摘要
总结了2003 年大姚6.2 级地震云南模拟与数字化形变变化的短期异常特征。由模拟形变观测资料显示倾斜单分向加速变化显著,震前均出现转折变化; 地应力阶变及大幅度波动为震前异常形态,而重力没有异常出现。异常展布距震中97~346 km, 异常台站比(距震中400km范围)为35.7%。数字化形变的9个测项中, 楚雄倾斜和应变最为显著, 尽管与降雨影响有关, 但仍认为具有短期前兆意义。
This paper summarized the short-term anomalous characteristics of simulated and numeralized deformation before the Dayao M_S6.2 earthquake, 2003 in Yunnan Province. Simulated deformation tilt one-way data demonstrated the obvious expediting change and turning change; crustal stress demonstrates step change and big amplitude motion change before the earthquake; gravity has not shown anomaly. Anomalous distribution is 97 km to 346 km from the epicenter. The anomalous station ratio (within distance of 400 km from the epicenter) is 35.7%. Among 9 observation items of numeralized deformation, tilt and crustal stress at Chuxiong station show outstanding change, though it is impacted by rainfall, it still has short-term precursory significance.
引文
[1] 刘仲全.姚安6.5级地震前云南倾斜场变化特征[J].地震研究,2001,24(4):301306.
[2] 姜葵.1988年云南澜沧耿马地震[M].昆明:云南大学出版社,1993.