Effect of the 2011 Tohoku Earthquake on deep-sea meiofaunal assemblages inhabiting the landward slope of the Japan Trench
Effect of the 2011 Tohoku Earthquake on deep-sea meiofaunal assemblages inhabiting the landward slope of the Japan Trench
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DOI：
10.1016/j.margeo.2014.05.004
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发表时间：
2014-12-01
期刊：
影响因子：
2.9
通讯作者：
Kojima, Shigeaki
中科院分区：
文献类型：
--
作者：
Kitahashi, Tomo;Jenkins, Robert G.;Kojima, Shigeaki
2011 年日本东北部宫城县三陆海域发生东北地震 4.5 个月和 1.5 年后，对栖息在日本海沟（水深 120-5600 m）向陆斜坡的小型动物群落进行了检查。对地震前（24-30 年）和地震后（2011 年 4.5 个月和 2012 年 1.5 年）两个关键参数进行了比较：(a) 测深模式和 (b) 沉积物中小型底栖动物的垂直分布。地震前后没有检测到小型动物密度和相关测深模式的差异。然而，沉积物中小型动物的垂直剖面在某些站点有所不同。一些站点的小型动物密度最高出现在 2011 年的地下层，但这些地下峰值在 2012 年不再出现。在这些站点，2011 年和 2012 年较高类群水平的组合结构有所不同，2012 年桡足类密度有所增加。因此，由于地震相关事件（例如地震引起的快速沉积）的影响，桡足类丰度似乎有所下降。浊度电流）。地震后检测到的小型动物垂直剖面和组合结构的这些变化可能是由于最表层有机质含量的增加造成的。这些结果表明，2011年东北地震后，深海沉积物的重大扰动主要影响了小型底栖动物的垂直分布和组合结构，而小型底栖动物密度在事件发生后4.5个月内保持相似或迅速恢复。 (C) 2014 Elsevier B.V. 保留所有权利。
Meiofaunal assemblages inhabiting the landward slope of the Japan Trench (water depth, 120-5600 m) were examined 4.5 months and 1.5 years after the 2011 Tohoku Earthquake off Sanriku, Miyagi Prefecture, northeast Japan. Two key parameters were compared before (24-30 years) and after (4.5 months in 2011 and 1.5 years in 2012) the earthquake: (a) the bathymetric pattern and (b) the vertical distribution of meiofauna in the sediments. Differences in meiofaunal densities and associated bathymetric patterns were not detected before and after the earthquake. However, the vertical profiles of meiofauna in the sediments differed at some stations. The highest meiofaunal densities occurred in the subsurface layers in 2011 at some stations, with these subsurface peaks being no longer present in 2012. At these stations, the assemblage structure at the higher taxon level differed between 2011 and 2012, with copepod density increasing in 2012. Therefore, copepod abundance appeared to decrease because of the effect of earthquake-related events (e.g. rapid sedimentation induced by the turbidity current). These changes in meiofaunal vertical profiles and assemblage structures detected after the earthquake were probably caused by an increase in organic matter content in the topmost layers. These results indicate that major disturbances to deep-sea sediments mainly influenced the vertical distribution and assemblage structure of meiofauna after the 2011 Tohoku Earthquake, whereas meiofaunal densities remained similar or quickly recovered within 4.5 months of the event. (C) 2014 Elsevier B.V. All rights reserved.