Solid Data From Shaky Ground (Sound effect: earthquake sound)
I'm Bob Karson with the discovery files -- new advances in science and engineering from the National Science Foundation.
If there is such a thing as a positive after the magnitude-9 Japan earthquake, it is that it occurred on one of the most heavily-instrumented places on the planet -- with seismic measurement stations all over the place, (Sound effect: sound of seismic monitors) providing a virtual treasure trove of 'earth-shaking' information on the effects of a rare quake of this magnitude. Researchers at the Georgia Institute of Technology are sifting through this data, in the first study of how a shock this powerful affects the rock and soil beneath the surface.
The many high-quality seismometers record data both on the surface and from deep in the bedrock. By comparing the data, the team studied how the properties of the soil changed in response to the shaking. They found that the quake weakened subsurface soils by as much as 70 percent. Understanding soil response could help engineers design safer structures that could possibly stand up to the forces measured in this quake.
The team also looked at how fast soil strength recovers after an earthquake. That can range from a fraction of a second to several years.
If we are going to have safer structures -- I'm just glad someone's 'getting the dirt' on these big quakes.
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