[S-CG56] Science of Slow and Fast Earthquakes

Tue. May 26, 2026 10:45 AM - 12:15 PM Convention Hall (CH-B) (International Conference Hall, Makuhari Messe)

Chairperson:Itoh Yuji(Earthquake Research Institute, the University of Tokyo), Okada Yutaro(International Research Institute of Disaster Science)

Growing evidence of geophysical observations has demonstrated that earthquake faults host a broad spectrum of slip modes from slow to unstable fast slip, which may lead to complexity in the nucleation process, rupture behavior, and slip and energy distribution. This discovery has boosted up vigorous discussions about the connection between slow and fast earthquakes including large earthquakes. How and when does a slow earthquake become a fast earthquake? What geological and geophysical structural differences distinguish slow earthquakes from fast ones? To answer these fundamental questions, it is particularly important to proceed further global and interdisciplinary research through the integration of geophysics, seismology, geodesy, geology, and physics. Advancements in measurement technology, the application of information science and statistical methods to seismic big data, and the utilization of high-performance computing are required as key ingredients in accelerating the integration. In addition, various subduction zone phenomena, including earthquakes, volcanic eruptions, and surface processes , often occur as a cascading series of events, necessitating a system-wide, integrative approach. This session encourages presentations shedding light on geophysical observations, data analysis, field studies, laboratory experiments, numerical modeling, and theoretical studies, as well as comparative investigations across onshore fault zones and multiple subduction systems. We also welcome contributions from cutting-edge science and technology fields that explore development of novel measurements, data-driven analysis, and large-scale computation that are relevant to our understanding of slow and fast earthquakes and other subduction zone phenomena. This session is organized by the JpGU Science of Slow and Fast Earthquake Focus Group and the SZ4D initiative.

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10:45 AM - 11:00 AM

[SCG56-13] Early results from a Dense, Deep-water GNSS-Acoustic Network in the Aleutian 1946 Tsunami Earthquake Rupture Area

★Invited Papers

*Andrew Vern Newman¹, Surui Xie², Mark Zumberge³, Nathalie Chavarria³, Glenn Sasagawa³, Dennis Rimington³, Dave Price³ (1. Georgia Institute of Technology, 2. University of Houston, 3. University of California San Diego)

11:00 AM - 11:15 AM

[SCG56-14] Tracking short-term slow slip along Nankai with GNSS: temporal evolution of slip rate and interaction with the seismogenic zone

*Louise Maubant¹, Yuji Itoh¹, Aitaro Kato¹ (1. Earthquake Research Institute, The university of Tokyo)

11:15 AM - 11:30 AM

[SCG56-15] Detection of short-term SSEs around Okinawa Island using an ultra-dense GNSS data

Naoyuki ABIRU², *Takuya NISHIMURA¹, SHINICHI MIYAZAKI², Takeshi Matsushima³ (1. Disaster Prevention Research Institute, Kyoto University, 2. Graduate School of Science, Kyoto University, 3. Faculty of Science, Kyushu University)

11:30 AM - 11:45 AM

[SCG56-16] Spatiotemporal distribution and along-strike variations of long-term slow slip events in the entire Nankai Trough inferred from GNSS data

Teruki Takahashi¹, *Ryota Takagi¹, Yutaro Okada², Ryota Hino¹ (1. Graduate School of Science, Tohoku University, 2. International Research Institute of Disaster Science, Tohoku University)

11:45 AM - 12:00 PM

[SCG56-17] Detection of Possible Slow Slip Events Using Seismic & Geodetic Approaches in Costa Rica

*Takashi Nishizawa¹, Tomoaki Nishikawa², Yuta Mitsui³, Yukitoshi Fukahata² (1. Graduate School of Science, Kyoto University, 2. Disaster Prevention Research Institute, Kyoto University, 3. Department of Geosciences, Shizuoka University)

12:00 PM - 12:15 PM

[SCG56-18] Interactions Between Slow and Fast Megathrust Slip Revealed by the 2024–2025 Hyuga-nada Earthquake Sequence

*XIAOLONG ZHANG^1,2, Yuji Itoh³, Shaoyang Li¹, Takuya NISHIMURA⁴ (1. State Key Laboratory of Lithospheric and Environmental Coevolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, 2. College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China, 3. Earthquake Research Institute, The University of Tokyo, Tokyo, Japan, 4. Disaster Prevention Research Institute, Kyoto University, Uji, Japan)

Session information