Detecting trace of paleo-tsunami event from the bed form on the seafloor of a coastal shelf

2016 Fiscal Year Final Research Report

• Project/Area Number: 26350480
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Natural disaster / Disaster prevention science
• Research Institution: Hokkaido Research Organization
• Principal Investigator: NISHINA Kenji 地方独立行政法人北海道立総合研究機構, 環境・地質研究本部地質研究所, 研究主査 (40446373)
• Co-Investigator(Renkei-kenkyūsha): KASE Yoshihiro 北海道立総合研究機構, 環境・地質研究本部 地質研究所, 研究職員 (20707715) ; HAYASHI Keiichi 北海道立総合研究機構, 環境・地質研究本部 地質研究所, 研究職員 (30707906) ; SAGAYAMA Tsumoru 北海道立総合研究機構, 環境・地質研究本部 地質研究所, 専門研究員 (90446352) ; URABE Atsushi 新潟大学, 災害・復興科学研究センター, 准教授 (20281173) ; TAKASHIMIZU Yasuhiro 新潟大学, 教育学部, 准教授 (10446370)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 日本海東縁変動帯 / 数値シミュレーション / 陸棚 / サンドリッジ / 津波堆積物 / ベッドフォーム / 内部波 / 古海水準

Outline of Final Research Achievements

Numerical simulations of tsunamis from various wave sources and at various paleo-sea level settings were conducted. Taking into account the recent sea level at Ishikari Bay, the calculated tsunami wave-current velocity is on par with the measured current velocity, which is influenced by internal waves during storm events. Due to the low potential for tsunami traces to be generated and preserved, detecting these on the continental shelf of Ishikari Bay is difficult.
The results of the survey using numerical simulations of tsunami wave velocities in the south-eastern Japan Sea revealed the presence of a particular point on the shelf where a strong flow is generated by a wave with a specific source. The tsunami traces at that site may make it possible to constrain estimates of the source of the paleo tsunami wave.

Free Research Field

堆積学、沿岸海洋地質、