地震地磁观测与研究
地震地磁觀測與研究
지진지자관측여연구
SEISMOLOGICAL AND GEOMAGNETIC OBSERVATION AND RESEARCH
2015年
2期
6-12
,共7页
宫悦%龙锋%乔慧珍%赵敏%王宇玺
宮悅%龍鋒%喬慧珍%趙敏%王宇璽
궁열%룡봉%교혜진%조민%왕우새
视应力%应力降%震级%地震矩%时空分布
視應力%應力降%震級%地震矩%時空分佈
시응력%응력강%진급%지진구%시공분포
apparent stress%stress dropping%earthquake magnitude%seismic moment%spatial-temporal variation
利用四川数字地震台网记录资料,计算2008年汶川地震后,川东南地区ML 3.0以上地震的震源动力学参数特征,分别得到视应力、应力降与震级之间、震级和地震矩之间,以及地震矩和视应力之间的定标关系。通过扣除震级影响,计算归准化视应力值的时空变化特征。得到结果如下:①从时间分布图来看,研究区4级以上地震频发时段刚好对应视应力涨落较明显时段,而该时段当地工业采矿注水活动强烈,故该区域视应力水平或许反映了工业活动对区域应力场的影响;②从空间分布图来看,自贡隆昌一带震级偏大,视应力反而偏小的现象可能与该区域应力释放不充分、构造应力水平偏低有关,未来要关注该区域发生中强地震的可能。
利用四川數字地震檯網記錄資料,計算2008年汶川地震後,川東南地區ML 3.0以上地震的震源動力學參數特徵,分彆得到視應力、應力降與震級之間、震級和地震矩之間,以及地震矩和視應力之間的定標關繫。通過釦除震級影響,計算歸準化視應力值的時空變化特徵。得到結果如下:①從時間分佈圖來看,研究區4級以上地震頻髮時段剛好對應視應力漲落較明顯時段,而該時段噹地工業採礦註水活動彊烈,故該區域視應力水平或許反映瞭工業活動對區域應力場的影響;②從空間分佈圖來看,自貢隆昌一帶震級偏大,視應力反而偏小的現象可能與該區域應力釋放不充分、構造應力水平偏低有關,未來要關註該區域髮生中彊地震的可能。
이용사천수자지진태망기록자료,계산2008년문천지진후,천동남지구ML 3.0이상지진적진원동역학삼수특정,분별득도시응력、응력강여진급지간、진급화지진구지간,이급지진구화시응력지간적정표관계。통과구제진급영향,계산귀준화시응력치적시공변화특정。득도결과여하:①종시간분포도래간,연구구4급이상지진빈발시단강호대응시응력창락교명현시단,이해시단당지공업채광주수활동강렬,고해구역시응력수평혹허반영료공업활동대구역응력장적영향;②종공간분포도래간,자공륭창일대진급편대,시응력반이편소적현상가능여해구역응력석방불충분、구조응력수평편저유관,미래요관주해구역발생중강지진적가능。
This paper obtains the following scaling relations after calculating the seismic source dynamically parametric features of earthquakes aboveML3.0, which were observed in southeast Sichuan after Wenchuan earthquake by using the digital seismic data by Sichuan Seismic Network. Those scaling relations are:①Apparent stress &earthquake magnitude.②Stress dropping & earthquake magnitude,③Earthquake magnitude & seismic moment. ④Seismic moment & apparent stress. Based on the above relations, it further calculates features of spatio-temporal changes whose apparent stress is normalized, and thus reaches the following conclusions.①In the viewpoint of temporal distribution, earthequake-prone periods of researched zone ofML≥4.0 earthquakes happen to correspond to periods whose fluctuation of apparent stress is evident. Local intense mining water injection happened to be in the same time. Thus, the apparent stress level of researched zone might refl ect the industrial activity impact on the regional stress fi eld.②In the viewpoint of the spatial distribution, the reason why Zigong-Longchang area has larger magnitude whereas its apparent stress is relatively small might attribute to its insuffi cient release of apparent stress and low tectonic stress level. Special attention should be paid to the probable strong earthquake in this area.