Changes in elements and magnetic properties of <scp>Sendai Bay</scp> sediments caused by the 2011 <scp>Tohoku‐oki</scp> tsunami
Changes in elements and magnetic properties of <scp>Sendai Bay</scp> sediments caused by the 2011 <scp>Tohoku‐oki</scp> tsunami
复制标题
2011 年 <scp>东北冲</scp> 海啸引起的<scp>仙台湾</scp>沉积物元素和磁性变化
DOI：
10.1111/iar.12437
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发表时间：
2022
期刊：
影响因子：
1.5
通讯作者：
Kogiso Tetsu
中科院分区：
文献类型：
--
作者：
Abe Hirokuni;Kawamura Noriko;Ishikawa Naoto;Kogiso Tetsu
沿着沿着岛弧沉积的近岸海洋沉积物可以保存过去灾难事件（如海啸）的证据。2011年3月11日发生在日本东北太平洋沿岸的海啸的证据可能保存在海洋沉积物中。利用地球化学和岩石磁性分析，本研究旨在调查保存在仙台湾海洋沉积物中的海啸记录，位于2011年东北地震震中以西。从2002年到2014年，我们在仙台湾的五个站（S-1，S-2，S-3，S-4和S-5）收集了沉积物样品。我们比较了海啸前后收集的样本。我们确定，在2011年的沉积物样本中，S-3、S-4和S-5站的粉砂成分增加，而细砂成分减少。值得注意的是，浓度的陆地和工业金属元素（铜，锌，铅）和总氮，碳，硫量增加，而磁化率和等温剩磁值减少后，海啸。我们还发现，2011年样品中贫钛磁铁矿增加，表明海啸介导的变化。研究区域在海啸发生6个月后经历了一场大台风，导致洪水泛滥。2012年样本中总有机碳和总氮比例的升高表明，陆地有机质是由洪水提供的。
Nearshore marine sediments deposited along island arcs can preserve evidence of past disaster events, such as tsunamis. Evidence of a tsunami that occurred off the Pacific coast of Tohoku, Japan, on March 11, 2011, was likely preserved in marine sediments. Using geochemical and rock magnetic analyses, this study aimed to investigate tsunami records preserved in marine sediments in Sendai Bay, located west of the epicenter of the 2011 Tohoku earthquake. We collected sediment samples at five stations (S‐1, S‐2, S‐3, S‐4, and S‐5) in Sendai Bay from 2002 to 2014. We compared the samples collected before and after the tsunami. We established that the silt component increased, while that of fine sand decreased at stations S‐3, S‐4, and S‐5 in the 2011 sediment sample. Notably, the concentrations of terrestrial and industrial metallic elements (Cu, Zn, and Pb) and total nitrogen, carbon, and sulfur amounts increased, while the magnetic susceptibility and isothermal remanent magnetization values decreased after the tsunami. We also found that Ti‐poor magnetite increased in the 2011 samples, indicating tsunami‐mediated changes. The study area experienced a large typhoon 6 months after the tsunami, leading to flooding. The elevation in the total organic carbon and total nitrogen ratio in the 2012 sample suggested that terrestrial organic matter was supplied by the flood.