International Joint Workshop on
Slow-to-Fast Earthquakes 2023

Plenary Sessions

• Slow-to-Fast Earthquakes around Metropolitan Areas

Scope:

In the 100 years since the Great Taisho Kanto earthquake, the world has experienced many earthquakes, including megathrust and inland earthquakes. Such earthquakes are expected to occur in the future, and events that occur in or near large cities will cause enormous disasters. How to deal with them is a scientific as well as a social issue. Recent developments in seismic and geodetic observations, analytical techniques, and theoretical research have made it possible to better understand earthquake phenomena and mechanisms. Based on such understanding, there have been discussions on the evaluation of seismogenic potential. These include, for example, studies on the behavior of slow earthquakes and the interaction between slow and fast earthquakes, statistical analysis using earthquake catalogs, understanding induced seismic activity, and data assimilation.

This session focuses on understanding seismic and geodetic phenomena on relatively short time scales (<~100 years) and welcomes submissions on advanced methods for evaluating seismogenic potential (e.g., observation and analysis techniques, modeling, etc.).

Keynote speakers:
Ross Stein (Temblor, Inc.)
Anne Socquet (Université Grenoble Alpes, CNRS, IRD, ISTerre)

Moderators: 

Yoshiyuki Tanaka, Aitaro Kato, Hitoshi Hirose, Takane Hori 

• Connecting Geophysical and Geological Timescales of Slow and Fast Earthquakes

Scope:

The earthquake phenomena encompass a broad spectrum of timescale processes. Beyond the seismologically observed variations in earthquake timescales, which span from slow to fast events, there are processes operating on timescales ranging from milliseconds to thousands of years. These processes, including microcrack formation, slip propagation, fault and host rock diagenesis, and strain accumulation, among others, contribute to the occurrence of earthquakes. Gaining a comprehensive understanding of earthquakes necessitates delving into the mechanisms that span this wide range of timescales. In this regard, geophysics and geology serve as crucial and complementary disciplines. This session aims to explore physical and chemical processes across various timescales, utilizing data from seismic and geodetic observations, geological field studies, laboratory experiments, and numerical modeling. Specifically, the session will present topics related to long-term processes, such as fault strength recovery and major earthquake recurrence, from the perspective of geology, experiment, and modeling.

Keynote speakers:
Michael Strasser (University of Innsbruck)
Atsushi Okamoto (Tohoku University)

Moderators: 

Yohei Hamada, Asuka Yamaguchi, Takahiro Hatano, Takanori Matsuzawa, Makoto Otsubo 

• Comparative Convergentlogy on Slow-to-Fast Earthquake Science  

Scope:

Both slow and fast ruptures on faults are observed worldwide in a variety of tectonic settings, from shallow to deep sections on convergence margins, such as collision and subduction margins. This session aims to identify common and individual factors controlling such slow and fast ruptures at both convergence margins using data from seismic and geodetic observations, geologic fieldwork, laboratory experiments, and numerical modeling. In addition to studies that focus on slow-to-fast geophysical and geologic processes, we also welcome contributions that highlight slow and fast deformation processes in landslide, glacial, and mud-volcanic environments and others, as these can provide important analogs for better understanding.

Keynote speakers:
Kate Huihsuan Chen (National Taiwan Normal University)
Saeko Kita (Building Research Institute)

Moderators: 

Yoshihiro Ito, Kimihiro Mochizuki, Kohtaro Ujiie, Saeko Kita