今週のうなぎセミナーについてお知らせいたします。

Here is information of the Unagi-seminar(November, 13th).

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

科目：地震学ゼミナールIV B, D / Seminar on Seismology IV B, D（修士・博士）
日時：2025年 11月 13日 (木) 13:30~
場所：京都大学 防災研究所 本館E-232D

Date and Time：2025-11-13(Thursday), 13:30~
Place：Uji Campus Main Building E232D

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Speaker（発表者）:　伊藤 悠太 (Yuta Ito)
Title（題目）:
Comparative Analysis of Seismicity across Three Depth-Dependent Slip Regimes in the Japan Trench Subduction Zone

Abstract（要旨）:
Understanding the cause of spatial variations in seismicity is crucial for comprehending the physics governing earthquake activity. Off Iwate, in the northern Japan Trench subduction zone, the plate boundary can be divided into three distinct zones based on depth-dependent slip regimes: the slow earthquake, asperity, and stable creeping zones. We statistically compared their seismicity characteristics. Our results demonstrate that the slow earthquake zone produces significantly more aftershocks, whereas the asperity zone exhibits the lowest seismic activity. Conversely, the stable creeping zone has the highest rate of background seismicity. We interpret these distinct characteristics based on the respective broad-scale slip behaviors. Moreover, we identify a clear kink in the cumulative magnitude-frequency distribution within the stable creeping zone. Calculations of rupture arrest probability suggest a characteristic rupture size of M 3.7 (~1 km scale) in this zone. The proposed rupture arrest probability may prove useful for future studies on earthquake source physics.