今週のうなぎセミナーについてお知らせいたします。
講義室がいつもと異なりますのでご注意ください。

Here is information of the Unagi-seminar(April, 28).
Please be careful the place is different from usual.

************** Seminar on Seismology IV A, C /地震学ゼミナールIV A, C (Unagi Seminar) **************

科目：地震学ゼミナールIV A, C / Seminar on Seismology IV A, C（修士・博士）
日時：2022年 4月 28日 (木) 14:00~
場所：京都大学防災研究所 本館S棟519D　大会議室または オンライン(Zoom)

Date and Time：2022-04-28, 14:00~
Place：Seminar Room S-519D, DPRI Main Building, Uji Campus, Kyoto University or Zoom (Hybrid)

Presenter (発表者): Pousali Mukherjee

Title (題目): Along-Strike Forearc and Subducted Upper Slab Structure beneath subduction regions of Alaska and Chile and their implications towards the occurrence of Slow Slip

Abstract (要旨):Subduction zones host some of the greatest megathrust earthquakes in the world. Slow earthquakes have been also discovered around the subduction zones of the Pacific rim very close to megathrust earthquakes in several subduction zones (Obara and Kato, 2016). Investigating the lithosphere is crucial in understanding the role of the internal structure to control slow earthquakes. Deep transient slow slip had been detected in the Lower and Upper Cook Inlet (Fu et al. 2015; Li et al. 2016; Wei et al. 2012) in Alaska. In Chile, slip had been detected extending beyond 60 km depth (Socquet et al. 2017; Ruiz et al. 2014; Klein et al. 2018). We investigate the lithospheric structure beneath the region overlapping the slow earthquake and non-slow earthquake areas in Alaska and Chile along the subduction arc, using receiver function analysis and inversion method using teleseismic earthquakes. Is the typical structure the same or different that could host slow slip? For that, we investigate the velocities around the plate interface region in the lower continental mantle, subducted oceanic crust and upper oceanic mantle, as that could hold potential information that the structural heterogeneity. These regions are also surrounded by active volcanoes. We also compare and contrast our results with the other tectonic settings- volcanic region without subduction, stable regions of the Earth- such as Precambrian cratons, and try to understand the similarities and differences in the properties of the upper lithosphere from the active subduction regions. The results indicate that although the relative plate interface velocities in wedge mantle, oceanic crust and oceanic mantle along with the local structural architecture could be responsible for the slow slip in Chile, the plate interface velocities around the Alaska region with more deep slow slip is more affected only by the velocities in the subducted oceanic crust.

今後の予定（schedule）
5/5　：National holiday
5/12 ：阮、加藤
5/19 ：[JpGU rehearsal]
5/26 ：JpGU meeting
6/2　：(online JpGU) 西沢、井上
6/9　：野末、田中
6/16 ：大野、佐脇
6/23 ：山本、Chintan
6/30 ：村本、Admore
7/7　：松尾、岡田
7/14 ：小出、野田
7/21 ：森永、Frazi