VOA常速英语:美国地质局推出先进的地震预警系统

Californians participated in an annual drill, and helped prepare for what scientists say could strike at any moment, an earthquake. Scientists have also been busy preparing. The US Geological Survey recently unveiled its new earthquake alert system called Shake Alert. Seismologists are calling the new system the most sophisticated in the world. I think we can say that the Shake Alert system is the most advanced early warning system in the world in the sense that not only does it recognize when an earthquake starts.

In the really big earthquakes, it starts to map out the finite extent of the fault. The Shake Alert 2.0 system was designed by the USGS and the UC Berkeley seismological laboratory to give early earthquake warnings to the millions of people who live in California, Washington and Oregon. Earthquake early warning is the effort to characterize an earthquake really really quickly after it starts. This earthquake started and it’s big, so drop cover and hold on. Shake Alert uses a network of sensors to tap into the seismic waves that course through the ground when an earthquake begins. So what you see over here on the side are the seismic equipment for the next seven earthquake early warning stations. A seismometer, this is the high-resolution, very sensitive instrument. This is an accelerometer. It can measure big earthquakes.
So we have sensors that are distributed across the surface, but then we have algorithms that recognize the shape of the fault disrupting, the actual area of rupture that’s slipping, and that’s what’s unique. None of the other systems have anything like that. Ideally, this new system will help people seek safety faster, vital and places where people live on earthquake faults.
Deana Mitchell for VOA news Berkeley, California.