Glacial earthquakes
Glacial earthquakes
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DOI：
10.1126/science.1088057
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发表时间：
2003-10-24
期刊：
影响因子：
56.9
通讯作者：
Abers, GA
中科院分区：
文献类型：
--
作者：
Ekström, G;Nettles, M;Abers, GA
我们已经在大冰川下探测到了数十次以前未知的中等地震。这些地震的地震辐射在高频率下被耗尽，这解释了传统方法无法检测到它们的原因。对阿拉斯加南部记录最好的地震的长周期地震波形的逆模拟表明，震源很好地表现为冰川冰块的粘滑和下坡滑动。阿拉斯加地震的滑动持续时间为30至60秒，比类似震级的常规构造地震长15至30倍。
We have detected dozens of previously unknown, moderate earthquakes beneath large glaciers. The seismic radiation from these earthquakes is depleted at high frequencies, explaining their nondetection by traditional methods. Inverse modeling of the long-period seismic waveforms from the best-recorded earthquake, in southern Alaska, shows that the seismic source is well represented by stick-slip, downhill sliding of a glacial ice mass. The duration of sliding in the Alaska earthquake is 30 to 60 seconds, about 15 to 30 times longer than for a regular tectonic earthquake of similar magnitude.