青藏高原北部地区地震基本活动状态定量评价  

Quantitative Estimating Basic State of Seismicity in Northern Region of Qinghai-Xizang Plateau

作　　者：刘小凤 梅秀苹 冯建刚 程建武 张辉 

机构地区：[1]甘肃省地震局,甘肃兰州730000

出　　处：《西北地震学报》2011年第2期130-136,共7页Northwestern Seismological Journal

基　　金：地震行业科研专项(200708020);中国地震局兰州地震研究所论著编号:LC2011027

摘　　要：基于区域构造背景、应力场状态及动力学环境等,将青藏高原北部地区划分为4个相对独立的统计单元,即祁连山地震带、甘东南地区、柴达木-共和地块及库玛地震带。通过地震频度和b值拟合确定了各个地区不同下限震级的地震目录完整性起始时间;确定了各构造单元中强以上地震活跃与平静交替活动的特征;定量计算了在平均状态中强以上地震活动特征参数及平静阶段与活跃阶段地震活动特征参数;分别获得了各个区域在平均、活跃与平静状态下的小震活动状态参数。The northern region of Qinghai-Xizang plateau is divided into four separated seismicity areas according to the regional geological structures,stress field and dynamic environment,they are Qilian mountain seismic belt,southeastern Gansu province,Caidam-Gonghe block and Kuma seismic belt.The starting times for the minimum earthquake magnitude with complete recording catalogue in every areas are confirmed on the base of b-value and seismic frequency.The alternative characteristics of active and calm periods for moderate-strong earthquakes in each area are concluded.Finally,the quantitatively characteristic parameters of earthquakes activity which have magnitudes bigger than moderate-strong event in average,active and calm periods are calculated separately,and also the state parameters of small event activity in three periods are obtained for the four areas.

关 键 词：青藏高原北部地区 地震活动状态 定量分析 状态参数 

分 类 号：P315.5[天文地球—地震学]