COMPARATIVE ANALYSIS ON THE PRECURSORY ANOMALIES OF GROUNDWATER TEMPERATURE FOR REMOTE STRONG EARTHQUAKE AND THUNDER INTERFERENCE IN NINGBO SEISMOSTATION

The water temperature anomalies in Ningbo Seismostation before Hokkaido M8 earthquake of Japan are compared with thunder interferences.After analysis to the shape of anomaly curve, duration and maximum value we concluded that it is hard to distinguish the anomaly from strong thunder interferences.Thus, in order to exclude interference and catch imminent precursor, we must know the observation data fairly well.