宁夏几次中强地震与重力变化特征

MODERATELY STRONG EARTHQUAKES AND GRAVITY ANOMALY CHARACTERISTICS IN NINGXIA REGION

对宁夏地震重力测网１９８７年以来的野外观测数据进行了统一平差处理和精度评定。给出了判断重力非潮汐异常的标准，并对各期重力平差资料进行了判别。结果表明：宁夏境内中强地震前１年内可观测到重力异常变化，异常特征是正异常。

The mobile gravity observation data in Ningxia region are adjusted and their accuracy are evaluated. The judgement standard of seismic gravity anomaly is obtained, by which the adjustment data of each observation are judged. It is shown that the gravity anomaly variations within one year before the earthquake are observed. The characteristcs of gravity variation is positive anomaly, and the earthquakes are occurred in the rising region or the hinterland of the gravity variation. These characteristics can be referred for earthquake prediction and research.