RELATIONSHIP BETWEEN THE WATER LEVEL ANOMALIES FROM PANZHUANG WELL IN TIANJIN AND EARTHQUAKES

The groundwater observation net in Tianjin covers different aquifer, and salty layers account for a certain proportion.Taking Ninghe Panzhuang salty water well as an example we analyzed the relation of water level anomalies with earthquakes, and summarized the characteristics of the anomalies.The results show that all the anomalies showed a jump-slow drop shape, and can be divided into two types:(1) jump-turning-drop-earthquake;(2)jump-turning-recover-earthquake.The magnitude of jump is usually at about several meters, and it recovers after earthquake.The time of anomaly is not concentrating, but mostly over half year.The magnitude of anomaly increases with the magnitude of earthquake, decreases with the epicentral distance.