Taxonomy term

seismology

Faking quakes at full scale: Giant shake tables simulate earthquakes to make buildings safer

At a few select facilites around the world, engineers are able to shake full-size buildings to learn how to make them safer during earthquakes. Take a look at the massive shake tables that make it possible.

23 Apr 2014

Giant quake sloshed fjords half a world away

On the morning of March 11, 2011, Leif Hus and his wife Gry Melas Hus were having breakfast in their kitchen overlooking Sognefjord in Leikanger, Norway. It was low tide on a calm and windless day with near-freezing temperatures. As they stood, coffee cups in hand, looking out the window at the fjord, they saw an unusual wave roll in. The wave continued to rise, surging over the seawall into their backyard before receding back into the fjord. Then another wave surged in, and another. As the water rose, engulfing the ladder on their dock, Leif grabbed his cell phone and started filming.

02 Dec 2013

Old photos help scientists relocate 1906 San Francisco quake rupture point

Portola Valley, just south of San Francisco, is famous for its progressive approach to geology. The town was the subject of the first geologic map of California and the first municipality in the state to hire its very own resident geologist. There’s a good reason: The section of the San Andreas Fault that produced the deadly San Francisco quake of 1906 runs right through the town. But where exactly the fault trace lies has long been a mystery. Now, in a new study, researchers have used a combination of new technology and old photographs to relocate the fault line.

25 Nov 2013

World's largest deep earthquake recorded

The seismology world may have a new leader in superlatives: On May 24, 2013, the largest, deep earthquake ever recorded struck beneath the Sea of Okhotsk, between the Kamchatka Peninsula and Russian mainland. Scientists are still puzzling over how such a large event could occur so deep.

30 Oct 2013

Big quakes topple traditional views of fault behavior

If rules are made to be broken, then perhaps conventional wisdom is made to be overturned. The spate of large earthquakes in recent years — the magnitude and location of which have defied scientific expectations in several cases — has provided ample support for these maxims, at least within earth science. For all the confusion, though, data emerging from these events are reshaping and improving our understanding of how faults operate.

14 Apr 2013

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

Voices: Judged unfairly in L'Aquila - roles and responsibilities should have been considered

Earlier this week, an Italian judge summarily convicted seven participants in a meeting of the Italian Serious Risks Commission who evaluated the hazard posed by the L’Aquila earthquake swarm before the magnitude-6.3 earthquake on April 6, 2009, for the same offense and to the same penalty: six years in prison. Much has been written about this court decision, but the very different roles played by the seven defendants and their different expertise have not been discussed. Is there no difference among the roles of the “L’Aquila Seven” in the communication disaster?

26 Oct 2012

Hazardous Living: Italian seismologists tragically convicted of manslaughter

Today, six seismologists and one government official were convicted of manslaughter and sentenced to six years in prison. The seismologists and official had been on trial for not adequately warning the public about the danger of a potential earthquake prior to the L'Aquila earthquake in April 2009 that killed 309 people.

22 Oct 2012

Better warnings for the consequences of earthquakes: Bringing seismic hazard and risk assessments to policy

Although seismologists and engineers have generated a world map of seismic hazard, which shows the level of ground shaking not likely to be exceeded, the ground motions and death tolls of several recent large quakes have far exceeded expectations. It’s time to change the way we measure seismic hazard and seismic risk.

29 May 2012

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

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