Investigation on recurrence intervals of the Toukai earthquakes by using tsunami deposits in coastal marsh in the Shima Peninsula, Mie Prefecture, Central Japan

利用日本中部三重县志摩半岛沿海沼泽的海啸沉积物调查东海地震的复发间隔

• 批准号: 13440150
• 负责人: YOSHIKAWA Shusaku
• 金额: $ 5.44万
• 依托单位: Osaka City University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13440150/
• 关键词: Shima Peninsula; Toukai Earthquake; Tsunami deposit; Paleomagnetism; Micro Fossil; 14C; 炭素年代測定; 三重県志摩半島; 東海・東南海地震; AMS^<14>C年代測定; 沿岸湿地

Great interplate earthquakes have repeatedly occurred along the Nankai trough and caused tsunami damage along the Pacific coast. The coastal lowland areas in the Shima Peninsula have been often struck by the tsunami after the Toukal and Tonankai earthquakes. The non-disturbed sampling with the Geo-slicer was carried out at three sites in the coastal marsh in Osatsu, Toba City, in order to investigate its environmental change and the relation with the event deposits.The sediments mainly consist of unconsolidated silt and clay intercalated thin sand layers. The several layers in these sands have good horizontal continuity and similar lithology. These sand layers include fragments of shell and foraminifer and its base of these sand layers have evidence of erosion. Because the surrounding inland area of investigation site can not supply coarse grained crusts under the geomorphologic environments, these sand layers are considered to event deposits such as tsunami.Possible tsunami deposits (named OS-1 to OS-12) are found in Holocene marsh sediments and dated by the AMS ^<14>C method. We calculated that recurrence intervals of large tsunami are almost 300-500 years in this area.

南开海槽多次发生板间大地震，并在太平洋沿岸造成海啸破坏。在Toukal和Tonankai地震之后，岛岛沿海低地地区经常受到海啸的袭击。为了研究滨海沼泽的环境变化及其与事件沉积的关系，用地质切片机对滨海沼泽的3个地点进行了地质切片机的无扰采样。这些砂体中的几个层位横向连续性好，岩性相近。这些砂层包括贝壳和有孔虫的碎片，其底部有侵蚀的证据。由于调查地点周围的内陆地区在地貌环境下不能提供粗粒结壳，这些砂层被认为是海啸等事件沉积。在全新世沼泽沉积物中发现了可能的海啸沉积(命名为OS-1至OS-12)，并用AMS^&lt；14&gt；C方法确定了其年龄。我们计算出，该地区大海啸的复发间隔几乎为300-500年。

项目成果

廣瀬孝太郎, 後藤敏一, 吉川周作, 三田村宗樹 (他1名): "鳥羽市相差沿岸低湿地堆積物中の珪藻遺骸群集に記録された完新世の環境変遷 イベント堆積物に関連して"第11回環境地質学シンポジウム論文集. 327-332 (2001)

Kotaro Hirose、Toshikazu Goto、Shusaku Yoshikawa、Muneki Mitamura（以及其他 1 位）：“鸟羽市大萨海岸低沼泽沉积物中硅藻遗骸组合记录的全新世环境变化。与事件沉积物的记录有关。”第十一届环境地质研讨会。327-332（2001）

吉川周作, 岡橋久世, 三田村宗樹, 廣瀬孝太郎, 内山美恵子: "三重県鳥羽市相差の完新世イベント層序"環境地質シンポジウム講演論文集. 13. 377-382 (2003)

Shusaku Yoshikawa、Kuze Okahashi、Muneki Mitamura、Kotaro Hirose、Mieko Uchiyama：“三重县鸟羽市大津的全新世事件地层学”环境地质研讨会论文集 13. 377-382 (2003)。

Nuneki Mitamura, Hisayo Okahashi, Kotaro Hirose, Shusaku Yoshikawa, Mieko Uchiyama, Toshio Nakamura, Tsuyoshi Haraguchi: "Event deposit and 14C age preserved in coastal marsh in Osatsu, Toba, central Japan"The Proceedings of 11^<th> Symposium on Geo-Envir

Nuneki Mitamura、Hisayo Okahashi、Kotaro Hirose、Shusaku Yoshikawa、Mieko Uchiyama、Toshio Nakamura、Tsuyoshi Haraguchi：“日本中部鸟羽市大津沿海沼泽中保存的事件沉积物和 14C 年龄”第 11 届地质研讨会论文集

Moriaki Yasuhara, Hisayo Okahashi, Kotaro Hirose, Muneki Mitamura, Shusaku Yoshikawa, Mieko Uchiyama, Tsuyoshi Haraguchi: "Preliminary report on ostracode assemblages from event deposits in Holocene coastal marsh from event deposits in Holocene coastal ma

Moriaki Yasuhara、Hisayo Okahashi、Kotaro Hirose、Muneki Mitamura、Shusaku Yoshikawa、Mieko Uchiyama、Tsuyoshi Haraguchi：“全新世沿海沼泽事件沉积物中介形虫组合的初步报告

Hisayo Okahashi, Kazumi Akimoto, Muneki Mitamura, Kotaro Hirose, Moriaki Yauhara, Shusaku Yoshikawa: "Event deposits in coastal marsh in Osatsu, Toba City, Mie Prefecture, Japan"Gekkan-Chikyu. 24. 698-703 (2002)

Hisayo Okahashi、Kazumi Akimoto、Muneki Mitamura、Kotaro Hirose、Moriaki Yauhara、Shusaku Yoshikawa：“日本三重县鸟羽市大津沿海沼泽的事件沉积物”月刊地球。