Earthquake Early Warning Network on EARTH Magazine

Initial earthquake behavior does not predict outcome

Thu, 19 Jan 2017 13:48:43 -0500

Example of early warning issued by ShakeAlert. Credit: Public Domain.

Can seismologists tell from the first few seconds of recorded seismic data how big an earthquake is going to be, or does it take longer and require data that come in after a quake rupture has progressed along the fault? The answer to this question underpins the usefulness of earthquake early warning systems and has perplexed scientists for decades. In a new study, researchers looking at near-source seismic recordings from shallow crustal earthquakes have found that, within the first few seconds of rupture, large and small earthquakes appear indistinguishable from one another, hinting that initial rupture behavior may be universal among variously sized events.

Vital seconds: The journey toward earthquake early warning for all

Thu, 03 Sep 2015 13:38:52 -0400

A mock-up of an earthquake early warning (EEW) alert on a cellphone. An EEW system is under development but not yet available to the public. Credit: K. Cantner, AGI, after Jennifer Strauss.

A ShakeAlert message like this would alert users to how many seconds they have before shaking waves arrive at their location and to the expected intensity of shaking. A shaking intensity of VI, as shown here, would mean the shaking would be strongly felt, people would find it difficult to stand, and structures could suffer damage. The warning message also displays a map with the location of the epicenter, the magnitude of the quake, and the current position of the P and S waves. Credit: USGS.

It is a cool foggy morning in San Mateo, Calif. A small ray of light has just peeked through my window. I listen to the birds chirping as I relish the final moments before my alarm calls for the start of a new day. It’s 6:15 a.m. Fifteen more minutes of a sleeping child.

Hazardous Living: Collision forces behind devastating Turkey quake

Thu, 05 Jan 2012 06:41:58 -0500

The North Anatolian Fault breaks into a complicated network of fault branches under the Marmara Sea, where it passes just 20 kilometers south of Istanbul. The new quake did not occur on the North Anatolian Fault. Tobias Hergert

Megan Sever is managing editor of EARTH and writes the Hazardous Living blog. Jim Sever

By Tuesday evening local time, close to 500 people have been confirmed dead and more than 1,300 injured following a major magnitude-7.2 earthquake that struck eastern Turkey on Sunday at 1:41 p.m. local time. Countless people are still trapped under debris after the shallow quake, only 20 kilometers deep, leveled at least 2,260 buildings in Van, Ercis and other cities and villages, according to news reports. Now, freezing temperatures and the possibility of snow on Wednesday bring new dangers to trapped victims and the thousands of people who are displaced and living in cars, tents and outside. Meanwhile, aftershocks, some as large as magnitude 6.0, have continued to shake the region.