Unusually large tsunamis frequent a currently creeping part of the Aleutian megathrust
Unusually large tsunamis frequent a currently creeping part of the Aleutian megathrust
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阿留申巨型逆冲断层目前正在蠕动的部分经常发生异常大的海啸
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
T. Hill
中科院分区：
文献类型：
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作者：
R. Witter;G. Carver;R. Briggs;G. Gelfenbaum;R. Koehler;S. La Selle;A. Bender;S. Engelhart;E. Hemphill;T. Hill
目前用于评估地震和海啸灾害的模型是不充分的蠕变主导俯冲巨型逆冲断层。在这里，我们报告了大海啸的地质证据，平均每300-340年发生一次，靠近1946年和1957年阿留申海啸的源头地区。这些地区形成了200多公里长的假定地震间隙，现代大地测量表明，巨型逆冲断层目前正在蠕动。在Sedanka岛，大海啸的证据包括六个覆盖着面向太平洋的低地的沙层，上升到平均海平面以上15米，含有海洋硅藻，帽阶地，邻近冲刷的证据，可以追溯到过去的1700年。最新的薄片和现代漂流日志发现，远达800米的内陆和>18米的海拔可能记录了1957年的海啸。以前未被认识的海啸源与目前沿着阿留申俯冲带这一部分沿着蠕动的巨型逆冲断层共存。
Current models used to assess earthquake and tsunami hazards are inadequate where creep dominates a subduction megathrust. Here we report geological evidence for large tsunamis, occurring on average every 300–340 years, near the source areas of the 1946 and 1957 Aleutian tsunamis. These areas bookend a postulated seismic gap over 200 km long where modern geodetic measurements indicate that the megathrust is currently creeping. At Sedanka Island, evidence for large tsunamis includes six sand sheets that blanket a lowland facing the Pacific Ocean, rise to 15 m above mean sea level, contain marine diatoms, cap terraces, adjoin evidence for scour, and date from the past 1700 years. The youngest sheet and modern drift logs found as far as 800 m inland and >18 m elevation likely record the 1957 tsunami. Previously unrecognized tsunami sources coexist with a presently creeping megathrust along this part of the Aleutian Subduction Zone.
影响因子：
18.3
作者：
Lorito, S.;Romano, F.;Piatanesi, A.
通讯作者：
Piatanesi, A.