【摘要】 华北重力复测网(火车运输)始建于1972～1973年,三环共45个点,1986年起改用高精度LCR G重力仪观测(仍保持三环,点位减到15个),至今已积累了16～33期重复观测资料。根据资料,华北网各测点重力值变化可分为三类,即1.有异常变化点;2.持续相对稳定点;3.重力值有变化,但非深部物质引起或重力值无变化点。如果观测到的异常持续3～5年,且与背景相符,即有可能与中强震有关,并已被实践证明,因此,重力大跨度复测是中长期地震预报的一种有效手段。更多还原

【Abstract】 The repeated surveying network of gravity in Norty China(transported by train),which has 45 points in three loops,was established in 1972 to 1973.Since the application of precision LCR-G gravimeter in 1986(the surveying points rdduced from 45 to 15 in the three loops),it has accumulated 17observations data.The variation of gravity on each point in North China network can be divided into three types:(1)abnormal points,(2)relative stable points(3)there are some change in gravity,but not caused by deep materials.If the anomalies of gravity lasted 3 to 5years,it may have relations with a mid-stronger earthquake.Prediction practice shows that repeated survey of gravity is an effective approach in earthquake prediction.更多还原