| 2017年九寨沟地震所受历史地震黏弹性库仑应力作用及其后续对周边断层地震危险性的影响 |
| |
| 引用本文： | 程佳,姚生海,刘杰,姚琪,宫会玲,龙海云.2017年九寨沟地震所受历史地震黏弹性库仑应力作用及其后续对周边断层地震危险性的影响[J].地球物理学报,2018,61(5):2133-2151. |
| |
| 作者姓名： | 程佳 姚生海 刘杰 姚琪 宫会玲 龙海云 |
| |
| 作者单位： | 1. 中国地震台网中心, 北京 100045;2. 青海省地震局, 西宁 810010;3. 广东省地震局, 广州 510070 |
| |
| 基金项目： | 国家自然科学基金（41404043）和中国地震局星火计划项目（XH16044和XH17045）联合资助. |
| |
| 摘 要： | 首先对2017年九寨沟MS7.0地震周边断裂活动和历史地震特征进行了阐述；然后利用黏弹性地壳模型，计算了1933年叠溪地震、1976年松潘震群和2008年汶川地震对2017年九寨沟地震的同震和震后库仑应力作用.该结果显示1933年叠溪地震对九寨沟地震具有延缓作用，而1976年松潘震群和2008年汶川地震对九寨沟地震的黏弹性库仑应力作用为正；随着下地壳和上地幔黏弹性物质的持续作用，前述几次地震总的黏弹性库仑应力在九寨沟地震破裂中心点处负的库仑应力逐渐减弱，而在破裂北段这些库仑应力逐渐转为正值，并促进了九寨沟地震的发生.本文也计算了九寨沟地震后对周边断层的库仑影响，并将此影响值转换为对断层能量积累的影响时间上，结果显示塔藏断裂带西段和中段在内的多条断裂带受到黏弹性库仑应力影响时间值超过10年.将库仑应力影响时间值加入到部分已知离逝时间的断层段上，也得到了这些断层段的未来30年特征地震发生概率.最终结果认为玛沁断裂带、玛曲断裂带、哈南—稻畦子断裂中段和西段等断层段的强震危险性需要重点关注.
|
| 关 键 词： | 2017年九寨沟7.0级地震 东昆仑断裂带尾端 黏弹性库仑应力作用 地震矩积累率 强震危险性概率 |
| 收稿时间： | 2017-09-16 |
Visoelastic Coulomb stress of historical earthquakes on the 2017 Jiuzhaigou earthquake and the subsequent influence on the seismic hazards of adjacent faults |
| |
| CHENG Jia,YAO ShengHai,LIU Jie,YAO Qi,Gong HuiLin,LONG HaiYun.Visoelastic Coulomb stress of historical earthquakes on the 2017 Jiuzhaigou earthquake and the subsequent influence on the seismic hazards of adjacent faults[J].Chinese Journal of Geophysics,2018,61(5):2133-2151. |
| |
| Authors: | CHENG Jia YAO ShengHai LIU Jie YAO Qi Gong HuiLin LONG HaiYun |
| |
| Affiliation: | 1. China Earthquake Networks Center, Beijing 100045, China;2. Qinghai Earthquake Agency, Xining 810010, China;3. Guangdong Earthquake Agency, Guangzhou 510070, China |
| |
| Abstract: | The MS7.0 Jiuzhaigou earthquake in 2017 occurred in a complex tectonic region where the eastern Kunlun fault meets the Longmenshan fault. To study the interactions among the Jiuzhaigou earthquake and historical events in adjacent areas,we first present the slip features of the regional faults and historical records of major earthquakes. Then using the viscoelastic crustal model and historical rupture data,we calculate the coseismic and viscoelastic Coulomb stress changes (ΔCFS) on the seismogenic fault of the Jiuzhaigou earthquake from the MS7.5 Diexi earthquake in 1933,the triplet events in 1976 with two MS7.2 and one MS6.7 earthquakes,and the MS8.0 Wenchuan earthquake in 2008. The results show that the Diexi earthquake in 1933 had negative coseismic effect on the moment accumulation of the Jiuzhaigou earthquake in 2017,while the triplet events in 1976 and the Wenchuan earthquake in 2008 gave the positive coseismic effects. With the continuous viscoelastic effects induced by the lower crust and upper mantle,at the center of the seismogenic fault of the Jiuzhaigou earthquake,the negative ΔCFS has tapered gradually; while at the north end,the ΔCFS has changed from negative to positive,which might have promoted the occurrence of the Jiuzhaigou earthquake in 2017.
To analyze the seismic hazard of the nearby active faults after the Jiuzhaigou earthquake,we calculate the ΔCFS on these faults induced by all the earthquakes aforementioned,including the Jiuzhaigou earthquake. Then we transfer the calculated ΔCFS value to the influenced time of the characteristic earthquake energy accumulation for each fault segment based on the known slip rate. In our results,the ΔCFS values on several fault segments,including the western and the middle segments of the Tazang fault,are equivalent to more than 10 years of influence time on seismic moment accumulation. Adding this influence time to the elapsed time of the characteristic earthquakes on these segments,we obtain the conditional probabilities of the characteristic earthquakes in the next 30 years. Our results indicate that the seismic hazards on the following fault segments are high: the Maqên fault,Maqu fault,and the middle and western segments of the Hanan-Daoqizi fault. |
| |
| Keywords: | MS7 0 Jiuzhaigou earthquake in 2017 Eastern Kunlun fault Viscoelstic Coulomb stress Seismic moment accumulation Probability of seismic hazard |
|
| 点击此处可从《地球物理学报》浏览原始摘要信息 |
|
点击此处可从《地球物理学报》下载全文 |
|
