大地测量与地球动力学
大地測量與地毬動力學
대지측량여지구동역학
JOURNAL OF GEODESY AND GEODYNAMICS
2009年
6期
1-7
,共7页
乔学军%游新兆%杨少敏%王琪%杜瑞林
喬學軍%遊新兆%楊少敏%王琪%杜瑞林
교학군%유신조%양소민%왕기%두서림
InSAR%同震形变%当雄%亚东-谷露裂谷%念青唐古拉山南东麓断裂带
InSAR%同震形變%噹雄%亞東-穀露裂穀%唸青唐古拉山南東麓斷裂帶
InSAR%동진형변%당웅%아동-곡로렬곡%념청당고랍산남동록단렬대
InSAR%coseismic deformation%Damxung%Yadong-Gulu rift,southeastern piedmout of the Nyainqentanglha Mountains
利用3景Envisat雷达遥感图像,获取了2008年10月6日西藏当雄\%M\%s6.6地震的震前及同震形变场,结果表明,震前4个多月震中区未出现显著的地壳形变,只是地震造成震中区(20 km×20 km范围)最大近0.3 m的明显变形.形变场近南北轴向对称分布,西部沉降,东部隆升.利用均匀弹性半无限位错模型和约束非线性优化算法,对断层的位错量及分布的估算表明,地震以正断破裂为主,断面最大位错达3 m, 震中位于90.374°E, 29.745°N,震级\%M\%w6.35;地震发生在走向189°、倾角60°的念青唐古拉山南东麓断裂带南段的次级断层上,发震断层长12 km,宽11 km,深度9.5 km,以东西向拉伸运动为主.较浅的震源深度与断层附近的地壳热状态有关.
利用3景Envisat雷達遙感圖像,穫取瞭2008年10月6日西藏噹雄\%M\%s6.6地震的震前及同震形變場,結果錶明,震前4箇多月震中區未齣現顯著的地殼形變,隻是地震造成震中區(20 km×20 km範圍)最大近0.3 m的明顯變形.形變場近南北軸嚮對稱分佈,西部沉降,東部隆升.利用均勻彈性半無限位錯模型和約束非線性優化算法,對斷層的位錯量及分佈的估算錶明,地震以正斷破裂為主,斷麵最大位錯達3 m, 震中位于90.374°E, 29.745°N,震級\%M\%w6.35;地震髮生在走嚮189°、傾角60°的唸青唐古拉山南東麓斷裂帶南段的次級斷層上,髮震斷層長12 km,寬11 km,深度9.5 km,以東西嚮拉伸運動為主.較淺的震源深度與斷層附近的地殼熱狀態有關.
이용3경Envisat뢰체요감도상,획취료2008년10월6일서장당웅\%M\%s6.6지진적진전급동진형변장,결과표명,진전4개다월진중구미출현현저적지각형변,지시지진조성진중구(20 km×20 km범위)최대근0.3 m적명현변형.형변장근남북축향대칭분포,서부침강,동부륭승.이용균균탄성반무한위착모형화약속비선성우화산법,대단층적위착량급분포적고산표명,지진이정단파렬위주,단면최대위착체3 m, 진중위우90.374°E, 29.745°N,진급\%M\%w6.35;지진발생재주향189°、경각60°적념청당고랍산남동록단렬대남단적차급단층상,발진단층장12 km,관11 km,심도9.5 km,이동서향랍신운동위주.교천적진원심도여단층부근적지각열상태유관.
Three scenes Envisat-1 images from ESA were used to derive the pre-seismic and coseismis deformation interfereograms caused by the Damxung Ms6.6 earthquake on Oct. 6, 2008, constrained by InSAR. The results indicate that InSAR could not detect notable crustal motion more than 4 months before the event which caused distinct displacement in an area of 20 km×20 km with a maximum LOS change about 0.3 m. The deformation field was symmetrically distributed and separated by a NS axis, where the west subsided and the east rose. We used a linear elastic dislocation model in half space and nonlinear constraint optimized algorithm to estimate the dislocation value and distribution of the fault. The results indicate that the epicenter locates at E90.374°, N29.745° with a seismic moment tensor Mw6.35. The earthquake is dominated by a normal fault fracture with the maximum slip of 3m on the 12 km×11 km rupture surface striking S189°W, dipping 60°to NW at the bottom of 9.5 km, located at a sub-fault of the southeastern piedmout of the Nyainqentanglha Mountains. The seismic fault extensionally moves along EW. The shallow depth of epicenter is related to crust thermal status of seismic region.