摘要
本文论述了澜沧、耿马M_s7.6和7.2级地震的环境因子、地震学和定点前兆等方面中期异常及其综合特征。异常的时序特征表现为:环境因子的气压、涝—旱等异常出现最早,多在震前3—2年;85％的地震学和定点中期前兆异常出现在震前2.5—0.5年;中期异常大量涌现的同时,震源区小震条带开始形成,表明大量的中期异常与震源及附近地区进入不稳定形变带的形成阶段有关。异常的空间分布表明,条带、空区、b值、震源参数及气压、降水等主要异常集中在震源及附近地区;但震中距100 km范围内无定点中期异常显示;水氡、水位、水温等异常仍显示出近源区异常开始早、持续时间长的特点。上述特征有助于未来发震时间和地点的判断。
This paper discussed the medium-term anomalies and their comprehensive features of the environmental factor, seismology and fixed-point precursors of Lancang M 7.6 and Gengma M 7.2 earthquakes. The abnomal time-sequence features are expressed as the following: (1) environmental factors, such as air pressure and flood-draught anomalies appeared at the earliest stage mostly 2-3 years before the event; (2) 85% seismological and fixed-point medium-term precursory anomalies appeared 2.5-0.5 years before the event; (3) while a great number of medium-term anomalies appear, small earthquake bands began to be formed in the source region, showing that the medium-term anomalies are related to the formation stage of the source region and its vicinity entering unstable deformation belt. The spatial distribution of anomalies show that the main anomalies of the band, gap, b-valeu, source parameter, air pressure and precipitation are concentrated in and around the source region. No fixed-point medium-term anomalies appearred in the range 100 km from the epicentre. The water radon, water level and water temperature anomalies are still characterized with earlier appearance in the area closed to the soure and longer duration. The features mentioned above are useful to estimate the future time and location of earthquake occurrence.
出处
《地震》
CSCD
北大核心
1992年第4期18-27,共10页
Earthquake
