滇西地面水准面的变化与地震发生的研究

A Study On The Ground Level Surface Deformations and Earthquakes in West Yunnan

基于1985~1998年间滇西重复重力测量网的重复测量,首次测定了该地区的非潮汐垂线偏差时变(PLV)和地面水准面变形(GLSD)。利用这些数据研究发生在附近的地震时发现了一个现象:地震前地震中心附近地面水准面隆起,震后下凹。以测定的地面水准面为主线,研究了这一区域的1985~1998年间8次大于4.6级的地震。用地面水准面隆起和下凹的时间变化,来描述地震发生的整个过程。测定了与地震发生有关的地面水准面形状变化,包括尺度、最大高度、最高点所在位置等等。GLSD与地震发生之间的这种巧合型,不仅展示了研究地震的一种新方法的应用,而且也验证了本地区非潮汐垂线偏差时变和大地水准面变形。

Based on the repeated measurements of the gravimetric network in West Yunnan,China during 1985～1998,the non-tidal Plumb Line Variations(PLV) and the Deformations of the Ground Level Surface(GLSD) in this area have been determined for the first time.Interesting phenomena have been discovered by using these measurements to study the earthquakes happening nearby.It appears that there usually exists a raised GLSD around the emerging epicenter before an earthquake,but an opposite GLSD afterwards.Taking the deter...