科学美国人60秒 SSS 2014-09-26
时间:2014-10-21 08:44:15
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(单词翻译)
Today's early warning systems for earthquakes give you at most a few minutes to prepare for the hit. That's because today's systems rely on detecting the first early rumbles1 of an actual earthquake before sending the alarm.
Now researchers say that following the chemistry of groundwater could sound a long-term quake alarm. They tracked samples from an artesian well in Iceland for five years and identified changes in the ratios of hydrogen
isotopes2 and a
spike3 in
sodium4 levels, four to six months before two 5+ magnitude quakes.
The chemical clues suggest mixing between groundwaters—so the researchers deduce that rocks may be fracturing, linking up underground
aquifers5, before the quake. The results are in the journal Nature Geoscience.
Investigations6 like this one have been
plodding7 along for 40 years, and some studies—like one following the deadly Kobe quake in 1995—have found similar
correlations8. But study author Alasdair Skelton, a professor of geochemistry at Stockholm University, says the unpredictable study subject makes it tough to get funding, "because you can in no way guarantee a result. So I get three years of money but if there's no earthquake, there's no result."
And even if we do accumulate more results like this and researchers sound a six-month alarm, what next? "If we're gonna ever predict earthquakes, we want something sort of intermediate term. Not years, and not minutes or days. So weeks or months is probably the most useful time scale—but the sheer practicality of it, what you do about it, I'm thankful I'm not the person who has to resolve that." Judging by the way leaders have responded to scientists' warnings about another issue , we might still be left ducking under the nearest table.
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