2002年腾冲火山区微震观测  

OBSERVATION OF MICROEARTHQUAKES IN TENCHONG VOLCANIC AREA IN 2002

作　　者：蔡绍平[1] 刘学军[1] 叶建庆[1] 蔡明军[1] 

机构地区：[1]云南省地震局,昆明650041

出　　处：《地震地质》2003年第B12期138-146,共9页Seismology and Geology

基　　金：科技部社会公益研究专项资金 (2 0 0 1DIA10 0 0 3)资助

摘　　要：20 0 2年 6月 13日至 9月 13日腾冲火山区流动数字化地震台网记录了腾冲火山区及周边地区的 2 92次地震事件。对资料的初步分析表明 ,在本次观测期间 ,腾冲火山区南部地区火山地震活动仍然频繁 ,以微震为主。选用发生在火山区的 33个地震震源参数计算得出的拐角频率为 4 37～11 87Hz、应力降为 0 0 0 5～ 0 2 77MPa ,显示该区域尚属低应力分布区。S波湮灭图像的再次出现 ,充分表明在腾冲县城西南至热海的马鞍山火山、老龟坡火山一带有岩浆囊熔融体存在的可能 ,深度不超过 10km。文中还展示了台网记录到的S波湮灭、微破裂高频地震、波形特征类似火山颤动 (包络型事件 )This paper introduces the results of micro-earthquake observation by digital mobile seismic observation network disposed in Tengchong volcanic area during the period from June 6 to September 13, 2002. During the observation, 292 seismic events occurred in Tengchong and its peripheral areas had been recorded. The analysis of the obtained data shows that the volcanic earthquake activity in the southern part of Tencgchong volcanic area is still very frequent, appearing mainly as micro-earthquake. Based on the source parameters of 33 seismic events occurred in the area, it is calculated that the corner frequency ranges between 4.37Hz and 11.87Hz, and the stress drop is in the range of 0.005～0.277MPa. This may indicate that this area is still dominated by low stress. The phenomenon of S-wave annihilation may fully evidence the existence of magma pocket at less than 10km depth beneath the Ma'anshan and Laoguipo volcanoes in the area from the southwest of Tengchong County to Rehai. Moreover, various patterns recorded by the network, such as S wave annihilation, micro-fracture high-frequency earthquake, and the waveforms typical of volcanic vibration are presented in this paper as well.

关 键 词：微震观测 S波湮灭 岩浆囊 腾冲火山区 

分 类 号：P317.6[天文地球—固体地球物理学]