Taxonomy term

seismology

Human-induced earthquakes shake less

Occurrences of earthquakes in the Central and Eastern United States have increased since 2009 — a phenomenon that many scientists attribute to the growing use of hydraulic fracturing for fossil fuel extraction. Most agree that it’s not the fracturing itself, but the reinjection of wastewater into wells for containment beneath the surface that tends to induce seismic activity. Now, new research looking at the effects of induced seismic activity suggests that human-made earthquakes and naturally occurring tectonic earthquakes are felt differently at the surface.

21 Aug 2014

Are slow-slip earthquakes under Tokyo stressing faults?

More than 13 million people live in Tokyo, a city that has been devastated by earthquakes in the past and is likely to be rocked again. Since the massive magnitude-9 Tohoku earthquake and tsunami in March 2011, recurrence intervals for nondamaging slow-slip quakes beneath Japan's capital have shortened. And that has left seismologists to wonder if this aseismic creep could be signaling a countdown to Tokyo's next "big one."

07 Aug 2014

Books: The once and future San Andreas Fault

One of the most famous pictures of the San Andreas Fault — taken by G.K. Gilbert, the pioneering geologist whose late-19th century insights into faults and the earthquake cycle were close to prescient — shows a woman standing next to the ruptured fault immediately after the 1906 earthquake.

27 Jul 2014

Unlocking the Cascadia Subduction Zone's secrets: Peering into recent research and findings

Megathrust earthquake hazards drive much of the research into the 1,000-kilometer-long Cascadia Subduction Zone, which lurks off the coast of California, Oregon, Washington and British Columbia. New studies are helping elucidate what is happening off the Pacific Northwest coast.

20 Jul 2014

Longmenshan fault zone in the spotlight after two major quakes in five years

In May 2008, a magnitude-7.9 earthquake struck near Wenchuan, China, killing more than 80,000 people in the country’s biggest quake since 1950. Then, in April 2013, the magnitude-6.6 Lushan earthquake hit just 90 kilometers to the south — also within China’s Longmenshan Fault Zone, which separates the Tibetan Plateau to the west from the Sichuan Basin to the east — and caused another 200 deaths. Now, scientists have found that a roughly 60-kilometer segment of the fault zone between the epicenters of the two big temblors could be the next to rupture, although no one knows when or how big it might be.

05 Jun 2014

Precise to a fault: How GPS revolutionized seismic research

Conceived in the 1960s to provide precise time and position for the U.S. military, GPS was soon embraced by geodesists and earth scientists. Today, it is an essential tool for geoscience research that extends far below — and above — Earth's surface.

30 Apr 2014

A truly global system

Like the GPS navigation system in your car or smartphone, a high-precision GPS receiver uses signals from satellites to determine the distance from the receiver to the satellite. But that’s where the similarities end. 

30 Apr 2014

Observing a plate boundary

The U.S. Plate Boundary Observatory (PBO), a component of EarthScope, includes more than a thousand continuous GPS stations arrayed across the western United States and Alaska. 

30 Apr 2014

Faking quakes at full scale: Giant shake tables simulate earthquakes to make buildings safer

At a few select facilites around the world, engineers are able to shake full-size buildings to learn how to make them safer during earthquakes. Take a look at the massive shake tables that make it possible.

23 Apr 2014

Giant quake sloshed fjords half a world away

On the morning of March 11, 2011, Leif Hus and his wife Gry Melas Hus were having breakfast in their kitchen overlooking Sognefjord in Leikanger, Norway. It was low tide on a calm and windless day with near-freezing temperatures. As they stood, coffee cups in hand, looking out the window at the fjord, they saw an unusual wave roll in. The wave continued to rise, surging over the seawall into their backyard before receding back into the fjord. Then another wave surged in, and another. As the water rose, engulfing the ladder on their dock, Leif grabbed his cell phone and started filming.

02 Dec 2013

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