[J04-3] Geohazard early warning systems III

[J04-3-01] Testing of GMPEs for absolute velocity response spectra for earthquake early warning of long-period ground motion intensity in Japan

^○Yadab P. Dhakal, Wataru Suzuki, Takashi Kunugi, Shin Aoi (National Research Institute for Earth Science and Disaster Resilience)

We constructed ground motion prediction equations (GMPEs) for absolute velocity response spectra (AVRS) at periods between 1 s and 10 s with an objective of rapid prediction of long-period ground motion intensities recently proposed by Japan Meteorological Agency (JMA) for earthquake early warning (EEW) (Dhakal et al. 2015). The GMPEs require JMA magnitude and hypocentral distance as basic input parameters and the values are corrected for site conditions a priory defined. The JMA magnitude, that is an amplitude-based magnitude, is estimated faster than moment magnitude. The success of predictions for future events depends on whether the future events are sufficiently similar to the trained events in the GMPE models in terms of location, magnitude, and individuality of the events. The GMPEs used data from events having Mw >= 6.5 and recorded by K-NET and KiK-net until 2012. In this paper, we discuss performance of the GMPEs for recent large earthquakes that occurred in Japan after the construction of the GMPEs. We found that the GMPEs performed satisfactorily in the region of high intensities but performed relatively poorly at distances beyond about 200 km in the case of the 2016, Mw 7.1 Kumamoto earthquake. We found that the event errors associated with the Kumamoto earthquake are quite larger than those for the events employed in the GMPEs. It is found that a part of the errors is from a bias due to an uneven azimuthal coverage of the data at long distances. For other large events that occurred in off the Pacific Coast of Japan (e.g., 2016 Nov 22, 05:59 JST, Mw 7.0, east off Fukushima Prefecture earthquake; 2015 Feb 17, 08:06 JST, Mw 6.7, far east off Sanriku earthquake), we found that the results are satisfactory.
References
Dhakal YP, Suzuki W, Kunugi T, Aoi S, 2015, Ground motion prediction equations for absolute velocity response spectra (1-10 s) in Japan for earthquake early warning, Journal of Japan Association for Earthquake Engineering 15(6), 91:111.