CAJ | 학술논문

为了进行蒙古中部地区的深部构造观测与模型研究，中国地震局地球物理研究所和蒙古科学院天文与地球物理研究中心合作，在该地区架设了60台宽频带流动地震台．这些台站分布在被额尔齐斯-中蒙古-额尔古纳断裂隔断的加里东、海西两个构造域．本文选取了2011年8月-2012年7月部分台站记录的震中距在85°-135°且 MW ≥5．0的远震事件，通过SplitLab 软件来进行 SKS 分析．使用最小能量法、旋转相关法和最小特征值法进行处理，取得了蒙古中部地区各向异性的初步结果．结果显示：快慢波延时在0．8-2．0 s 之间．西北部区域靠近杭爱山脉与肯特山脉的区域构造走向均为 ENE--WSW 方向，而快波方向大多为N40°W，与区域构造走向近似垂直．根据 HS3-NUVEL-1A 板块模型计算的该地区板块绝对运动方向与快波偏振方向呈顺时针约15°夹角．然而，有个别台站表现出了两种模式的快波分裂，其中一种与当地 ENE--WSW 向的断裂方向近似一致．
위료진행몽고중부지구적심부구조관측여모형연구，중국지진국지구물리연구소화몽고과학원천문여지구물리연구중심합작，재해지구가설료60태관빈대류동지진태．저사태참분포재피액이제사-중몽고-액이고납단렬격단적가리동、해서량개구조역．본문선취료2011년8월-2012년7월부분태참기록적진중거재85°-135°차 MW ≥5．0적원진사건，통과SplitLab 연건래진행 SKS 분석．사용최소능량법、선전상관법화최소특정치법진행처리，취득료몽고중부지구각향이성적초보결과．결과현시：쾌만파연시재0．8-2．0 s 지간．서북부구역고근항애산맥여긍특산맥적구역구조주향균위 ENE--WSW 방향，이쾌파방향대다위N40°W，여구역구조주향근사수직．근거 HS3-NUVEL-1A 판괴모형계산적해지구판괴절대운동방향여쾌파편진방향정순시침약15°협각．연이，유개별태참표현출료량충모식적쾌파분렬，기중일충여당지 ENE--WSW 향적단렬방향근사일치．
A passive seismic array with 60 broadband seismometers was deployed in the central Mongolia by the cooperation between Institute of Geophysics, China Earthquake Administration and Research Center of Astronomy and Geo-physics,Mongolian Academy of Sciences,to carry out the deep structure obser-vation and modeling study.The passive seismic array was distributed within the Caledonian orogen and the Hercynian orogen separated by the Ergis-central Mongolia-Eerguna fault zone.The teleseismic waveform data from part of the array with the epicentral distance of 85°-135°and MW 5.0,from August 2011 to July 2012,was selected to do SKS splitting analysis through the SplitLab package.Three methods,i.e.,the minimum energy of tangential component (SC),the rotation and correlation (RC),and eigenvalue (EV),are simultane-ously applied for each SKS waveform data.The preliminary anisotropy result was obtained for the central Mongolia.It shows that the time delay between fast and slow waves is within 0.8-2.0 s,and the polarization direction of fast wave is about N40°W,almost perpendicular to the geological structure strike direction of ENE--WSW.The fast direction is about 15°systematically clock-wise to the absolute plate motion inferred from the HS3-NUVEL-1A model.It is also noted that not only the two different splitting modes are simultaneously observed beneath certain station,but also the fast wave direction parallel to the ENE--WSW striking direction exists beneath certain station.