Geomorphic imprints of repeated tsunami waves in a coastal valley in northeastern Japan.
Geomorphic imprints of repeated tsunami waves in a coastal valley in northeastern Japan.
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日本东北部沿海山谷反复海啸留下的地貌印记。
DOI：
10.1016/j.geomorph.2015.02.034
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发表时间：
2015
期刊：
影响因子：
3.9
通讯作者：
K.
中科院分区：
文献类型：
--
作者：
Hayakawa;Y.S.;Oguchi;T.;Saito;H.;Kobayashi;A.;Baker;V.R.;Pelletier;J.D.;McGuire;L.A.;Komatsu;G.;Goto;K.
2011年日本东北部太平洋沿岸地震引发的毁灭性海啸波严重淹没了日本东北部的岩岸沿着的山谷，导致山谷边坡基岩被侵蚀。利用地面和机载激光扫描获得的高分辨率地形数据，我们研究了在Aneyoshi的一个典型站点的侵蚀山谷的详细形态。我们发现了几个可能受海啸波侵蚀影响的特征：1）与海啸流深度相关的山谷边坡上的一系列小悬崖，2）向内生长的曲流弯曲处的边坡反向不对称，3）靠近海岸的异常宽的谷底，以及4）位于远离海岸的最大海啸上升点周围的断点。这些地形特征是由于中全新世以来反复的海啸波侵蚀。
Devastating tsunami waves induced by the 2011 off the Pacific coast of Tohoku Earthquake severely inundated valleys along the ria-type (notched rocky) coast in northeastern Japan, causing erosion of bedrock on valley-side slopes. Using high-resolution topographic data obtained by terrestrial and airborne laser scanning, we investigated detailed morphology of the eroded valley in a typical site at Aneyoshi. We found several characteristic features likely affected by tsunami wave erosion: 1) a series of small cliffs on the valley-side slopes related to the tsunami flow depth, 2) an inverse asymmetry of side slopes at ingrown meander bends, 3) an exceptionally wide valley bottom near the coast, and 4) a knickpoint located around the maximum tsunami run-up point far back from the coast. These topographic features are ascribable to repeated tsunami wave erosion since the mid-Holocene.