日本地球惑星科学連合2023年大会

講演情報

[J] オンラインポスター発表

セッション記号 S (固体地球科学) » S-CG 固体地球科学複合領域・一般

[S-CG61] 広域観測・掘削・微視的実験協働沈み込み帯地震の場とメカニズム

2023年5月25日(木) 10:45 〜 12:15 オンラインポスターZoom会場 (20) (オンラインポスター)

コンビーナ:木下 正高(東京大学地震研究所)、荒木 英一郎(海洋研究開発機構)、Hiroko Kitajima(Texas A&M University College Station)、廣瀬 丈洋(国立研究開発法人海洋研究開発機構 高知コア研究所)

現地ポスター発表開催日時 (2023/5/24 17:15-18:45)

10:45 〜 12:15

[SCG61-P06] 地震断層の動的すべり挙動の解明に向けた放射光オペランド摩擦実験構想

*廣瀬 丈洋1武藤 潤2、八木 和行3 (1.国立研究開発法人海洋研究開発機構 高知コア研究所、2.東北大学大学院理学研究科、3.九州大学大学院工学研究院)

A fault experiences rapid movement at velocities exceeding meters per second during large earthquakes, inevitably generating heat as a result of friction on the fault surfaces. This heat triggers a variety of thermally activated physico-chemical processes such as gelification, melting and degassing, the products of which serve to lubricate the fault during the seismic event (Di Toro et al., 2011). However, these coseismic products form at fast-moving micro-contacts (i.e. asperities) and are instantaneously present at the onset of coseismic faulting, primarily as a result of non-equilibrium chemical reactions. The dynamic processes at these micro-contacts are therefore notoriously difficult to confirm without in-operando observation.

To confirm the existence of these metastable products formed at the micro-contacts, and to understand their mechanical effects on coseismic faulting, it is essential to establish a high-speed friction apparatus capable of reproducing coseismic faulting on a synchrotron beamline. Our aim is to redesign a pin-on-disk tribological apparatus, which has already been successfully developed for use at the beamline (Yagi et al., 2016 Tribol. Lett.), to accommodate experiments on geomaterials. The redesigned apparatus, in conjunction with synchrotron microtomography and X-ray diffraction studies, will allow us to gain greater insight into the dynamic physico-chemical processes involved during earthquakes. In our presentation, we will review previous studies on dynamic processes during coseismic faulting and outline our plans for the future apparatus of in-operando friction experiments with synchrotron radiation.