四川地震
四川地震
사천지진
EARTHQUAKE RESEARCH IN SICHUAN
2014年
2期
12-15
,共4页
芦山地震%汶川地震%静态库仑应力
蘆山地震%汶川地震%靜態庫崙應力
호산지진%문천지진%정태고륜응력
Ms7. 0 Lushan Earthquake%Ms8. 0 Wenchuan Earthquake%Coulomb stress
2013年4月20日在四川芦山发生了Ms7.0地震,震源深度17 km,发震断层位于龙门山断裂带南段的前山断裂附近,为逆冲断层机制,芦山地震震中位置位于2008年汶川Ms8.0地震西南方向85 km处,两个地震的余震分布区中间存在一个约20~30 km的破裂空段。首先计算汶川地震的静态库伦应力,明确汶川地震对芦山地震的触发影响,芦山地震的发震位置处于汶川地震后的应力加载区域;进一步计算芦山地震对周围的静态库仑应力,结果显示,芦山地震对二者之间破裂空段的影响为应力加载;最后计算汶川地震和芦山地震周围的静态库仑应力的综合影响,二者对川滇交界东部的应力加载作用是明确的,对中间存在的20~30 km的空段也存在一定的应力加载影响。
2013年4月20日在四川蘆山髮生瞭Ms7.0地震,震源深度17 km,髮震斷層位于龍門山斷裂帶南段的前山斷裂附近,為逆遲斷層機製,蘆山地震震中位置位于2008年汶川Ms8.0地震西南方嚮85 km處,兩箇地震的餘震分佈區中間存在一箇約20~30 km的破裂空段。首先計算汶川地震的靜態庫倫應力,明確汶川地震對蘆山地震的觸髮影響,蘆山地震的髮震位置處于汶川地震後的應力加載區域;進一步計算蘆山地震對週圍的靜態庫崙應力,結果顯示,蘆山地震對二者之間破裂空段的影響為應力加載;最後計算汶川地震和蘆山地震週圍的靜態庫崙應力的綜閤影響,二者對川滇交界東部的應力加載作用是明確的,對中間存在的20~30 km的空段也存在一定的應力加載影響。
2013년4월20일재사천호산발생료Ms7.0지진,진원심도17 km,발진단층위우룡문산단렬대남단적전산단렬부근,위역충단층궤제,호산지진진중위치위우2008년문천Ms8.0지진서남방향85 km처,량개지진적여진분포구중간존재일개약20~30 km적파렬공단。수선계산문천지진적정태고륜응력,명학문천지진대호산지진적촉발영향,호산지진적발진위치처우문천지진후적응력가재구역;진일보계산호산지진대주위적정태고륜응력,결과현시,호산지진대이자지간파렬공단적영향위응력가재;최후계산문천지진화호산지진주위적정태고륜응력적종합영향,이자대천전교계동부적응력가재작용시명학적,대중간존재적20~30 km적공단야존재일정적응력가재영향。
The Ms7. 0 Lushan Earthquake on 20 April 2013,Sichuan Province,resulted from a north-south striking fault with reverse-type motion. This event occurred on the southern part of Longmenshan fault. The epicenter of the Ms7. 0 Lushan Earthquake locates southwest 85 km from the Ms8. 0 Wenchuan Earthquake on 12 May 2008. There is a seismic gap segment with 20 to 30 km long along the main rupture fault between two earthquake groups. In this study,we calculated the Coulomb stress change induced by the Ms8. 0 Wenchuan Earthquake at first and then find that the Ms7. 0 Lushan Earthquake was induced by the Ms8. 0 Wenchuan Earthquake. Our analysis results show the Ms7. 0 Lushan Earthquake epicenter is located in the increasing region of Coulomb stress after the Ms8. 0 Wen-chuan Earthquake. Then we calculate the Coulomb stress change caused by the Ms7. 0 Lushan Earthquake and find that the influence of the Ms7. 0 Lushan Earthquake on the gap segment results from the increasing of Coulomb stress. Furthermore we calculated the stress change of the region nearby induced by both the Wenchuan and the Lushan earthquakes. The Coulomb stress of the eastern border between Sichuan and yunnan provinces has been in-creased as well.