Taxonomy term

seismic

Earthquakes make volcanoes more — and less — gassy

Triggering of volcanic emissions by earthquakes has been observed since antiquity. The Roman naturalist and philosopher Pliny the Elder proposed the link as early as A.D. 77, and in “The Voyage of the Beagle,” Charles Darwin wrote about inland eruptions in Chile closely following an offshore earthquake in 1835. More recent statistical studies show that after large earthquakes, volcanic activity around the world increases. But the lack of robust monitoring equipment at most volcanoes has made it hard to quantify the relationship. In a new study, scientists demonstrate how satellites can be used to track changes in sulfur dioxide emissions from volcanoes after seismic events, offering a potential way to study the often elusive link between seismicity and volcanism.

25 Aug 2017

Seismic friction causes fault iridescence

Although iridescent spots on rocks in Utah’s Wasatch Fault Zone were first recognized two decades ago, scientists haven’t understood their origin, until now. New research shows that the iridescence appears on fault surfaces subjected to flash heating from friction and that the spots can provide clues to ancient seismic events. 

11 Nov 2014

Seismic citizens: Volunteers host home-based seismometers to help assess earthquake threat

A network of volunteer hosts and home-based seismometers around Washington’s Puget Sound region report earthquake data to the U.S. Geological Survey (USGS) and the Pacific Northwest Seismic Network (PNSN) through the volunteer-powered NetQuakes program. Driven by a desire to to help the area better prepare for future large earthquakes, to be part of a group effort, and by an abiding (though not necessarily professional) interest in science and technology, the members of this unusual family are part of a growing movement in earthquake research and monitoring that is making use of the explicit support of citizen scientists.

27 Aug 2012

Behind the scenes with NetQuakes' Doug Gibbons

Doug Gibbons, a research assistant in the University of Washington’s Department of Earth and Space Sciences and a NetQuakes technician, is one of several people involved in managing and maintaining the Pacific Northwest Seismic Network’s (PNSN) portion of the U.S. Geological Survey (USGS) NetQuakes program. Having installed many of PNSN’s NetQuakes seismometers, he is a point man for outreach and interaction with current and prospective volunteers.

27 Aug 2012

Japan's megaquake and killer tsunami: How did this happen?

On March 11, 2011, at 2:46 p.m. local time, a magnitude-9.0 earthquake ruptured a 500-kilometer-long fault zone off the northeast coast of Japan. Its epicenter was 130 kilometers off Sendai, Honshu; it occurred at a relatively shallow depth of 32 kilometers. The temblor violently shook northeast Honshu for six minutes, and collapsed its coastline by one meter.

17 May 2011

Don't forget about the Christchurch earthquake: Lessons learned from disaster

In the aftermath of the devastating magnitude-9.0 earthquake and tsunami that struck the Tohoku region of Japan on March 11, attention quickly turned away from a much smaller, but also highly destructive earthquake that struck the city of Christchurch, New Zealand, just a few weeks earlier, on Feb. 22.

17 May 2011

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

Glacier moves in fits and starts

The Whillans Ice Stream — an Antarctic glacier that covers an area slightly smaller than the state of New Jersey — flows from the interior of the continent to the ocean at a rate of about one meter per day. That’s not unusual for a large glacier, but how it covers that distance is surprising. Instead of inching along at a steady pace as most glaciers do, the Whillans Ice Stream jerks forward just twice a day, each time sending out seismic waves equivalent to a major earthquake.

28 Aug 2008