摘要
龙陵 -澜沧新生断裂带的地震活动具频度高、强度大、周期短等特征 ,并以双震或震群型为主。断裂带由多条次级新生断层组成 ,呈斜列或共轭式展布 ,根据结构、规模、地震活动差异等因素把断裂带划分为 4个一级段、13个二级段 ,其中有 4个二级段又可划分出 8个三级段。历史上发生过大震、强震并有地震断层伴生的断层段为地震破裂单元 ;断裂带上晚第四纪有活动并有古地震事件 ,但无历史地震记载的地段为断层闭锁单元 ;次级断层之间的阶区或连接点为障碍体单元。从地震破裂特征分析 ,断裂带由破裂、闭锁、障碍体单元组成 ,根据地震、古地震、活断层、断层阶区的活动规律 ,断裂带可划分出 9个破裂单元、8个闭锁单元、10个障碍体单元。三者之间呈迁移、触发和转换能量的关系。根据这些关系和地震构造标志 ,对断裂带上未来可能发生大震、强震、中强震的地区分别作了预测。预测的危险区有 9个 ,其中大震区 1个 (永康 -永德地区 ) ,强震区 3个 (马站、石灰窑、酒房-勐混 ) ,中强震区 5个 (下顺江、里仁、大岗山、南明 -澜沧、勐遮 )。
Longling Lancang fault zone, consisting of sets of en echelon or conjugated short faults, is a newly generated rupture zone. It is characterized by high frequency, large magnitude, and short recurrence interval of earthquake activity, as well as by double main shock earthquake or earthquake swarm. The fault zone can be naturally divided into 4 first order segments and 13 secondary earthquake rupture segments, among which 4 segments can be further divided into 8 third order segments according to the differences in their internal geometry, fault length and seismicity. Generally speaking, the fault segment, on which large or strong earthquake occurred in history can be defined as earthquake rupture unit, while the segment on which the fault was active in Late Quaternary but no earthquake is recorded in history can be defined as locked element. The stepover or connecting structure between the faults is named as the barrier. In terms of the rupture pattern of historical earthquakes and paleoseismicity, the fault zone can be divided into 9 surface rupture units, 8 locked elements and 10 barriers. Surface rupturing earthquake may be transformed, triggered or migrated among these three kinds of units. At last, the risk segments of future large, strong and moderate earthquakes are predicted according to seismotectonic criteria. There are 9 predicted earthquake risk areas, among which one is large earthquake area located between Yongde and Yongkang region, three are strong earthquakes area located at Mazhan, Shihuiyao and Jiufang Menghun regions and five are moderate earthquakes area located at Xia^shunjiang, Liren, Dagangshan, Nanming Lancang and Mengzhe regions, respectively.
出处
《地震地质》
EI
CSCD
北大核心
2002年第2期133-144,共12页
Seismology and Geology
基金
国家重点基础研究发展规划项目 (G19980 4 0 70 1)
地震科学联合基金 (196 0 37)
中国地震局"九五"重点项目 (95 0 4 10 )
