Exp. 405 JTRACK – Tracking Tsunamigenic Slip Across the Japan Trench
航海概要
| 航海名 | Expedition 405: JTRACK - Tracking Tsunamigenic Slip Across the Japan Trench |
| プロポーザル／ Scientific Prospectus | プロポーザル #835-Full2 Scientific Prospectus |
| 共同首席研究者 | Shuichi Kodaira, Marianne Conin, Patrick Fulton, Jamie Kirkpatrick, Christine Regalla and Kohtaro Ujiie |
| 掘削船 | D/V Chikyu |
| 航海予定期間 | 2024年9月6日〜12月20日（予定） |
| 乗船/下船地 | TBD |
| MarE3のページ | https://www.jamstec.go.jp/chikyu/j/exp405/ |
| 掘削地点 |  Location maps of the study area. A. Map showing the tectonic configuration at the Japan trench, the rupture area of the 2011 Tohoku-oki rupture (slip contours in white, after Iinuma et al., 2012), and the locations of existing IODP Site C0019 and DSDP site 436. EU/OK = Eurasian or Okhotsk Plate. PA = Pacific Plate B. Inset map showing major physiographic features of the Japan trench, the locations of proposed dill sites JTCT-01A and JTCT-02B. |
| 科学目的 | 本航海では、東北地方太平洋沖地震が発生した日本海溝にて、地球深部探査船「ちきゅう」による調査を行います。地震による摩擦熱を捉えた2012年のIODP Expedition 343 JFAST 調査域に再訪し、地震後の断層固着回復過程、プレート境界断層浅部のすべりメカニズム、沈み込み帯の物質特性がプレート境界断層に与える影響の解明に挑みます。そのため、大きなすべりが発生したプレート境界浅部(JTCT-01A) と沈み込む太平洋プレート上(JTCT-02A) で掘削を行います。地点JTCT-01A とJTCT-02A の両方で掘削同時検層とコア試料の採取を実施し、さらにJTCT-01A では海底下の地中温度の詳細な深度プロファイルを捉えるため、長期孔内温度計測システムを設置します。 The magnitude 9.0 earthquake that occurred off the coast of northeast Japan on 11 March 2011 was one of the largest ever recorded and caused a devastating tsunami. The earthquake happened because two tectonic plates meet and are pushing past one another in a subduction zone under the ocean offshore Japan. During the earthquake, there was a lot of slip at a shallow depth along the subduction fault where the two tectonic plates meet. This shallow slip played a major role in generating the large tsunami waves that inundated the Japanese coast. This expedition aims to investigate the conditions and processes that led to this shallow fault slip during the 2011 earthquake by collecting samples of the materials that are in and around the shallow fault and by installing sensors to monitor temperature and subseafloor fluids. These data will provide critical information about the composition, structure, mechanics, and fluids within the subduction fault and surrounding rocks that will help us understand the conditions that allow large shallow slip to occur. The findings from this expedition will address fundamental questions about how earthquakes occur in subduction zones and can provide valuable insights for assessing earthquake and tsunami risks worldwide. 詳細についてはMarE3のページをご参照ください。 科学目的、オペレーション、乗船研究者の任務等について説明するオンライン説明会が9月に開催されました。録画データはこちらからご覧いただけます。 |