Taxonomy term

fault

Buried sands tell of tsunami hazard from creeping megathrust fault

A slow-moving portion of the Alaska-Aleutian Mega­thrust Fault near Alaska’s Dutch Harbor appears more capable of generating sizable tsunamis than previously thought, according to a new study.

20 May 2016

The most dangerous fault in America

Running through densely populated cities like Oakland, Fremont and Berkeley, Calif., and not far from San Francisco, San Jose and Silicon Valley is a dangerous fault that could rupture at any time. It’s known as the Hayward Fault, and when it goes, it will likely produce a devastating earthquake.

18 May 2016

Downgoing plate topography stopped 2005 Sumatra rupture

In late March 2005, a magnitude-8.7 earthquake struck off the northwest coast of Sumatra, Indonesia, rupturing a portion of the Sunda Megathrust Fault and further terrorizing a region still reeling from the devastating 2004 Boxing Day earthquake and tsunami just three months prior. The March quake, however, could have been far larger than it was, according to new research. Scientists have identified a topographic barrier on the oceanic Indo-Australian Plate — which descends under the Sunda Plate in the Sumatra Subduction Zone — that may have stopped the 2005 rupture from propagating farther.

04 Apr 2016

Hidden double earthquake spells trouble for tsunami-warning systems

On Jan. 2, 2011, a magnitude-7.1 earthquake was recorded striking central Chile along the tectonic boundary between the Nazca and South American plates. Shaking from the quake was felt hundreds of kilometers from the epicenter, but no deaths or major damage were reported.
 
06 Mar 2016

Scarps and craters reveal moon's dynamic side

During their 1972 mission to the moon, Apollo 17 astronauts Eugene Cernan and Harrison Schmitt tried to ascend a steep rise in the lunar rover. The rover could not make it, so the pair drove up the incline in a zigzag pattern. The rise, it was later found, is the lobate scarp of a lunar thrust fault — one of many such features that, thanks to detailed images from NASA’s Lunar Reconnaissance Orbiter (LRO), are now known to occur across the moon’s surface. In a new study, researchers suggest these faults were formed by the same gravitational forces that cause the rise and fall of tides on Earth.

19 Feb 2016

Revealing potential tsunami inundation on California coast

Earthquakes are well known along Southern California’s coast, and existing hazard maps indicate where quake-triggered tsunamis could flood the coastline. But in a new modeling study published in Geophysical Research Letters, researchers found that an earthquake-generated tsunami northwest of Los Angeles may reach farther inland than is currently projected.
 
06 Feb 2016

Subducting seamounts blocked a big quake in Chile

Chile, which lies above a massive subduction zone fault, is one of the world’s most earthquake-prone countries, experiencing nine temblors of magnitude 7 or greater since 2010. In April 2014, a magnitude-8.1 earthquake struck 95 kilometers northwest of the city of Iquique, but despite its large size, the event failed to release all the stress thought to have built up along that portion of the fault. A new study reveals that a ridge of ancient underwater volcanoes may have blocked the 2014 earthquake rupture from propagating farther, thus limiting the size of the quake.
 

 

20 Jan 2016

Balanced boulders in earthquake country highlight interconnected faults

Precariously balanced boulders look like bizarre accidents in any landscape, but when they’re found in regions famous for frequent earthquakes, such gravity-defying formations are even more improbable. Scientists have long wondered about an odd collection of dozens of balanced boulders in the San Bernardino Mountains that seemingly should have been toppled centuries ago by the earthquakes that regularly shake Southern California. Even stranger, these car- to house-sized granite boulders are located within 10 kilometers of the active San Andreas and San Jacinto faults. Now, new detective work on 36 of the boulders is giving scientists clues about the connections between these faults. 
 
14 Dec 2015

Down to Earth With: Geophysicist Julian Lozos

Julian Lozos, a postdoctoral researcher affiliated with both the U.S. Geological Survey and Stanford University, designs computer models that simulate earthquakes. As a graduate student at the University of California at Riverside (UC Riverside), Lozos discovered part of what makes the San Jacinto Fault — a major fault in Southern California underlying the homes of millions — tick. For this work, Lozos received the Outstanding Student Presentation award at the annual meeting of the Seismological Society of America three years in a row, an unprecedented accomplishment.
 
29 Oct 2015

Source of Red Sea's mysterious cannon earthquakes revealed

For decades, people living along Egypt’s Red Sea coast have reported hearing loud blasts accompanying the small earthquakes that regularly jolt the Abu Dabbab region. And there is evidence the sounds have been occurring for much longer: Abu Dabbab means “the Father of Knock” in Arabic, hinting at a tectonic mystery at least as ancient as the name of the long-inhabited coastal region. Now, scientists are offering a novel explanation for the uniquely noisy seismic events, and their discovery is revealing new information about the underlying structure of the Red Sea region. 
 
08 Oct 2015

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