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海城地震前后重力重复测量结果表明:在极震区及其附近地区重力场发生了显著的有规律性的变化. 1972年6月建立北镇—庄河重力复测剖面开始重力观测,同年11月及1973年5月进行了两次复测,发现辽东半岛地区重力场减小,最大达-352微伽.1975年3月震后进行了第一次复测,重力场却已基本回升到1972年6月建点时的水平.7月份再次复测,其结果表明重力场继续升高,最大达+382微伽.其后直至1976年12月多次进行复测,重力场基本保持在1975年7月的水平.因此,震中区震前重力场下降、震后上升的特征相当清楚. 通过对工作方法和观测精度的分析,说明重力测量成果是可靠的,重力场变化的原因与地震的孕育过程有着密切关系.
Repeated gravimetric measurements before and after the Haicheng earthquake show that significant and regular changes have taken place in the gravity field in and around the earthquake area. In June 1972, a gravity survey was started to establish the gravity survey of the North Town-Zhuanghe Gravity Reanalysis Section. In the same year, Month and May 1973. It was found that the gravitational field in Liaodong Peninsula decreased to a maximum of -352 microgas and the first retest was conducted after the earthquake in March 1975. The gravitational field has basically recovered to The level at the time of the establishment of the site in June 1972 was retested again in July and the results showed that the gravitational field continued to rise up to a maximum of +382 microgas and subsequently retested several times until December 1976. The gravitational field basically remained at July 1975. Therefore, the characteristics of the gravitational field decreasing and post-earthquake rising are quite clear before the earthquake.The analysis of working methods and observation precision shows that the gravimetric results are reliable, and the reason of the gravitational field changes is similar to that of earthquakes The breeding process is closely related.