Taxonomy term

seismology

Seismometers eavesdrop on glacial outburst flood

On July 5, 2016, a previously dammed glacial moraine in Nepal burst, releasing 100,000 tons of water that barreled down the Sunkoshi River, destroying bridges, hydropower plants and roads in its path. The flood was so massive that ground shaking was felt throughout the river corridor and recorded by seismometers deployed in the wake of the April 2015 Ghorka earthquake.

22 Feb 2019

Sounding Out Earth's Hum

Scientists are working to isolate and identify the various sources and mechanisms, beyond earthquakes, that vibrate the solid earth. The search has led them offshore to investigate how wind and waves and the seafloor interact to produce a symphony of sound that humans can’t hear.

11 Feb 2019

Thirsty mantle: Subduction zones swallow more water than thought

For all the water stored in oceans, ice and other reservoirs at Earth’s surface, there’s likely even more in the planet’s interior, where it plays important roles in many geological processes, including the formation of magma and the lubrication of earthquake-producing fault zones. Uncovering just how much water is inside Earth — and the extent to which it moves back and forth between the surface and subsurface — has long been a challenge for scientists interested in understanding the planet’s water cycle. A new study peering beneath the Mariana Trench in the Western Pacific has revealed that some subduction zones might pull significantly more water into Earth’s interior than previously thought.

30 Jan 2019

New measurement shakes up earthquake estimates

As tectonic plates collide and sink in subduction zones, huge megathrust earthquakes can produce devastation above. Yet, there are many unknown factors that control how much energy is released in each earthquake. Now, a team of scientists has come up with a new model to help crack the complexity and nature of megathrust earthquakes using global historical records.

13 Sep 2018

Seismic waves are blind to water

Geoscientists use the seismic waves produced by earthquakes to image the internal structure of the planet. Some seismic waves travel through liquids, while others do not, which is how we know, for instance, that Earth has a solid inner core and a liquid outer core.

08 Aug 2018

Yellowstone's Mexican mantle plume

The volcanic activity at Yellowstone National Park is impressive, with thousands of active thermal features dotting a nearly 4,000-square-kilometer caldera. Scientists have long suspected that a massive mantle plume underlies the supervolcano. Now, new imaging has provided the clearest picture yet of the heat source that drives Yellowstone’s volcanism.

26 Jun 2018

Earth's "hum" heard at ocean bottom

Lapping waves or crashing surf may come to mind for most people when they imagine the sounds of the ocean. But the ocean has other voices as well, including one produced by interactions of waves with the seafloor along the continental slope. Unlike waves on the shoreline, this steady, low sound, or “hum,” is inaudible to the human ear and has even proven difficult to detect in recordings made by ocean bottom seismometers (OBS). But in a new study in Geophysical Research Letters, researchers analyzing OBS data have now clearly identified the hum for the first time, which may allow it to be used to develop a better picture of Earth’s interior structure.

04 Apr 2018

Measuring earthquakes using fiber-optic cables

Fiber-optic cables crisscross the world, ferrying digital data and enabling internet access and telecommunication. In a new study, published in Geophysical Research Letters, researchers tested whether fiber-optic cables can also be used to detect and measure earthquakes.

23 Mar 2018

New Zealand quake triggers two large slow-slip events

On Nov. 14, 2016, a magnitude-7.8 earthquake struck near Kaikoura on New Zealand’s South Island, setting off a cascade of fault ruptures in the region. Within hours, seismic waves from the quake triggered a two-week-long slow-slip event on a section of the Hikurangi Subduction Zone between 250 and 600 kilometers north of the initial epicenter, as well as ongoing slow slip on the Hikurangi beneath New Zealand’s capital, Wellington, according to a new study in Nature Geoscience. Thanks to New Zealand’s advanced seismic and tectonic monitoring networks, the event is one of the best-documented examples of an earthquake triggering slow slip on distant faults.

21 Dec 2017

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

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