摘要
青藏高原是我国现代构造活动和地震活动最强烈的地区，自有地震记录以来，在高原内记录到多达18次8级以上巨大地震和100余次7∽7．9级地震，它们均发生在喜马拉雅板块边界构造带和板内断块区及其次级断块的边界活动构造带上．自1900年有地震仪器记录以来，青藏高原曾经历了3次地震活动丛集高潮，即1920--1937年，1947—1976年和1995-现在．在每次地震活动丛集期都形成以8级地震为核心的7级以上地震活动系列，它们分别是20世纪20-30年代的海原-古浪地震系列、50-70年代察隅-当雄地震系列和20世纪末期以来昆仑-汶川地震系列．每一个地震系列都有自己的主体活动区，最新的昆仑汶川地震系列的主体活动区为巴颜喀喇断块．青藏高原地震活动高潮与全球MW≥8．0巨大地震活动高潮紧密相关，昆仑-汶川地震系列与自2001年至今的全球最新地震活动高潮相对应，它们反映了两者的动力学联系．经过详细对比研究认为，它们至今均仍在延续之中，全球板块边界构造带8∽9级地震和板内大陆断块区的7∽8级地震都仍在连续发生．研究了全球和区域地震活动的相关关系及青藏高原地震活动的时空分布特征，指出了该区当前地震活动的总体形势，评价了其近期地震危险性，提出了加强地震监测的建议．
The Tibetan Plateau is a region with intensive tectonic deformation and high level earthquake activity. On the basis of historical records, there have been 18 earthquakes with magnitude over 8 and more than 100 events with magnitude between 7 and 7.9 in the plateau. All of these events occured either along plate boundary of the Himalaya or along boundaries among the intra-plate fault blocks as well as sub-blocks. There have been three phases of earthquake clustering in the Tibetan Plateau, 1920 to 1937, 1947 to 1976, and 1995 to present, since instrumental seismic records began in 1900. Each phase of the cluster is characterized by events of magnitude over 8 and a number of events of magnitude over 7 to form an earthquake series. The three phases are the Haiyuan-Gulang earthquake series in 1920s to 1930s, the Chayu-Dangxiong earthquake series in 1950s to 1970s, and the Kunlun-Wenchuan series since the beginning of this century. Each earthquake series also has its major active region of occurrences. For example, the major active region of occurrence is associated with the newest phase of earthquake series is the Bayan Har fault block. The episodes of seismic activity in the Tibetan Plateau coincide with the high level activities of global mega-earthquake （MW≥8） activity. The Kunlun-Wenchuan earthquake series concurs with the global earthquake activity since 2001 suggesting geodynamic connections between them. Based on careful comparative studies, we suggest the current phase of earthquake activity continues today giving that the global mega-earthquakes （Mw8-9） occur frequently along plate boundaries and major intra-plate earthquakes （Mw7-8） occur along boundaries of crustal fault block. Through studies of relationships between global and regional earthquake activities and of temporal and spatial distribution of the earthquakes in the Tibetan Plateau, this paper summarized general tendencies of current earthquake activity, assesses recent earthquake potential, and proposes suggestions for intensive ea
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2014年第7期2025-2042,共18页
Chinese Journal of Geophysics
基金
国家科技支撑计划项目"汶川地震断裂带科学钻探"
财政部行政事业类项目"我国地震重点监视防御区活动断层地震危险性评价"资助
关键词
青藏高原
巴颜喀喇断块
地震丛集
主体活动区
全球地震活动高潮
当前地震活动形势
Tibetan Plateau
Bayan Har fault block
Seismic cluster
Major region of seismicity
High level global earthquake activity
Current tendency of seismicity
