first wave of a major earthquake, the infrastructure of the city and electrical systems will begin to fail in a wave. That information needs to be able to move ahead of the first wave of the earthquake, like Indiana Jones in the "Temple of Doom."

The group is planning to slowly release distribute the devices to the community, beginning in 2010, Clayton said.

Caltech community members will be the first to test the accelerometers. By spring, the group plans to release the accelerometers into the local school system, tapping into science teachers, who could use them as teaching tools. Next summer, the group will distribute them to other school systems in Los Angeles and to fire stations.

And if all goes well on this project in Southern California, Clayton said that the research could be applied to other earthquake-prone areas - especially developing countries that suffer from strong earthquakes but have a weak system for sensing them. It would be as simple as distributing the sensors to local Internet cafes.

"If you could put one of these in every Internet cafe, you'd have an instant seismic network," Clayton said.

Friday, November 20, 2009

Educational seismographs for discounted sale

DTA, formerly a U.S. Sales and Service Center for Guralp Systems, a world leader in the design and manufacture of low-noise broadband seismometers, is now in the process of closing down, and has a few Educational Seismographs ("PEPP" and "EDU" instruments) in its inventory for sale.  These instruments are fully operational.  The instruments are listed below, along with their condition and price.  Because DTA is closing down, warranties cannot be provided.  If you are interested in purchasing any of these instruments, conatct Bruce Pauly. Quotations will be prepared upon request.  Delivery would be immediate from the shelf.  First come first served.

PEPP Style:

PEPP-V     V7207     USED     $2000     (25% off)

PEPP-V     V7209     USED     $2000     (25% off)       

PEPP-T     T6285     USED     $5000     (25% off)

PEPP-T     T6284     USED     $3000     (55% off)     (no GPS receiver)

PEPP-V     V7219    NEW       $2160      (20% off)

EDU Style:

EDU-V       V7320     NEW      $2295     (15% off)

EDU-T       T6827      NEW      $5950     (15% off)

Tuesday, November 17, 2009

How to blog: plagiarize

Not Dillsburg this time, but Dilbert.

In my opinion, this approach is ok if you attribute your sources.  Think of me as an aggregator.

Oh, btw, I still have my 33 1/3 and 45 rpm vinyl records.

Saturday, November 14, 2009

Shaking Earth after one year

Happy first anniversary, some time fairly recently.

I noticed we are now listed as one of 175 blogs on the geoblogosphere.

We're still the only seismology blog written by professional geophysicists(s) on a more than weekly basis.

And, 20,000 hits in the last year, even if half of those are probably me.

Carry on.

Thursday, November 5, 2009

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.

Monday, November 2, 2009

Seismograph widget for your Macintosh

A while back, I wrote about the Macintosh program Seismac that would use the sudden motion sensor in your computer (you know, in case you knock your Mac off the table, to stop the hard drive) to display a 3-axis accelerogram. It is a great teaching aid.

My IT colleague Teb not only relieved me of some candy this weekend (with his kids), but he told me that this capability is now available for Macs as a "widget" (a little snippet of software).

You can download it from Apple. Free, only 141k. 
System requirements - Mac OS X 10.4 or later; Macbook, Powerbook or iBook