| Session Details | |
| Section | SE - Solid Earth Sciences |
| Session Title | New Perspectives on Subduction Zone Megathrust Earthquakes |
| Main Convener | Prof. Kyuichi Kanagawa (Chiba University, Japan) |
| Co-convener(s) | Prof. Harold Tobin (University of Wisconsin - Madison, United States) Prof. César Ranero (Instituto de Ciencias del Mar, Spain) Dr. Ryota Hino (Tohoku University, Japan) Dr. Satoshi Ide (The University of Tokyo, Japan) |
| Session Description | The Mw 9.0 Tohoku-oki earthquake and its accompanying tsunami on March 11, 2011 devastated a large area along the Pacific coast of NE Japan, killing at least 15,880 people and leaving about 2,650 people still missing. Such megathrust earthquakes at subduction zones and their accompanying tsunamis have caused severe damage in the past. Scientists have worked for decades to understand subduction zone earthquakes and related phenomena, mostly based on seismic and geodetic observations. In addition to these remote monitoring studies, the challenge of drilling into and directly sampling megathrust earthquake faults at depth, analysis of and experiments on sampled fault materials, and borehole measurements at depth have recently been taken up by the Integrated Ocean Drilling Program (IODP) projects at Nankai Trough (Nankai Trough Seismogenic Zone Experiment; NanTroSEIZE), Japan Trench (Japan Trench Fast Drilling Project; JFAST), and off Costa Rica (Costa Rica Seismogenesis Project; CRISP). The JFAST expedition in 2012 successfully sampled the plate boundary megathrust near the trench, which is shown to have slipped during the 2011 Tohoku-oki earthquake by seismological, tsunami and geodetic studies. The NanTroSEIZE expeditions started in 2007, and target sampling the seismogenic megasplay fault at a depth of ~5200 m below seafloor in 2015. The CRISP project targets sampling the seismogenic plate boundary megathrust in the next decade. These IODP projects are providing us a new perspective on megathrust earthquakes. In this session, we welcome presentations based on such frontier studies, in addition to those based on seismic and geodetic observations and numerical modeling. This session is sponsored by Japanese MEXT grant “KANAME” (KAkenhi for NAnkai Megathrust Earthquakes), and we also anticipate many presentations on the outcomes of the KANAME studies. |