Before the earthquake, the phenomena related to earthquake preparation in nature are called earthquake precursors. In the long-term practice, the ancients in China have long recognized that earthquakes are precursors, and left rich records of earthquake precursors. For example, after the 1739 Yinchuan earthquake in Ningxia, it was inferred that there might be some relationship between the earthquake and well water changes, animal uneasiness, underground sound before the earthquake and abnormal weather phenomena.
Six kinds of earthquake precursor phenomena summarized by the ancients are recorded in the ancient book Lund County Records. Modern earthquake
science
In-depth research shows that there are indeed various precursor phenomena before the earthquake. Earthquake precursors are divided into macro precursors and micro precursors.