[S-SS04] Seismicity

Tue. May 26, 2026 3:30 PM - 5:00 PM International Conference Room (IC) (International Conference Hall, Makuhari Messe)

Chairperson:Okada Tomomi(Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University), Tagami Ayaka(Geological Survey of Japan, AIST)

The objective of this session is to discuss spatio-temporal characteristics and governing mechanisms of seismicity, focusing on earthquake activity as an ensemble rather than as individual events. In addition to case studies on regional characteristics and specific earthquake sequences, this session aims to advance our understanding of the physical and chemical processes that control seismicity. We also welcome presentations addressing interactions among seismic events at various spatio-temporal scales, the boundary conditions that define seismic activity, such as tectonics, geological structures, and thermal regimes, and phenomena associated with earthquake occurrence.

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3:30 PM - 3:45 PM

[SSS04-07] Seismic Quiescence and Activation Prior to the 1944 Tonankai Earthquake (M7.9)

*Sumio Yoshikawa

3:45 PM - 4:00 PM

[SSS04-08] Fault activity and stress field of shallow intraplate earthquakes in northern South Island, New Zealand

*Ayaka Tagami^1,8, Tomomi Okada¹, Martha K Savage², Calum J Chamberlain², Francesca Ghisetti³, Richard Sibson⁴, Kazuya Tateiwa¹, Miu Matsuno¹, Satoshi Matsumoto⁵, Yuta Kawamura⁵, Yoshihisa Iio⁶, Tadashi Sato¹, Satoshi Hirahara¹, Shuutoku Kimura¹, Stephen Bannister⁷, John Ristau⁷ (1. Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University., 2. School of Geography, Environment and Earth Sciences, Victoria University of Wellington, New Zealand., 3. TerraGeoLogica, New Zealand., 4. Department of Geology, University of Otago, New Zealand., 5. Faculty of Sciences, Kyushu University., 6. Disaster Prevention Research Institute, Kyoto University., 7. GNS Science, New Zealand., 8. Geological Survey of Japan, AIST.)

4:00 PM - 4:15 PM

[SSS04-09] Spatial and temporal variability of earthquake triggering in the 2016 M7.8 Kaikoura earthquake region: insights from ETAS modelling and b-value analysis

*Deborah Valerie Karolina Philipp-Granger^1,2, Harumi Uchida², Ryotaro Fujimura², Ayaka Tagami^3,2, Tomomi Okada² (1. Heidelberg University, 2. Tohoku University, 3. Geological Survey of Japan, AIST)

4:15 PM - 4:30 PM

[SSS04-10] Understanding the nature of fluid migration in the Noto earthquake swarm region through in-situ Vp/Vs ratio analysis

*Yihe Huang¹, Keisuke Yoshida², Aitaro Kato³, Satoshi Ide⁴ (1. University of Michigan Ann Arbor, 2. Tohoku University, 3. Earthquake Research Institute, University of Tokyo, 4. University of Tokyo)

4:30 PM - 4:45 PM

[SSS04-11] Implications for Fluid Involvement to January 6, 2026 M6.4 Earthquake in Eastern Shimane Prefecture and Deep Low-Frequency Earthquakes from a Local Seismic Velocity Structure

*Tomomi Okada¹, Masatoshi Miyazawa², Yoshihisa Iio^1,2 (1. Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University, 2. Disaster Prevention Research Institute, Kyoto University)

4:45 PM - 5:00 PM

[SSS04-12] 2025 earthquake swarm activity in the sea area near the Tokara Islands, Japan, derived from integrated land and ocean-bottom seismic observations

*Hiroshi Yakiwara¹, Tomoaki Yamada², Yusuke Yamashita³, Yukihiro Nakatani¹, Satoru Baba⁴, Eiji Kurashimo², Shinichi Sakai², Masanao Shinohara² (1. Graduate School of Science and Engineering, Kagoshima University, 2. Earthquake Research Institute, The University of Tokyo, 3. Faculty of Humanities, Miyazaki Municipal University, 4. Faculty of Science, Kyushu University)

Session information