日本地球惑星科学連合2023年大会

講演情報

[J] 口頭発表

セッション記号 S (固体地球科学) » S-TT 計測技術・研究手法

[S-TT44] 最先端ベイズ統計学が拓く地震ビッグデータ解析

2023年5月21日(日) 10:45 〜 12:00 301B (幕張メッセ国際会議場)

コンビーナ:長尾 大道(東京大学地震研究所)、加藤 愛太郎(東京大学地震研究所)、矢野 恵佑(統計数理研究所)、椎名 高裕(産業技術総合研究所)、座長:長尾 大道(東京大学地震研究所)、矢野 恵佑(統計数理研究所)、加藤 愛太郎(東京大学地震研究所)、椎名 高裕(産業技術総合研究所)

11:45 〜 12:00

[STT44-05] Instantaneous tracking of earthquake growth with elastogravity signals

★Invited Papers

*Bertrand Rouet-Leduc1、Andrea Licciardi2、Quentin Bletery2、Kevin Juhel2、Jean-Paul Ampuero2 (1.DPRI, Kyoto University, Japan、2.Géoazur, IRD, France)

キーワード:Earthquake early warning, Prompt elasto-gravity signals, Deep learning

Rapid and reliable estimation of large earthquake magnitude (above 8) is key to mitigating the risks associated with strong shaking and tsunamis. Standard early warning systems based on seismic waves fail to rapidly estimate the size of such large earthquakes. Geodesy-based approaches provide better estimations, but are also subject to large uncertainties and latency associated with the slowness of seismic waves. Recently discovered speed-of-light prompt elastogravity signals (PEGS) have raised hopes that these limitations may be overcome, but have not been tested for operational early warning. Here we show that PEGS can be used in real time to track earthquake growth instantaneously after the event reaches a certain magnitude. We develop a deep learning model that leverages the information carried by PEGS recorded by regional broadband seismometers in Japan before the arrival of seismic waves. After training on a database of synthetic waveforms augmented with empirical noise, we show that the algorithm can instantaneously track an earthquake source time function on real data. Our model unlocks ‘true real-time’ access to the rupture evolution of large earthquakes using a portion of seismograms that is routinely treated as noise, and can be immediately transformative for tsunami early warning.