Abstract. The first International Ocean Discovery Program (IODP) Core-Log-Seismic
Integration at Sea (CLSI@Sea) workshop, held in January–February 2018,
brought together an international, multidisciplinary team of 14 early-career
scientists and a group of scientific mentors specialized in subduction zone
processes at the Nankai Trough, one of the Earth's most active
plate-subduction zones located off the southwestern coast of Japan. The goal
of the workshop was to leverage existing core, log, and seismic data
previously acquired during the IODP's Nankai Trough Seismogenic Zone
Experiment (NanTroSEIZE), to address the role of the deformation front of the
Nankai accretionary prism in tsunamigenic earthquakes and slow slip in the
shallow portion of the subduction interface. The CLSI@Sea workshop was
organized onboard the D/V Chikyu concurrently with IODP Expedition
380, allowing workshop participants to interact with expedition scientists
installing a long-term borehole monitoring system (LTBMS) at a site where the
workshop's research was focused. Sedimentary cores from across the
deformation front were brought onboard Chikyu, where they were made
available for new description, sampling, and analysis. Logging data, drilling
parameters, and seismic data were also available for investigation by
workshop participants, who were granted access to Chikyu laboratory
facilities and software to perform analyses at sea. Multi-thematic presentations facilitated knowledge transfer between the
participants across field areas, and highlighted the value of
multi-disciplinary collaboration that integrates processes across different
spatiotemporal scales. The workshop resulted in the synthesis of existing
geophysical, geologic, and geochemical data spanning IODP Sites C0006,
C0007, C0011 and C0012 in the NanTroSEIZE area, the identification of key
outstanding research questions in the field of shallow subduction zone
seismogenesis, and fostered collaborative and individual research plans
integrating new data analysis techniques and multidisciplinary approaches.
Pore pressure distribution of a mega-splay fault system in the Nankai Trough subduction zone: Insight into up-dip extent of the seismogenic zone
