Taxonomy term

fault

Well-healed faults produce high-frequency earthquake waves

Much like our voices create sound waves with a variety of low and high pitches, or frequencies, earthquakes also produce seismic waves over a spectrum of frequencies. The seismic waves’ frequencies determine, in part, how far they travel and how damaging they are to human-made structures. But teasing out the details of how quake-generating faults influence seismic frequencies is no easy task, mainly because faults tend to be buried deep underground.

10 Mar 2013

Benchmarks: May 15, 1909: The Northern Great Plains earthquake

In Culbertson, Mont., at a quarter past nine on a Saturday evening, Ralph Bush and H.G. Walsh were resting in the third-floor apartment of the Reed Cash Grocery when the floor began to rock, vibrating a small penknife right off their table, and sending a candle lamp clattering to the floor. At the nearby Evans Hotel, confusion reigned as the quake shook the two-story brick building, causing frightened guests to flee into the streets. On the second story of the Farmers & Merchants bank, a piano player was entertaining a social gathering at the home of Professor Dale when the shaking sent a vase crashing to the floor. The 15 seconds of quivering was so pronounced at Skelley’s barbershop that, “It rang up a 50-cent cash sale on the cash register, and it has been keeping me guessing how I can balance the darned thing,” Skelley told a reporter from the Culbertson Republican.
 
02 May 2012

Hazardous Living: Collision forces behind devastating Turkey quake

By Tuesday evening local time, close to 500 people have been confirmed dead and more than 1,300 injured following a major magnitude-7.2 earthquake that struck eastern Turkey on Sunday at 1:41 p.m. local time. Countless people are still trapped under debris after the shallow quake, only 20 kilometers deep, leveled at least 2,260 buildings in Van, Ercis and other cities and villages, according to news reports.

25 Oct 2011

Large earthquake rocks Iran oil port

Wednesday, Sept. 10, 12:30 p.m. EDT — At 3:30 p.m. local time, a magnitude-6.0 earthquake struck Iran near the southern port city of Bandar Abbas. Tremors from the quake were felt as far away as the United Arab Emirates and Qatar, according to the U.S. Geological Survey.

USGS detected a magnitude-4.8 aftershock about 30 minutes after the quake, although John Bellini, a geophysicist at the National Earthquake Information Center in Golden, Colo., says that many other aftershocks have and will bypass U.S. detection.

10 Sep 2008

Creeping faults warn of impending earthquakes?

Earthquakes strike out of nowhere — one minute everything is perfectly calm, and the next minute, the ground shakes violently and buildings crumple. However, many seemingly sudden seismic events are actually preceded by a multitude of creeping changes underground. Detecting and interpreting these changes would help forecast earthquakes, but that detection has proven difficult, partly because scientists don’t yet fully understand the complex chain of events that precipitates a quake.

29 Aug 2008

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