Seismogenic depth of the crust beneath the Japanese Island using Japan unified hIgh-resolution relocated catalog for earthquakes (JUICE)

Tomoko E. Yano, & Makoto Matsubara

Published August 13, 2017, SCEC Contribution #7539, 2017 SCEC Annual Meeting Poster #304 (PDF)

Inspired by the SCEC CME project, we have generated a high-resolution catalog called the “Japan Unified hIgh-resolution relocated Catalog for Earthquakes” (JUICE), which can be used to evaluate the geometry and seismogenic depth of active faults in Japan. We relocated > 1.1 million hypocenters from the National Research Institute for Earth Science and Disaster Resilience (NIED) Hi-net catalog for events which occurred between January 2001 and December 2012, to a depth of 40 km. We applied a relative hypocenter determination method to the data in each grid square. Entire Japan is divided into 1257 grid squares to parallelize the relocation procedure. We used a double-difference method, incorporating cross-correlating differential times with waveform data as well as catalog differential picking times. This JUICE catalog enables us to resolve, in detail, a local seismicity distribution for the entire Japanese Islands. We estimated location uncertainty by a statistical resampling method, using Jackknife samples, and show that the relative location uncertainty can be within 0.37 km in the horizontal and 0.85 km in the vertical direction with a 90 % confidence interval for areas with good station coverage. Our seismogenic depth estimates based on D95 index, the cutoff depth where total of 95 % of events occurred, agree with the lower limit of the hypocenter distribution for recent earthquakes, such as the Chuetsu (2004, Mj 6.8), Central Tottori (2016, Mj 6.6), and Kumamoto earthquakes (2016, Mj 7.3). These agreements suggest that the new JIUCE catalog is useful for local studies and estimating the size of future earthquakes for the inland active faults.

Key Words
seismicity, earthquake catalog, hypocenter relocation, seismogenic layer

Citation
Yano, T. E., & Matsubara, M. (2017, 08). Seismogenic depth of the crust beneath the Japanese Island using Japan unified hIgh-resolution relocated catalog for earthquakes (JUICE). Poster Presentation at 2017 SCEC Annual Meeting.

Related Projects & Working Groups
Community Modeling Environment (CME)