Taiwan Earthquake Model: PSHA and Scenario Hazard Map

Kuo-Fong Ma, & Taiwan Earthquake Model (TEM) team

Published August 2, 2017, SCEC Contribution #7391, 2017 SCEC Annual Meeting Poster #260

Taiwan Earthquake Model (TEM) using GEM OpenQuake engine for the assessment of seismic hazards of Taiwan. The first version of TEM probabilistic seismic hazard analysis for Taiwan was published in 2015 (TEM PSHA2015, Wang et al., 2016a). The model adopts the source parameters of 38 seismogenic structures (Shyu et al., 2016), which are to specific fault source-based categorization, and seismic activities as categorized as areal, and subduction zone (intraplate, and interpolate) sources. To evaluate the potential ground-shaking resulting from each seismic source, the corresponding ground-motion prediction equations for crustal and subduction earthquakes were adopted. The studies show high hazard probability in Southwestern Taiwan and the Longitudinal Valley of Eastern Taiwan due to the densely distributed seismogenic structure sources. The seismic source parameters adopted in the 2015 PSHA of the TEM (TEM PSHA2015) was examine for the reliability test of the seismic source models (Wang et al., 2016b) using M > 4.0 mainshocks in the 23-year data period of 1993–2015for the areal and subduction zone sources with the time-independent Poisson assumption. The high contribution of the PGA from areal sources is an important notion in Tawian as many seismicity was from buried structure rather than the identified surface ruptured faults. We adopted the disaggregation analysis from a hazard map to determine the contribution of the individual seismic sources to hazard for six metropolitan cities in Taiwan. For densely populated faults in SW Taiwan, maximum magnitude is more sensitive than the slip rate, giving the concern on the possible multiple fault segments rupture with larger magnitude in this area, which was not yet considered in TEM PSHA2015. The source category disaggregation also suggested that special attention is necessary for intraplate earthquakes for short period motion, and interplate for long-period shaking seismic hazards in Northern Taiwan. A further effort will be on Scenario Based Hazard from selected seismogenic sources and potential multiple fault segments ruptures for deterministic hazard assessment for metropolitan cities.

Key Words
TEM, PSHA, Scenario

Ma, K., & (TEM) team, T. (2017, 08). Taiwan Earthquake Model: PSHA and Scenario Hazard Map. Poster Presentation at 2017 SCEC Annual Meeting.

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