TRACES OF TSUNAMI PRESERVED IN INTER-TIDAL LACUSTRINE AND MARSH DEPOSITS - SOME EXAMPLES FROM NORTHEAST JAPAN
TRACES OF TSUNAMI PRESERVED IN INTER-TIDAL LACUSTRINE AND MARSH DEPOSITS - SOME EXAMPLES FROM NORTHEAST JAPAN
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DOI：
10.1086/629488
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发表时间：
1991-03-01
影响因子：
1.8
通讯作者：
NAKAYA, S
中科院分区：
文献类型：
--
作者：
MINOURA, K;NAKAYA, S
1983年5月26日的日本海地震引发了大规模的海啸，席卷了日本东北部海岸，造成了相当大的损失。 海啸在海岸上造成了特殊的沉积过程。 根据海啸的水力尺度，人们认识到三种沉积过程，每种都留下了独特的沉积物。 预计此类矿床将保留在沉积序列中，保留显著的沉积相。 在沿海地区不同地点钻探的钻孔样本已经过检查，以探测古代海啸的痕迹。 样品的沉积学和地球化学研究表明，层状沉积物，类似于日本海地震海啸所形成的沉积物，在钻取的岩心中很常见。 这些沉积物的估计年龄与历史记录中记载的古代海啸的日期完全相同。 这些结果表明，海啸的入侵记录在海岸沉积序列。 通过对长钻孔岩芯的分析，我们得出结论，海底地震产生的大规模海啸已经侵入津轻和仙台平原的沿海地区，其间隔分别为250 - 400年和约800年。
The Japan Sea Earthquake of May 26, 1983 triggered a large-scale tsunami that surged over the coast of NE Japan and caused considerable damage. The tsunami resulted in peculiar sedimentary processes on the coast. Depending on the hydraulic scale of the tsunami, three kinds of sedimentary processes were recognized, each of which left unique deposits. Such deposits are expected to remain in sedimentary sequences, preserving remarkable sedimentary facies. Borehole samples drilled at different localities in coastal regions have been examined to detect traces of ancient tsunamis. Sedimentological and geochemical studies of the samples reveal that layered deposits, similar to those developed by the Tsunami of the Japan Sea Earthquake, are common in the drilled cores. Estimated ages of these deposits are exactly equivalent to the dates of ancient tsunamis documented in historical records. These results show that the invasion of tsunamis is recorded in coastal depositional sequences. From analyses of long borehole cores we conclude that large-scale tsunamis produced by submarine earthquakes have invaded the coastal regions of the Tsugaru and Sendai Plains at intervals of 250 to 400 yr and about 800 yr, respectively.