Estimation of seismic ground motions and attendant potential human fatalities from scenario earthquakes on the Chishan fault in southern Taiwan

• Published in: TAO : Terrestrial, atmospheric, and oceanic sciences Vol. 28; no. 5; pp. 715 - 737
• Main Author: Liu, Kun-Sung
• Format: Journal Article
• Language: English
• Published: Taiwan 中華民國地球科學學會 01.10.2017; Chinese Geoscience Union (Taiwan); Springer
• Subjects: Age groups; Earthquakes; Emergency preparedness; Emergency response; Fatalities; Geological hazards; Ground motion; Hazard mitigation; Hazards; Households; Mitigation; Mortality; Seismic activity; Seismic hazard; Seismic response; Taiwan; Chishan Fault; Potential Human Fatality; Southern Taiwan; Shake Map; Ground Motion
• ISSN: 1017-0839; 2311-7680
• DOI: 10.3319/TAO.2017.01.06.01

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.