2022年地震活动综述

Summary of Earthquake Activities in 2022

归纳性综述了2022年全球到局部尺度的地震活动,讨论了全球、中国内地及其邻区、四川及其邻区地震活动的概况和特征;记叙了四川区域内发生的突出地震事件;追踪了近年四川区域内已发强震的几个余震区余震衰减活动情况。结果显示:(1)全球大震活动分布不均,呈现北半球弱、南半球强的活动差异,欧亚地震带异常平静、频次和强度均弱的特征。(2)中国内地及邻区地震活动分布集中、频次高、强度弱,M_(S)≥5.0地震主要集中分布在青藏地块,其次分布在西域地块。(3)四川及邻区地震活动受块体活动调整控制,尤其受巴颜喀拉地块的调整活动控制,呈现频次和强度均高于上一年度的特点。(4)四川境内突出地震有4次,兴文M_(S)5.1地震发生在长宁—珙县—筠连—兴文区域,位于川东南地震重点监视跟踪工作区;芦山M_(S)6.1地震是一次紧邻2013年芦山M_(S)7.0地震的新强震破裂,与芦山M_(S)7.0地震分属不同破裂面;马尔康M_(S)6.0震群属多断层面触发性震群;泸定M_(S)6.8地震属于发生在鲜水河断裂东南段的磨西断层段的左旋走滑破裂事件。历史余震区余震活动显示:2008年汶川M_(S)8.0地震整个余震区余震仍持续活动,强度衰减明显;2019年长宁M_(S)6.0地震余震区余震仍持续活动,强度减弱而频次依然较高;2013年芦山M_(S)7.0和2017年九寨沟M_(S)7.0两地震余震区的余震强度和频次均明显减弱。

The global to local seismic activities in 2022 are summarized in this paper.The general situations of seismic activity in the world,China and neighboring regions,and Sichuan and neighboring regions are presented.The characteristics of seismic activity in the world,China and neighboring regions and Sichuan and neighboring regions are discussed.Salient events occurred in Sichuan region are recorded.In recent years,the aftershock attenuation activities in several aftershock areas where strong earthquakes have occurred have also been tracked.The results show that:The characteristics of uneven distribution of large earthquakes,abnormal calm of Eurasian seismic belt,low frequency and weak intensity are shown by global large earthquake activities.At the same time,global seismic activities show that seismic activities in the northern hemisphere are weaker than that in the southern hemisphere.The characteristics of concentrated distribution,high frequency and weak intensity are shown by the seismicity in Chinese Mainland and its adjacent areas.The Qinghai Tibet block is the main active area of strong earthquakes in Chinese Mainland and its adjacent areas.The M_(S)≥5.0 earthquakes are mainly distributed in the Qinghai-Tibet block,and also partially distributed in the western block.The earthquakes in Sichuan and its adjacent areas are controlled by the adjustment of block activities,especially the adjustment of the Bayan Har block.The characteristics of high earthquake frequency and stronger than that of the previous year are shown in Sichuan and its neighboring regions.Salient earthquakes in Sichuan include:The M_(S)5.1 Xingwen earthquake,which occurred in Changning-Gongxian-Junlian-Xingwen region,is located in the key earthquake monitoring and tracking work area in southeast Sichuan.The Lushan M_(S)6.1 is a new strong earthquake rupture close to the 2013 Lushan M_(S)7.0 earthquake,which is different rupture plane from the 2013 Lushan M_(S)7.0 earthquake.The M_(S)6.0 Ma’erkang earthquake swarm belongs to multi-fault triggering earthquake swarm.The M_(S)6.8 Luding earthquake occurred in the left-lateral strike-slip rupture event of the Moxi fault segment in the southeast section of the Xianshuihe fault.The aftershocks in the whole aftershock area of the M_(S)8.0 Wenchuan earthquake in 2008 continued to be active,with obvious intensity attenuation.The aftershocks of the M_(S)6.0 Changning aftershock area in 2019 continued to be active,the intensity weakened and the frequency remained high.The intensity and frequency of the aftershocks in the two aftershock areas of the M_(S)7.0 Lushan earthquake in 2013 and the M_(S)7.0 Jiuzhaigou earthquake in 2017 are significantly weakened.