Recurring and triggered slow-slip events near the trench at the Nankai Trough subduction megathrust

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doi: 10.1126/science.aan3120
Author(s): Araki, Eiichiro; Saffer, Demian M.; Kopf, Achim J.; Wallace, Laura M.; Kimura, Toshinori; Machida, Yuya; Ide, Satoshi; Davis, Earl
International Ocean Discovery Program, Expedition 365 Scientists, College Station, TX
Author Affiliation(s): Primary:
Japan Agency for Marine-Earth Science and Technology, Yokusuka, Japan
Other:
Pennsylvania State University, United States
University of Bremen, Germany
GNS Science, New Zealand
University of Texas Institute for Geophysics, United States
University of Tokyo, Japan
Canadian Geological Survey, Canada
Volume Title: Science
Source: Science, 356(6343), p.1157-1160. Publisher: American Association for the Advancement of Science, Washington, DC, United States. ISSN: 0036-8075 CODEN: SCIEAS
Note: In English. 35 refs.; illus., incl. sect., geol. sketch maps
Summary: The discovery of slow earthquakes has revolutionized the field of earthquake seismology. Defining the locations of these events and the conditions that favor their occurrence provides important insights into the slip behavior of tectonic faults. We report on a family of recurring slow-slip events (SSEs) on the plate interface immediately seaward of repeated historical moment magnitude (Mw) 8 earthquake rupture areas offshore of Japan. The SSEs continue for days to several weeks, include both spontaneous and triggered slip, recur every 8 to 15 months, and are accompanied by swarms of low-frequency tremors. We can explain the SSEs with 1 to 4 centimeters of slip along the megathrust, centered 25 to 35 kilometers (km) from the trench (4 to 10 km depth). The SSEs accommodate 30 to 55% of the plate motion, indicating frequent release of accumulated strain near the trench.
Year of Publication: 2017
Research Program: IODP2 International Ocean Discovery Program
Key Words: 18 Geophysics, Solid-Earth; 19 Geophysics, Seismology; Earthquakes; Expedition 365; Geophysical methods; Geophysical profiles; Geophysical surveys; International Ocean Discovery Program; Magnitude; NanTroSEIZE; Nankai Trough; North Pacific; Northwest Pacific; Ocean floors; Pacific Ocean; Plate tectonics; Seismic methods; Seismic profiles; Slip rates; Slow slip events; Strain; Subduction; Surveys; Swarms; Thrust sheets; West Pacific
Coordinates: N330000 N340000 E1380000 E1360000
Record ID: 2017063022
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute.