Sequence of strong intraplate earthquakes in the Kodiak Island Region, Alaska in 1999–2001
Sequence of strong intraplate earthquakes in the Kodiak Island Region, Alaska in 1999–2001
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DOI：
10.1029/2001gl013416
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发表时间：
2001-10
影响因子：
5.2
通讯作者：
N. Ratchkovski;R. Hansen
中科院分区：
文献类型：
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作者：
N. Ratchkovski;R. Hansen
1999年至2001年，阿拉斯加-阿留申俯冲带科迪亚克岛地区发生了一系列强烈地震。1999年12月和2001年1月发生了两次7级地震，2000年7月发生了一次6.5级地震。区域地震仪网络记录的这些事件及其余震使用联合震源确定方法进行了重新定位。利用区域宽带数据获得了主震及其最大余震的地震矩张量。重新定位和矩张量反演结果表明，这些事件起源于俯冲太平洋板块内部。震源机制显示下倾拉张，断层面与俯冲板块走向基本垂直，平行于俯冲板块走向。1999年和2000年的事件位于巨型逆冲的锁定部分的向下倾斜，而2001年的事件位于它的正下方。
A sequence of strong earthquakes was registered in 1999–2001 in the Kodiak Island region of the Alaska‐Aleutian subduction zone. Two Mw 7 earthquakes occurred in December, 1999 and January, 2001 and an Mw 6.5 event occurred in July, 2000. These events and their aftershocks recorded by the regional seismograph network were relocated using a Joint Hypocenter Determination (JHD) method. Regional broadband data were used to obtain seismic moment tensors for the main shocks and their largest aftershocks. Relocation and moment tensor inversion results indicate that these events originated inside the subducting Pacific plate. The focal mechanisms indicate down‐dip tension with the fault planes being nearly vertical and parallel to the strike direction of the subducting plate. The 1999 and 2000 events were located down‐dip of the locked portion of the megathrust, while the 2001 event was located directly beneath it.