In this paper,the distributive regularity of more than 680 hot springs and the epicenters of 40 great earthquakes of magnitude ≥ 7,the relation bet-ween hot springs of different origins and new tectonism in Shanxi,Gans-u,Ningxia,Sichuan,Yunnan,are statistically discussed.It is found that the great earthquakes usually took place near or in the edge of a locality rich in hot springs.
The authors have preliminarily researched the causes closely related the epicenters to hot springs from the earth releasing energy,tectonic motion and the model of the formation of earthquakes.It is considered rea-lative to thermal stress at depth because underground temperature of a loc-lity rich in hot springs is higher,plasticity of rock is greater and rock is easier to break and it is a regulative unit under regional stress.And owing to the fact that local thermal stress proceeded from the difference of temperature at depth in horizontal direction adds up to regional stress,and tremendous stress is accumulated in the locality where the temperature of rock is lower and its intensity is greater (accumulate unit)。Therefore,the great earthquake occurs.