The 2014 Northern Thailand Mw 6.1 Earthquake and its Seismogenic Tectonics  

作　　者：CHANG Zufeng DONG Pin-liang YUAN Renmao HOU Jianjun HE Zhongtai LI Jianlin CHANG Hao 

机构地区：[1]Yunnan Earthquake Agency,Kunming 650224,China [2]Department of Geography and the Environment,University of North Texas,Denton,TX 76203,USA [3]Key Laboratory of Active Tectonics and Volcanism,Institute of Geology,China Earthquake Administration,Beijing 100029,China [4]School of Earth of Space Sciences,Peking University,Beijing 100871,China [5]National Institute of Natural Hazards,MEMC,Beijing 100085,China

出　　处：《Acta Geologica Sinica(English Edition)》2022年第2期648-660,共13页地质学报（英文版）

基　　金：financially supported by National Institute of Natural Hazards,Ministry of Emergency Management of China(Grant No.ZDJ2019-21);the National Science Foundation of China(Grant No.41472204)。

摘　　要：On May 5, 2014, an earthquake with a magnitude of Mw 6.1(the largest earthquake in Thailand so far) occurred in Chiang Rai of the Golden Triangle area in northern Thailand. We had an opportunity to conduct field survey immediately after the earthquake. Serious damage to buildings and casualties of lives were observed, and the estimated Maximum Mercalli Intensity(MMI) of the earthquake is Ⅷ(evaluated according to the MMI scale of the Chinese Standard). No long continuous ground ruptures were produced during the earthquake, but in the epicenter(commonly within MMI Ⅷ extent), massive small linear ruptures(usually several tens of meters long) developed and displayed intriguing structural features, offsetting many roads several centimeters left laterally on NE trending cracks or offsetting right laterally on NW trending ones. The focal mechanism solution of earthquake shows that this is a pure strike-slip event, and two nodal planes in NW and NE directions had the same motion senses respectively as those of breakage associated with the earthquake. The long axis of the isoseismals and aftershock distributions are in NE direction,which is consistent with the strike of Luang Namtha fault. The 230-km-long Luang Namtha fault which starts from the border of China and Laos, runs through northern Laos, and terminates at Chiang Rai of Thailand is predominated by left-lateral strike-slip and active in late Quaternary, and two earthquakes over Ms 6.0 occurred along the fault in 1925 and 2007 respectively. This Mw 6.1 earthquake occurred at the southwestern end of the fault. All related features such as evident structural rupturing, elongated orientation of MMI and aftershock distribution,as well as the location of the epicenter,suggest that the Luang Namtha fault may be responsible for the 2014 Northern Thailand earthquake.

关 键 词：Mw 6.1 earthquake seismogenic tectonics Luang Namtha fault Indochina Block northern Thailand 

分 类 号：P315.2[天文地球—地震学]