Accretionary prism deformation and fluid migration caused by slow earthquakes in the Nankai subduction zone

Tonegawa, Takashi; Akuhara, Takeshi; Yamashita, Yusuke; Sugioka, Hiroko; Shinohara, Masanao; Takemura, Shunsuke; Tsuji, Takeshi

doi:https://doi.org/10.5194/se-16-579-2025

Articles | Volume 16, issue 6

https://doi.org/10.5194/se-16-579-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/se-16-579-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 16, issue 6

Research article

|

30 Jun 2025

Research article |

| 30 Jun 2025

Accretionary prism deformation and fluid migration caused by slow earthquakes in the Nankai subduction zone

Takashi Tonegawa, Takeshi Akuhara, Yusuke Yamashita, Hiroko Sugioka, Masanao Shinohara, Shunsuke Takemura, and Takeshi Tsuji

Supplement

https://doi.org/10.5194/se-16-579-2025-supplement

Data sets

Dataset of dv/v and CC using DONET and temporary OBSs in the Nankai subduction zone T. Tonegawa https://doi.org/10.5281/zenodo.15048965

National Research Institute for Earth Science and Disaster Resilience NIED https://doi.org/10.17598/NIED.0008

Short summary

This study demonstrates that for slow earthquakes in the shallow Nankai subduction zone, (1) the seismic velocity reductions in the accretionary prism reflect the stress field changes due to the slow earthquakes, and (2) the temporal variations in the heterogeneous structure correspond to upward fluid migrations from the source region of the slow earthquakes.