Though less frequent, earthquakes on the East Coast can typically be felt over a much larger area than those with a similar magnitude on the West Coast. The bedrock in California, for example, is fractured, causing seismic waves that travel through it to dissipate faster. In the eastern half of the United States, the bedrock is less fractured and stronger, allowing earthquake energy to travel farther. (via NYTimes)
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Though less frequent, earthquakes on the East Coast can typically be felt over a much larger area than those with a similar magnitude on the West Coast. The bedrock in California, for example, is fractured, causing seismic waves that travel through it to dissipate faster. In the eastern half of the United States, the bedrock is less fractured and stronger, allowing earthquake energy to travel farther. (via NYTimes)

Fuente: The New York Times

Most natural hazard specialists believe the key to reducing losses is to use our existing knowledge of the ways earthquakes occur, and where, to implement measures that increase awareness, preparedness and resilience. The real focus needs to be on dealing with the social, political and economic barriers that prevent effective disaster risk reduction. While speculative research on prediction is an interesting exercise, and might yield unintended benefits, it is not the magic bullet that will reduce losses, no matter how appealing it might seem at first glance.
Dave Petley

Fuente: Guardian

Shishikura’s team took soil layer samples along the Tohoku coast and checked them against disaster accounts recorded in ancient chronicles. This helped them conclude that major temblors and tsunami repeatedly slam Tohoku over a cycle of between 500 and 1,000 years. Shishikura had planned to visit the Fukushima Prefectural Government last March 23 to explain this danger. Shishikura’s team even drew up maps of the areas flooded by the 869 tsunami and planned to distribute copies to residents along the coast. The maps turned out to be nearly identical to the areas that were inundated on March 11. “We could have saved some lives if the tsunami had come just a month later,” he lamented. (via The Japan Times Online)
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Shishikura’s team took soil layer samples along the Tohoku coast and checked them against disaster accounts recorded in ancient chronicles. This helped them conclude that major temblors and tsunami repeatedly slam Tohoku over a cycle of between 500 and 1,000 years. Shishikura had planned to visit the Fukushima Prefectural Government last March 23 to explain this danger. Shishikura’s team even drew up maps of the areas flooded by the 869 tsunami and planned to distribute copies to residents along the coast. The maps turned out to be nearly identical to the areas that were inundated on March 11. “We could have saved some lives if the tsunami had come just a month later,” he lamented. (via The Japan Times Online)

Fuente: japantimes.co.jp

acidadebranca: This map is a large format wall map of the geology of the 48 states, with an inset map showing California fault lines and major earthquakes. The map combines SHP and SDF features. USA state boundaries come from the Navteq datasets in SDF format that are included with AutoCAD Map 3D. SHP files for the geology and earthquake data were downloaded from the National Atlas (United States Department of the Interior). via
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acidadebranca:

This map is a large format wall map of the geology of the 48 states, with an inset map showing California fault lines and major earthquakes. The map combines SHP and SDF features. USA state boundaries come from the Navteq datasets in SDF format that are included with AutoCAD Map 3D. SHP files for the geology and earthquake data were downloaded from the National Atlas (United States Department of the Interior).

via

(vía fuckyeahcartography)

Fuente: acidadebranca

Earthquakes - Shock Waves (by USGS)

Source: http://gallery.usgs.gov/videos/438. This short excerpt is from a USGS/Bay Area Earthquake Alliance produced television program “Shock Waves: 100 Years After the 1906 Earthquake”. This specific segment describes some of the history behind our modern understanding of the earthquake process. The program received numerous industry awards and was nominated for a regional Emmy Award in the Bay area. It aired twice on KPIX CBS5 and its affiliate station around the time of the April 18, 2006, 100 year anniversary of the Great San Francisco Earthquake. The full program is streamed at the link:http://earthquake.usgs.gov/regional/nca/1906/shockwaves/

Fuente: youtube.com

QuakeCaster Trailer (por volkansevilgen)

QuakeCaster is an interactive, hands-on teaching model that simulates earthquakes and their interactions along a plate-boundary fault. QuakeCaster contains the minimum number of physical processes needed to demonstrate most observable earthquake features. This tool, which is designed so that students or audience members can operate it and record its output, enables people to test and explore hypotheses for earthquake occurrence.

Fuente: youtube.com

extremely loud & incredibly close

pasadenapictures:

9/11“     The collapse of the World Trade Center towers, nearly ten years ago, registered as minor earthquakes (with magnitudes of 2.2 and 2.4) on a seismometer locked in a former root cellar on the old Lamont estate, twenty miles upriver, in Palisades, New York.  A blown-up seismogram of the impacts from that morning now hangs on a wall of Thomas Lamont’s onetime swimming pool, which has been converted into a kind of seismological museum, beneath the cafeteria at Columbia’s Lamont-Doherty Earth Observatory.

Art Lerner-Lam, a seismologist and the interim director at Lamont-Doherty, was at a meeting in Morningside Heights last Tuesday afternoon, on the ground floor of a sturdy Depression-era limestone building.  He missed the tremors sent by a reverse faulting beneath the earth’s crust in Virginia which would soon overtake his week: the convulsions felt by city drivers idling at stoplights; the swaying of skyscrapers that sent thousands scurrying down flights of stairs, in a replay of the false alarms set off during the early aftermath of September 11th.  “There’s certainly a machismo that didn’t get satisfied here,” he said the next evening, after conducting a tour of the root cellar and the museum.

He’d had a long day of discussing local geologic features (the Ramapo Seismic zone, the 125th Street fault, the Peekskill-Stamford “trend”) and the disaster scenarios we might responsibly anticipate.  Earthquake expertise can be morally trying, with public validation tending to come only at moments of great suffering.  but this, it seemed was a rare win-win: a legitimate seismic event (magnitude 5.8) with relatively little human cost.  It was “a good earthquake,” as one of Lerner-Lam’s colleagues put it.  “Sort of guilt-free.” “ continue reading | The New Yorker

[title: Jonathan Safran Foer][image:source]

Five myths about earthquakes

by renowned seismologist Susan Hough:

  1. Animals sense impending earthquakes: “Every pet owner understands that, say, cats and dogs sometimes behave strangely for no apparent reason; that’s what cats and dogs do. And if an earthquake had not subsequently struck, you can bet we would not be talking about strange animal behavior this week — because we wouldn’t have noticed anything out of the ordinary.”
  2. The frequency of large-scale earthquakes has spiked: “The number of earthquakes greater than magnitude 7.0 has been somewhat high in recent years but well within the range throughout the 20th century.”
  3. Small earthquakes are helpful because they release pressure and prevent larger ones: “For each unit increase in magnitude (i.e., going from 5.5 to 6.5), the energy released rises by a factor of about 30. (…) If enough stress has built up on a fault to generate a magnitude-7.0 earthquake, say, it would thus take about 1000 earthquakes with a magnitude of 5.0 to release the equivalent energy. The Earth doesn’t work that way. (…) If there is significant strain energy to be released, it must be released in large earthquakes.”
  4. “Don’t worry, it was just an aftershock.”: “The implication is that an aftershock is somehow a less worrisome event. Yet, as far as we understand, an aftershock of a certain magnitude is no different from an independent temblor of a similar magnitude. The shaking and rupture are the same; the energy released is the same. And aftershocks can be more damaging than larger “mainshocks” if they strike closer to population centers.”
  5. Earthquakes are a West Coast problem: “As millions of people on the East Coast were just reminded, less active does not mean inactive. By the end of the 19th century, two of the most notable temblors in the United States were the 1886 quake in Charleston, S.C., and a sequence of large events centered near the boot-heel along the New Madrid Fault of Missouri in 1811-1812. We don’t know exactly when or where the next Big One will hit the United States, but the central and eastern United States will inevitably experience large quakes in the future. (…) You have been warned.”

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