International Joint Workshop on
Slow-to-Fast Earthquakes 2025

Plenary Sessions

• Environment and generation processes of slow and fast phenomena

Scope:

The occurrence of slow to fast seismic phenomena in faults has been widely discovered in various geological environments around the world. Geophysical and geological observations in subduction zones have shown that the occurrence and distribution of slow and fast earthquakes are non-uniform, suggesting that the temperature and pressure of the generation zone, the presence of fluids, and the rheology of the materials within the zone play an important role. The objective of this session is to facilitate discussion on the environment of the generation zone and the generation process of slow and fast phenomena, grounded in data obtained from seismic and geodetic observations, geological field surveys, laboratory experiments and numerical modelling. We encourage interdisciplinary research on slow-to-fast phenomena that occur in various settings, including beyond plate boundaries, but also on land faults, geological storage fields, landslides and glacial environments. We also invite contributions on geological analogue research that constrains the condition of the generation, and experimental research that focuses on the physico-chemical processes that transition from slow-to-fast/fast- to-slow slip.

Keynote speakers: Samuel Papeschi (CNR-IGG), Junichi Nakajima (Institute of Science Tokyo)

Moderators:  Yohei Hamada, Asuka Yamaguchi

• Cutting-Edge Approaches to Measurement and Data Analysis

Scope:

The development of novel observational techniques and the utilization of earthquake big data promote a comprehensive understanding of the diversity of slow earthquakes and the transition from slow to fast earthquakes or vice versa. Recent advances in multi-scale measurements, including distributed acoustic sensing (DAS), precise geodetic observations on land, and new seafloor monitoring techniques, allow us to capture the previously undetectable spatiotemporal evolution of slow and fast earthquakes. Additionally, data-driven approaches leveraging machine learning, statistical methods, and rapid analysis techniques uncover hidden statistical and geophysical characteristics of slow-to-fast earthquakes. In this session, we welcome contributions to the development of observational techniques, data analysis methods, and their seismological and geodetic applications to real natural phenomena.

Keynote speakers: Yijian Zhou (California Institute of Technology), Eiichiro Araki (Japan Agency of Marine-Earth Science and Technology)

Moderators:  Yoshiyuki Tanaka, Aitaro Kato, Yuji Itoh

• Data-constrained numerical modeling and model-informed

Scope:

We invite research that integrates modeling and observations to develop a comprehensive understanding of slow and fast earthquakes and related phenomena. By grounding models on real data, we aim to generate predictive results that directly correspond to geophysical and geological observations. At the same time, new observational studies and reanalyses of existing data are crucial for testing model predictions, validating accuracy, and driving further model refinements. Applying these approaches across diverse regions and tectonic settings is also essential for advancing our understanding of these processes globally. This session welcomes contributions that promote hypothesis-driven research through real-world applications.

Keynote speakers: Tianhaozhe Sun (Geological Survey of Canada), Yoshihiro Kaneko (Kyoto University) 

Moderators:  Yoshihiro Ito, Takanori Matsuzawa