Marine biomarkers deposited on coastal land by the 2011 Tohoku-oki tsunami
Marine biomarkers deposited on coastal land by the 2011 Tohoku-oki tsunami
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2011 年东北冲海啸在沿海土地上沉积的海洋生物标志物
DOI：
10.1007/s11069-015-1598-9
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
T.
中科院分区：
文献类型：
--
作者：
Shinozaki;T.;Fujino;S.;Ikehara;M.;Sawai;Y.;Tamura;T.;Goto;K.;Sugawara;D.;Abe;T.
为了确定海啸是如何以及什么样的海洋生物标志物被运输并沉积在陆地上，我们收集并分析了2011年日本东北部仙台和小坂海啸沉积物以及底层和上覆土壤的样本。特征碳氢化合物，如短链烷烃、硅烷和植烷，仅在两个地点海啸沉积物以下0-2厘米的土层中检测到。在小田沙上覆的泥层中检测到甲藻类的甲藻甾醇。在海啸沉积物下方2 cm以上的土层中没有检测到这些特征生物标志物，在大坂海啸沉积物上方的表层土壤中也没有发现这些特征生物标志物。因此，这些生物标志物很可能是在海啸的作用下被搬运和沉积的。砂层渗透性强，有机质含量低，可与生物标志物结合。任何与沙子一起沉积的生物标记物都可能被浸出到下面的土壤中，或者是在富含粘土和有机物的沉积物中发现的，比如海啸形成的泥浆。海啸发生2年多后采集的沉积物样本表明，海洋生物标志物在土壤中至少保存了2年。此外，对先前收集的沉积物样本的比较分析表明，海啸发生3个月后，特征生物标志物并未在沙层中保留。这些发现表明，利用生物标志物作为代用物来识别沿海陆地上的海洋沉积物是有潜力的。
To determine how and what kind of marine-sourced biomarkers are transported and deposited on land by tsunami, we collected and analyzed samples of the 2011 Tohoku-oki tsunami deposits and the underlying and overlying soil at Sendai and Odaka, in northeast Japan. Characteristic hydrocarbons, such as short-chainn-alkanes, pristane, and phytane, were detected only in soil layers 0–2 cm below the tsunami deposits at both sites. Dinosterol originated from dinoflagellates was detected in a mud layer overlying sand deposits in Odaka. Such characteristic biomarkers were not detected in soil layers deeper than 2 cm beneath the tsunami deposits at either site, and none was found in the surface soil layer overlying the tsunami deposit in Odaka. Therefore, it is probable that the biomarkers were transported and deposited by the tsunami. The sand layer was highly permeable and low in clay or organic matter to which biomarkers could bind. Any biomarkers deposited with the sand probably leached into the underlying soil or were found in sediments richer in clay and organic matter such as tsunamigenic mud. Sediment samples were collected more than 2 years after the tsunami, indicating that the marine-sourced biomarkers were preserved for at least 2 years in the soil. In addition, a comparative analysis of sediment samples collected earlier indicated that characteristic biomarkers did not remain in the sand layer 3 months after the tsunami. These findings show the potential of using biomarkers as proxies to identify marine-sourced deposits on coastal land.