Taxonomy term

seismology

Seismic patterns help forecast eruptions from quiet stratovolcanoes

Earth is home to more than 1,500 potentially eruptive volcanoes on land, each with a unique character and history. Predicting when and how a particular volcano may erupt is notoriously difficult, in large part because each eruption is unique. Recent work tracking pre-eruptive seismic behavior beneath two dozen reawakened volcanoes has revealed a distinctive pattern that seismologists may be able to use to assess when — and how violently — a rumbling volcano could blow its top.

24 Nov 2017

Imaging Iceland's volcanic roots

Home to more than 30 active volcanoes, Iceland is one of the most vigorous volcanic settings on Earth. A new look at the core-mantle boundary thousands of kilometers below the island is offering one of the most complete pictures yet of how Iceland’s volcanoes are fueled.

21 Nov 2017

Desktop seismology: How a maker-inspired device is changing seismic monitoring

The Raspberry Shake — a personal seismograph invented in 2016 and named after the computer that powers the instrument (the Raspberry Pi) — was intended for hobbyists. But the device’s usefulness quickly became apparent to a much wider audience, including scientists and educators around the world. 
16 Nov 2017

Small-scale factors influence mantle flow under the seafloor

In December 2011, scientists and technicians aboard the research vessel Marcus G. Langseth dropped several ocean-bottom seismometers into the deep Pacific more than 1,900 kilometers southeast of Hawaii to measure seismic activity and electrical conductivity to a depth of about 300 kilometers below the seafloor. Now, these measurements are providing new insights into how the mantle flows and deforms below the rigid tectonic plates that make up Earth’s surface.

22 Nov 2016

Firefighting gets a leg up from earthquake sensor networks

Seismic networks monitor ground motion in earthquake-prone regions like California and Nevada. Now, they may also help combat other natural hazards like wildfires, which are especially common in drought-stricken western states where parched landscapes create ideal conditions for fires to spread.

19 Aug 2016

Going with the flow: Mapping the mantle under the Cascadia Subduction Zone

The Cascadia Subduction Zone (CSZ), off the Pacific Northwest coast of the United States and Canada, is one of the world’s most mysterious — and potentially dangerous — earthquake zones. Eerily quiet since a massive magnitude-9 event in 1700, scientists have long warned that the 1,000-kilometer-long fault zone could produce another devastating earthquake and tsunami. Now, a new effort to map the fault zone’s tectonic environment, including the underlying mantle, is shedding light on some of the dynamic forces that may influence earthquakes in the region.

25 Mar 2016

How deep do the Alps go?

Continental crust was long thought to be too buoyant to subduct into the mantle, unlike denser oceanic crust, which descends into the mantle in many locations around the world. But the discovery of coesite — a type of silica formed at the extreme pressures present in subduction zones — in the Alps in 1984 challenged that long-held idea. Seismic evidence backing up claims that continental crust has indeed been subducted beneath the Alps has been scant, however, until now.
26 Jan 2016

Vital seconds: The journey toward earthquake early warning for all

People living along the U.S. West Coast are keenly aware that they live near faults that could quake at any moment. The good news is that earthquake early warning — providing warnings seconds to minutes before damaging seismic waves hit — is progressing from being just a good idea to reality. 
17 Sep 2015

Seismometers listen for falling rocks

Scores of natural rockfalls occur in California’s Yosemi­­te Valley every year, often with little or no advance warning, posing hazards to people and infrastructure. In 1980, for example, a fall near Yosemite Falls killed three people and injured 19. Efforts to record and document rockfalls are rudimentary, relying only on eyewitness accounts and after-the-fact observations of fresh talus piles, which means many events are likely going unreported. In a new study, however, researchers interested in whether there’s a better way to monitor these events propose that seismic and infrasound sensors can help keep tabs on the granite slabs dropping from Yosemite’s cliffs.
 
25 Aug 2015

Stalled slabs sometimes stopped by mineral strengthening

Subduction of tectonic plates into the mantle functions as an eons-long recycling system for Earth’s crust and lithosphere. But in some subduction zones, the downgoing slabs seem to get stuck at depths of about 1,000 kilometers, held up by some unseen barrier on their journey deeper into the lower mantle. Now, scientists propose that this barrier might be related to high-pressure-induced strengthening of minerals in the rocks surrounding subducting slabs at these depths.
09 Aug 2015

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