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Lingling Ye 博士のセミナー

Seminar by Dr. Lingling Ye

セミナー等

SEMINARS

更新日:2018.10.01

Updated: 2018.10.01

ACES へ来られている Lingling Ye 博士が、10/1 に京大へ来られます。
彼女は Caltech で博士を取得し、現在は Sun Yat-sen University に所属、東大地震研へ Project researcher として訪問されております。
セミナーを以下の要領で開きたいと思いますので、奮ってご参加ください。

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Date: 1 Oct (Monday)
Time: 16:30 - 18:00
Room: C200 at the New Building of Research Center for Earthquake Prediction

Global Variations of Large Megathrust Earthquake Rupture Characteristics

Rupture characteristics of large earthquakes on subduction zone plate boundary faults vary substantially. The asperity model, proposed in the early 1980s, related regional variations of the largest earthquake size and overall rupture complexity to variations in stress heterogeneity. Repeating earthquakes, geodetic measurements of inter-seismic strain accumulation, and laboratory-based numerical modeling support the notion of frictionally locked asperities surrounded by creeping regions with different frictional properties. Yet, the fundamental nature of asperities has remained elusive for decades; the basic question is whether similar size slip patches (asperities) in different regions have similar dynamic rupture characteristics. Determining static slip distributions alone cannot resolve this issue; nor can static stress drop. Given the profoundly different rupture processes between events such as the 2004 Sumatra and 2011 Tohoku earthquakes, we need a sensitive measure of earthquake complexity that allows us to detect any regional systematics not apparent in standard measurements. We introduce a new non-dimensional source parameter, the radiated energy enhancement factor (REEF), the ratio of the directly measured broadband radiated energy to the calculated minimum radiated energy for given seismic moment and source duration. For 119 large megathrust events, we find that REEF values vary regionally, reflecting the variation of asperity properties of each subduction-zone boundary.
Segmentation, roughness, fluid distribution, and tectonic loading in the subduction zone may be responsible for such variations. For each region, fluctuations in REEF result from multiple patch interaction and triggering.
Thus, determination of REEF can better represent the rupture characteristics of great earthquakes.

直前の Leeds 大 Tim Wright 教授のセミナーの直後になります。

Date: 1 Oct (Monday)
Time: 16:30 – 18:00
Room: C200 at the New Building of Research Center for Earthquake Prediction

Speaker: Lingling Ye (Sun Yat-sen University / Earthquake Research Institute, University of Tokyo; Project researcher)

Global Variations of Large Megathrust Earthquake Rupture Characteristics

Rupture characteristics of large earthquakes on subduction zone plate boundary faults vary substantially. The asperity model, proposed in the early 1980s, related regional variations of the largest earthquake size and overall rupture complexity to variations in stress heterogeneity. Repeating earthquakes, geodetic measurements of inter-seismic strain accumulation, and laboratory-based numerical modeling support the notion of frictionally locked asperities surrounded by creeping regions with different frictional properties. Yet, the fundamental nature of asperities has remained elusive for decades; the basic question is whether similar size slip patches (asperities) in different regions have similar dynamic rupture characteristics. Determining static slip distributions alone cannot resolve this issue; nor can static stress drop. Given the profoundly different rupture processes between events such as the 2004 Sumatra and 2011 Tohoku
earthquakes, we need a sensitive measure of earthquake complexity that allows us to detect any regional systematics not apparent in standard measurements. We introduce a new non-dimensional source parameter, the radiated energy enhancement factor (REEF), the ratio of the directly measured broadband radiated energy to the calculated minimum radiated energy for given seismic moment and source duration. For 119 large megathrust events, we find that REEF values vary regionally, reflecting the variation of asperity properties of each subduction-zone boundary.
Segmentation, roughness, fluid distribution, and tectonic loading in the subduction zone may be responsible for such variations. For each region, fluctuations in REEF result from multiple patch interaction and triggering.
Thus, determination of REEF can better represent the rupture characteristics of great earthquakes.

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