Geological effects of tsunami on mid-ocean atoll islands: The Maldives before and after the Sumatran tsunami
Geological effects of tsunami on mid-ocean atoll islands: The Maldives before and after the Sumatran tsunami
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DOI：
10.1130/g21907.1
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发表时间：
2006-03-01
期刊：
影响因子：
5.8
通讯作者：
Aslam, M
中科院分区：
文献类型：
--
作者：
Kench, PS;McLean, RF;Aslam, M
低洼的珊瑚岛是脆弱的地貌，容易受到长期海平面上升和飓风和海啸等极端事件的影响。2004年12月26日的苏门答腊地震产生的海浪到达2500公里外的马尔代夫。根据海啸前和海啸后对马尔代夫13个无人居住岛屿的地形和平面形态调查，本文介绍了对海啸影响的观察结果。调查显示，没有严重的岛屿侵蚀，岛屿面积也没有显著减少。相反，海啸加剧了海岸线变化的可预测的季节性振荡，包括暴露的岛屿陡崖的局部退缩达6英寸，尖叉口背风沉积，以及通过0.3米厚的砂层过冲沉积的垂直岛屿建设，覆盖了17%的岛屿面积。这些结果对岛屿的稳定性有影响，表明地势低洼的珊瑚礁岛屿在物理上是坚固的，环礁岛屿发展的海啸地质特征是轻微的。
Low-lying coral islands are fragile landforms susceptible to long-term sea-level rise and extreme events, such as hurricanes and tsunamis. The Sumatran earthquake of 26 December 2004 generated waves that reached the Maldives 2500 km away. Observations of the effects of the tsunami are presented here, based on pre- and post-tsunami topographic and planform surveys of 13 uninhabited Maldivian islands. The surveys showed there was no substantial island erosion and no significant reduction in island area. Rather, the tsunami accentuated predictable seasonal oscillations in shoreline change, including localized retreat of exposed island scarps by up to 6 in, deposition of cuspate spits to leeward, and vertical island building through overwash deposition of sand sheets up to 0.3 m thick, covering up to 17% of island area. These results have implications for island stability indicating that low-lying reef islands are physically robust and the geological signature of tsunamis on atoll island development is minor.