Estimation of Seismic Ground Motions and Attendant Potential Human Fatalities from Scenario Earthquakes on the Chishan Fault in Southern Taiwan

Abstract

The purpose of this study is to estimate maximum ground motions in southern Taiwan as well as to assess potential human fatalities from scenario earthquakes on the Chishan active faults in this area. The resultant Shake Map patterns of maximum ground motion in a case of M w 7.2 show the areas of PGA above 400 gals are located in the northeastern, central and northern parts of southwestern Kaohsiung as well as the southern part of central Tainan, as shown in the regions inside the yellow lines in the corresponding figure. Comparing cities with similar distances located in Tainan, Kaohsiung, and Pingtung to the Chishan fault, the cities in Tainan area have relatively greater PGA and PGV, due to large site response factors in Tainan area. Furthermore, seismic hazards in terms of PGA and PGV in the vicinity of the Chishan fault are not completely dominated by the Chishan fault. The main reason is that some areas located in the vicinity of the Chishan fault are marked with low site response amplification values from 0.55 -1.1 and 0.67 -1.22 for PGA and PGV, respectively. Finally, from estimation of potential human fatalities from scenario earthquakes on the Chishan active fault, it is noted that potential fatalities increase rapidly in people above age 45. Total fatalities reach a high peak in age groups of 55 -64. Another to pay special attention is Kaohsiung City has more than 540 thousand households whose residences over 50 years old. In light of the results of this study, I urge both the municipal and central governments to take effective seismic hazard mitigation measures in the highly urbanized areas with a large number of old buildings in southern Taiwan. Article history:Received 19 August 2016 Revised 6 January 2017 Accepted 6 January 2017 Keywords:Chishan Fault, Potential Human Fatality, Ground Motion, Shake Map, Southern Taiwan Citation:Liu, K.-S., 2017: Estimation of seismic ground motions and attendant potential human fatalities from scenario earthquakes on the Chishan fault in southern Taiwan. Terr.

Estimation of Seismic Ground Motions and Attendant Potential Human Fatalities from a Scenario Earthquake on the Hsincheng Active Fault in Taohsin Area, Taiwan

“…Der Kiureghian and Ang's fault rupturing patterns have been widely cited by the engineering community until now. In this study, with the actual seismic recording data, do not do the seismic source partition, to use more than 2000 earthquakes calculated seismic intensity probability to estimate the potential of seismic hazards in Taoyuan and Hsinchu area, and the site effect factor included in the estimation model of strong seismic ground motions, we can get closer to the actual situation of the ground motion estimates, in order to more accurately estimate the potential of earthquake hazards [12][13][14][15][16][17][18]. In addition to the shallow earthquakes of magnitude greater than 5 mentioned above, this study also includes Sanchiao fault, Hsincheng fault, Hukou fault and Hsinchu fault to calculate with the fault rupture patterns in order to avoid the seismic hazard of underestimating near fault areas by only using point sources.…”

Estimation of Seismic Ground Motions and Attendant Potential Human Fatalities from Scenario Earthquakes on the Sanchiao Fault in Taipei City, Taiwan

“…Accordingly, a realistic estimation of total human fatalities in areas of high seismic intensity, either before a large earthquake by performing scenario studies, or shortly after a real earthquake by a system of rapid intensity mapping can be made. The age dependence of human fatality rate used in this study to calculate the number of fatalities is expressed as follows [7,9,10]:…”

“…In addition, some Scenario Earthquakes on the Sanchiao Fault in Taipei City, Taiwan studies estimated potential seismic hazards in southern Taiwan in the form of ShakeMaps. Particularly, the site response factor is incorporated into their ground motion prediction models to obtain more realistic peak ground motion estimates for assessment of potential seismic hazards [3][4][5][6][7].…”

Introduction to the special issue on the 2016 Meinong, Taiwan, earthquake

“…However they emphasized that the Meinong event did release about 16% of total seismic hazard potential for the 475 years return period; the seismic hazard potential remains high in southern Taiwan. Liu (2017) calculated the maximum PGA ShakeMap for M w 6.8 -7.2 scenario earthquakes occurred on the Chishan fault in southern Taiwan and discussed the resulted hazard and possible human fatalities in the major cities Kaohsiung and Tainan. Based on the simulation results, he urged the government to take effective actions on seismic hazard mitigation measures in the highly urbanized Kaohsiung and Tainan cities.…”