What will the weather and environment around us be like before the earthquake?

Is there a precursor to the earthquake?

Various abnormal phenomena closely related to the occurrence of earthquakes before earthquakes are called earthquake precursors. Therefore, the earthquake is a precursor. Earthquake precursors are divided into macro precursors and micro precursors. Macroscopic precursors refer to those that people can directly feel or see with their eyes, including abnormal reactions of animals and things, groundwater changes, meteorological changes, small earthquake activities and so on. Microscopic precursors refer to those that people can't directly see or feel, but can only be measured by instruments, such as crustal deformation, ground tilt and sea level fluctuation, changes in chemical composition of groundwater, changes in propagation speed of seismic waves, weak changes in geoelectricity, geomagnetism, ground temperature and geostress, and small earthquake activities that people can't feel.

Before an earthquake, especially before a strong earthquake, there will always be some climate and weather anomalies. Such as thermal anomalies, are very obvious before some earthquakes. 17.3 days before the Xingtai earthquake on March 8, 1966, the average temperature rose from-0/3 degrees to 1 1 degrees above zero. Ten days before Haicheng1February 4, 975 earthquake with magnitude 7.3, it was 3.7 degrees higher than the same period of last year. The explosive temperature rise from 8: 00 to 9: 30 12 degrees on the day of the impending earthquake made the cold winter sultry.

This abnormal phenomenon is due to the fact that the earthquake-prone area is on the eve of the violent change of the crust, and before the rupture, the underground heat energy has been violently diffused and transported to the atmosphere by some means. This thermal anomaly has a small range and a short duration.

Some experts have come to the conclusion that in a certain period of time one year or several years before the earthquake, drought first followed by waterlogging, or flood followed by drought; Or drought and flood alternate, followed by a big earthquake. Such earthquakes occur both at home and abroad, such as the Nantong earthquake of 1970. In the first two or three years, a once-in-a-century flood occurred, which triggered a major flood, and then a rare drought occurred. 1989 alternating drought and flood occurred before Daming earthquake in Hebei province. Other phenomena include strange wind, lewd rain, yellow dust and atmospheric turbidity before the earthquake.

There will be a variety of macro anomalies before the earthquake, which has been confirmed by a large number of earthquake activities. How to identify is a complex problem. Generally speaking, there are weather factors (such as fish floating and frog migration), physiological factors (such as animal illness and estrus), environmental factors (such as water pollution), enemy invasion and so on. Non-seismic groundwater anomalies are caused by natural factors, including meteorological, hydrological, geological and biological interference factors. Human factors include irrigation, water injection and drainage. Non-earthquake plant abnormal factors include plant diseases and insect pests and meteorological anomalies. The characteristics of macroscopic anomalies before earthquakes are as follows: firstly, they are not caused by the above non-seismic factors; Secondly, macro anomalies are regular, spatially controlled by geological structures, synchronized in time, and have a wide range of types and a large number. Of course, if the earthquake is abnormal, it must be determined by combining the change of seismic activity and other microscopic precursor monitoring means.