日本地球惑星科学連合2015年大会

講演情報

インターナショナルセッション(口頭発表)

セッション記号 S (固体地球科学) » S-SS 地震学

[S-SS02] Frontier studies on subduction zone megathrust earthquakes and tsunamis

2015年5月25日(月) 16:15 〜 18:00 国際会議室 (2F)

コンビーナ:*金川 久一(千葉大学大学院理学研究科)、Demian Saffer(Dept. of Geosciences, The Pennsylvania State University, USA)、Michael Strasser(Geological Institute, Seiss Federal Insitute of Technology ETH Zurich)、山田 泰広(京都大学工学研究科都市社会工学専攻)、小平 秀一(海洋研究開発機構 地球内部ダイナミクス領域)、日野 亮太(東北大学災害科学国際研究所)、氏家 恒太郎(筑波大学生命環境系)、伊藤 喜宏(京都大学防災研究所)、座長:氏家 恒太郎(筑波大学生命環境系)、金川 久一(千葉大学大学院理学研究科)

16:15 〜 16:35

[SSS02-20] Unlocking the secrets of slow slip at the Hikurangi subduction margin

*Laura WALLACE1Demian SAFFER2Yoshihiro ITO3Stuart HENRYS4Philip BARNES5Kimihiro MOCHIZUKI6Joshu MOUNTJOY5Stephen BANNISTER4Michael UNDERWOOD7Shuichi KODAIRA8Rob HARRIS9 (1.University of Texas, Institute for Geophysics、2.Pennsylvania State University、3.Kyoto University、4.GNS Science, New Zealand、5.NIWA, New Zealand、6.University of Tokyo, ERI、7.University of Missouri、8.JAMSTEC、9.Oregon State University)

キーワード:subduction, slow slip events, GPS, scientific drilling, seafloor geodesy, New Zealand

The northern Hikurangi subduction margin, New Zealand is the site of the shallowest well-documented slow slip events (SSEs) on Earth. Due to the close proximity of the SSE source area to the seafloor at the offshore Hikurangi margin (<5-15 km), it has become an important international target for a variety of geophysical studies to understand the offshore physical mechanisms that lead to slow slip. The centerpiece of these efforts is a series of IODP proposals to undertake riserless (Joides Resolution) and riser (Chikyu) drilling, and CORK observatory installation on a transect spanning the shallow Hikurangi SSEs. We understand that if scheduling of riserless drilling (and observatory installation) occurs, it is likely for 2017. We will discuss the plans and scientific objectives for both riser and riserless drilling, and borehole observatories. We will discuss other ongoing experiments at the northern Hikurangi margin, including an upcoming heatflow survey, and recent seafloor geodetic (Absolute Pressure Gauges) and OBS deployments to undertake near-source investigations of SSE deformation and related seismicity of the shallow (<10 km depth) subduction thrust (the HOBITSS project). We will also present preliminary analysis of slip distribution and seismicity (using onshore data) from a large SSE that occurred in October 2014 directly beneath the HOBITSS network.