1976年唐山7.8级地震前气象要素的异常变化

系统研究了唐山地震前气象要素的异常变化。地震前约一个月时间，震中及附近地区月平均气压变化幅度最大，月平均气压距平中心区域与震中区吻合，沿区域构造带方向出现气压变化最大梯度区，临震前几天气民较大幅度的升、降变化过程，升压脊 区域构造瞳向吻合。地震前一年，丰润、唐山一带年平均气温距平值最大，地震前一天，气温２４小时变温的升温中心在唐山，升温脊受区域构造带控制。０．８ｍ地温亦有明显的升温异常变化。１９７

ABNORMAL VARIATIONS OF METEOROLOGICAL ELEMENT BEFORE THE TANGSHAN M7.8 EARTHQUAKE

This paper systematically studies anomalous change of meteorological element before the Tangshan earthquake. About one month before the earthquake, the change of monthly average atmosphere was the largest in the earthquake region and around it, the anomaly center region of the monthly average atmosphere coincides with the earthquake region, there was the largest gradient region of atmosphere change along the regional tectonics. Several days before earthquake, there was a variational process of large amplitude rise or fall in the atmosphere, and the axis of crest line of rise atmospheric pressure coincides with the strike of regional tectonics. One year before the earthquake, the anomalous value of atmosphreic temperature was the largest in Tangshan-Fengrun zone. One day before the earthquake, Tangshan was the t6mperature rise center of temperature change of 24 hours in the atmosphere temperature and regional tectonics zone was under the control of the crest of the atmospheric temperature. There was obvious anomaly of temperature rising in the geotemperature at depth of 0. 8m. Yutian-Tangshan zone was the largest temperature rising center in average anomaly of geotemperature in the second half of 1975. Up to May of 1976, of all the meterological stations between Qinhuangdao and Handan, Tangshan saution showed the largest amplitude in relative rising temperature in every month. At Tangshan Station etC, the geotemperature of 1975 was the highest from 1957 to 1980, anomaly of geotemperature was the positive anomaly of successive eighteen months from January 1975 to June 1976. The shallow layer geotemperature increased with depth in March 1976, but it decreased with depth in the same month of other years, and this has shown that heat came from depth of crust before the Tangshan earthquake.