HAZARDS

hazards

Dating of landslides around Oso reveals recurring patterns

On March 22, 2014, after a period of heavy rain, a hillside near the town of Oso, Wash., collapsed, sending 7.6 million cubic meters of mud and debris across the North Fork of the Stillaguamish River, destroying a rural neighborhood and killing 43 people. The slide took Oso residents by surprise, but scientists say the event was not altogether unexpected, as evidence for dozens of past landslides can be found throughout the Stillaguamish River Valley. New research suggests that large slides have occurred in the Oso vicinity even more frequently than previously suspected.

07 Jun 2016

Surprise quake at Mount Fuji triggered by rising gases

On March 15, 2011, four days after the magnitude-9 Tohoku megathrust earthquake and tsunami struck Japan, a magnitude-5.9 earthquake shook the southern flank of Mount Fuji. Seismicity has been rare at the volcano since its last eruption in 1707, leading many researchers to suspect that the Fuji quake — which hit about 300 kilometers southwest of the megaquake — was remotely triggered by the Tohoku event. In a new study, scientists looking at the volcano’s underlying structure and plumbing have offered a potential mechanism for how Tohoku’s shaking could have touched off the Fuji earthquake: through rising gas-rich fluids released from the magma chamber beneath the volcano.

27 May 2016

Double trouble: Volcanic eruption leads to strong earthquake eight months later

In January 2002, Nyiragongo Volcano erupted in the Democratic Republic of the Congo, killing more than 100 people. Eight months later and 19 kilometers to the south, a magnitude-6.2 earthquake shook the Lake Kivu region, partially destroying the town of Kalehe. Now, scientists have determined that the two events were linked, and their results highlight a newly observed trigger for strong earthquakes near active volcanoes.

24 May 2016

Comment: Assessing the threat from massive rock slope failures in the Norwegian fjordlands

Records dating back to the Vikings describe large rock avalanches into Norwegian fjords that set off lethal displacement waves. Today, increased development and tourism are exacerbating the risk.

21 May 2016

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

Mesa Arch's 'hum' measured to track health of rock structure

For decades, structural engineers have listened to the tiny vibrations of buildings and bridges to detect internal damage or weakness. In recent years, geoscientists have begun employing this technique, called “structural health monitoring,” to discover the hidden inner workings of natural rock features. In a new study, researchers have applied this method for the first time to examine a rock arch — Utah’s famous Mesa Arch — to determine whether this delicate structure is stable or soon to collapse.

12 May 2016

Medieval earthquakes in Nepal may help reveal the region's tectonic future

The magnitude-7.8 Gorkha earthquake in Nepal in April 2015 triggered landslides and damage that killed more than 8,500 people and injured at least 20,000, including many in and around Pokhara, the country’s second largest city. In a new study, scientists have found evidence that the city — also a major center of tourism in Nepal — and its surroundings sit atop debris from several large medieval-age quakes, confirming that the recent temblor is only the latest in a region with a long history of major earthquakes.

21 Apr 2016

Crippling heat stress projected by midcentury in densely populated regions

Extreme heat is the world’s top weather-related killer. Exposure to extreme heat caused more than 7,800 fatalities in the U.S. from 1999 to 2009, according to a 2013 report by the U.S. Centers for Disease Control and Prevention. And a single heat wave last summer killed at least 2,300 people in India, according to NOAA.

05 Apr 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

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