Slip Distribution of the 1952 Kamchatka Great Earthquake Based on Near-Field Tsunami Deposits and Historical Records
Slip Distribution of the 1952 Kamchatka Great Earthquake Based on Near-Field Tsunami Deposits and Historical Records
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DOI：
10.1785/0120090376
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发表时间：
2010-08
影响因子：
3
通讯作者：
B. MacInnes;R. Weiss;J. Bourgeois;T. Pinegina
中科院分区：
文献类型：
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作者：
B. MacInnes;R. Weiss;J. Bourgeois;T. Pinegina
我们利用1952年堪察加海啸的约束条件，探索了1952年堪察加地震(MW8.8-9.0)的震级和滑动分布。我们新的实地数据提供了比迄今所能获得的更全面的近场海啸报道。我们研究了复杂地震破裂内的内部滑移分布对近场海啸抬高的影响，并评估了这种方法的一些局限性。我们的方法将海啸沉积物的分布与模拟的海啸抬高进行了比较，这些海啸是由与1952年堪察加地震相似的假想地震的海底变形的不同配置而产生的。由于海底形变的不同分布导致近场海啸抬升的不同，我们确定了高滑移区。绘制的沉积物图和对1952年堪察加海啸的当地观测表明，堪察加中部的近场抬升始终小于10米(平均为6米)，而南堪察加至千岛群岛北部的近场抬升变化更大，平均抬升更高(南堪察加8米抬高，千岛群岛北部10米抬升)。我们的模拟表明，为了产生海啸沉积和历史观测所指示的拉升分布，1952年地震在堪察加南部海岸附近有高滑移区，俯冲带的高滑移位置比先前解释的要浅。在线材料：沉积方法、模型输入和模拟结果。
We explore the magnitude and slip distribution of the 1952 Kamchatka earthquake (Mw 8.8-9.0) using constraints from the 1952 Kamchatka tsunami. Our new field data provide more comprehensive coverage of the near-field tsunami than had been available to date. We examine the effects of internal slip distribution within complex earthquake ruptures on near-field tsunami runup and evaluate some of the limitations of this approach. Our approach compares tsunami-deposit distribution with simulated runup from tsunamis generated by different configurations of seafloor deformation from hypothetical earthquakes resembling that of the 1952 Kamchatka earthquake. We identify areas of high slip because different distributions of seafloor deformation result in variations in tsunami runup in the near field. Mapped deposits and local observations of the 1952 Kamchatka tsunami indicate that near-field runup in central Kamchatka was consistently less than 10 m (averaging 6 m), while south Kamchatka to the northern Kuril Islands had more variability and higher average runup (8 m runup in South Kamchatka and 10 m runup in the northern Kuril Islands). Our simulations show that in order to produce the distribution of runup indicated by tsunami deposits and historical observations, the 1952 earthquake had regions of high slip off the coast of southern Kamchatka, and the location of high slip is shallower in the subduction zone than previously interpreted. Online Material: Sedimentary methodology, model inputs, and simulation results.