Geological and seafloor investigations of the cause of partial submergence of Yokoshima Island, Nagasaki, Japan
Geological and seafloor investigations of the cause of partial submergence of Yokoshima Island, Nagasaki, Japan
复制标题
日本长崎横岛部分淹没原因的地质和海底调查
DOI：
10.1016/j.enggeo.2021.106108
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发表时间：
2021
影响因子：
7.4
通讯作者：
Watanabe Tatsuya
中科院分区：
文献类型：
--
作者：
Yamasaki Shintaro;Kamai Toshitaka;Watanabe Tatsuya
1950年至1980年间，横岛约有一半消失在东海之下。该岛距离长崎海岸约1公里，在19世纪末和20世纪初开采煤炭。我们分析了岛屿和周围海底的地质，以调查它是如何被淹没的。使用了两种低成本技术来观察水下结构：一种是在浅于5米的沃茨使用装有摄像机的商用无人驾驶飞机，另一种是在深于5米的沃茨使用为业余渔民设计的回声测深仪和侧扫声纳系统。我们表明，岛屿的部分淹没可以解释为沉降的结果。岛屿北部的沉积岩下沉和向北倾斜，可能是由于废弃的海底矿井坍塌造成的，在岛屿南部形成了一种伸展状态，导致岛屿南部形成陡峭的悬崖和坍塌。我们的研究还表明，低成本的商业技术可用于浅水区的快速科学调查。
Between 1950 and 1980, about half of Yokoshima Island disappeared beneath the East China Sea. The island lies about 1 km off the coast of Nagasaki and was mined for coal during the late 19th and early 20th centuries. We analyzed the geology of the island and surrounding seafloor to investigate how it became submerged. Two low-cost techniques were used to view underwater structures: a commercial drone fitted with a video camera in waters shallower than 5 m and an echo sounder and side-scan sonar system designed for amateur fishers in waters deeper than 5 m. We showed that the partial submergence of the island could be interpreted as a result of subsidence. Subsidence and northward tilting of sedimentary rocks north of the island, probably caused by collapse of abandoned subsea mine workings, created an extensional regime south of the island that led to the formation of steep cliffs and collapse of the southern side of the island. Our study also shows that low-cost commercially available technology can be used for rapid scientific investigations in shallow water areas.