Time and size of a giant earthquake in Cascadia inferred from Japanese tsunami records of January 1700
Time and size of a giant earthquake in Cascadia inferred from Japanese tsunami records of January 1700
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DOI：
10.1038/379246a0
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发表时间：
1996-01
期刊：
影响因子：
64.8
通讯作者：
K. Satake;K. Shimazaki;Y. Tsuji;Kazue Ueda
中科院分区：
文献类型：
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作者：
K. Satake;K. Shimazaki;Y. Tsuji;Kazue Ueda
地质证据表明，在最近的史前时期，在北美太平洋沿岸的卡斯卡迪亚俯冲带发生过大地震。最近的事件（或一系列事件）发生在大约300年前1 -4，但确切的日期和震级尚未确定。地质调查还不能区分一个单一的大地震和一系列的大地震发生在一个十年或二十年的时间跨度4，虽然这一信息是重要的评估未来的灾害5。我们在日本发现了公元1700年以来的几次海啸记录，没有任何地方原因的迹象。历史地震记录和古地震证据表明，1700年在南美洲，阿拉斯加或堪察加半岛没有发生大地震，卡斯卡迪亚是这次海啸最有可能的来源。地震发生的时间估计为1700年1月26日晚上（当地时间21时左右）。从海啸高度估计震级为9级，在这种情况下，地震破坏了卡斯卡迪亚俯冲带的整个长度2。这些估计与美洲原住民关于冬夜发生地震的传说一致。
GEOLOGICAL evidence shows that great earthquakes have occurred in the recent prehistoric past in the Cascadia subduction zone, off the Pacific coast of North America. The most recent event (or series of events) is dated at about 300 years ago1–4, but the precise date and magnitude have not been determined. Geological investigations have not been able to distinguish a single giant earthquake from a series of great earthquakes occurring over a timespan of a decade or two4, although this information is important for the assessment of future hazard5. We have found several tsunami records in Japan from AD 1700 with no indication of a local cause. Historical earthquake records and palaeoseismic evidence indicate the absence of a large earthquake in 1700 in South America, Alaska or Kamchatka, leaving Cascadia as the most likely source of this tsunami. The estimated time of the earthquake is the evening (about 21:00 local time) of 26 January 1700. The magnitude is estimated as 9 from the tsunami heights, in which case the earthquake ruptured the entire length of the Cascadia subduction zone2. These estimates are consistent with Native American legends that an earthquake occurred on a winter night6.