2012年缅甸德贝金M 7.0地震及其地表破裂特征  

The 2012 Thabeikkjin(Myanmar)M 7.0 earthquake and its surface rupture characteristics

作　　者：常祖峰[1] 张建国[1] 申重阳[2] 李春光[1] 刘昌伟 王光明 于江[1] CHANG Zufeng;ZHANG Jianguo;SHEN Chongyang;LI Chunguang;LIU Changwei;WANG Guangming;YU Jiang(Yunnan Earthquake Administration,Kunming 650224,Yunnan,China;Institute of seismology,China Earthquake Administration,Wuhan 430071,Hubei,China)

机构地区：[1]云南省地震局,云南昆明650224 [2]中国地震局地震研究所,湖北武汉430071

出　　处：《地质力学学报》2022年第2期169-181,共13页Journal of Geomechanics

基　　金：国家自然科学基金(U2002211);国家国际科技合作专项(2015DFA21260)。

摘　　要：文章以地质地貌与地震遗迹野外调查获得的第一手资料为基础,重点介绍了实皆断裂的活动习性、2012年地震产生的建筑物破坏与地震地表破裂带特征。实皆断裂是一条规模宏大,以右旋走滑为主的全新世活动断裂,其水平滑动速率为18~20 mm/a。历史上沿实皆断裂曾发生10余次7级以上强震,迄今保留有1839年曼德勒因瓦M 8、1930年勃固M 7.3、1930年东吁M 7.3等地震遗迹。2012年德贝金M 7.0地震造成了佛塔、民用建筑等严重破坏,形成至少长45 km的地震地表破裂,包括塌岸、滑坡、地震断层等,震中烈度达Ⅸ度。在断层右旋走滑运动作用下,地裂缝呈现出有规律的左阶雁列,与实皆断裂走向的夹角一般为20°~30°;规模较大的地裂缝多呈“S”型。地裂缝有规律的左阶雁列和被断错的地物标志,指示地震地表破裂具明显的右旋走滑性质。2012年地震造成的右旋位错量一般为40~90 cm,最大位错达102 cm。地震地表破裂特征和震源机制解结果一致地表明,此次地震的发震构造为实皆活动断裂。Based on the first-hand data obtained from the field survey in terms of geology,landforms,earthquake ruins,this paper focuses on the activity behavior of the Sagaing fault,as well as the damaged buildings and seismic surface rupture zone generated by the 2012 earthquake.The Sagaing fault striking nearly NS is an active large-scale dextral strike-slip fault,with a horizontal slip rate of 18~20 mm/a.Many strong earthquakes more than M 7 have occurred along the Sagaing fault zone historically,and so far,there are still ruins of the earthquakes,such as the 1839 Innwa,Mandalay,M 8 earthquake,the 1930 Bago M 7.3 earthquake and the 1930 Phyu M 7.3 earthquake.The 2012 Thabeikkjin M 7.0 earthquake caused serious damage to pagodas,civil and other buildings,forming an at least 45 km-long seismic surface rupture with bank collapses,landslides,seismic faults and so on.The epicenter intensity of the earthquake is estimated to be IX.Under the dextral strike slip of the fault,the ground fissures show a trend of regular left-step en echelon,and the included angle with the strike of the Sagaing fault is generally 20°~30°;The large-scale ground fissures mostly show a“S”type.The regular left-step en echelon trend of ground fissures and the faulted ground features indicate that the seismic surface fracture are obviously characterized by dextral strike slip.The horizontal dextral displacements caused by the 2012 earthquake are generally between 40~90 cm,and the maximum reaches 102 cm.The surface rupture characteristics and the results of focal mechanism solutions show that the event is caused by the dextral strike-slip of the Sagaing fault.

关 键 词：德贝金 地震 实皆断裂 地震地表破裂 右旋走滑 

分 类 号：P315.2[天文地球—地震学]