1477年银川地震考证研究

Textual Researches for 1477 Yinchuan Strong Earthquake

1477年5月13日银川一带发生强烈地震,地震处于沙漠边缘,故史料记载不够详细。此次地震有限的地震史料,结合前人研究的历史地震震级估计和烈度衰减经验公式及相关的地震资料,通过估算和对比方法重新分析研究1477年地震的震级和震中。建议此次地震震级应为M7,震中位置为民勤东130 km处,而银川和张掖的地震烈度分别取值为Ⅶ和Ⅵ度。结合新建议的震中位置,简单讨论这次地震发生的构造条件。

A strong earthquake occurred in the region of Yinchuan on the May 13,1477.Due to the earthquake happened at the edge of Tenggeli desert,which is a desolate and uninhabited place,his-torical records about this earthquake is limited.On the basis of historic documents,the magnitude of this strong earthquake was examined to be M = 6 ？？？,the epicenter of the west of Yinchuan （38.5＆#176;N）,106.3＆#176;E,the epicentral intensity of Yinchuan was Ⅷ in all previous publication of the catalogues of earthquake in China.However,some experts have questioned the identification re-sults,we also have problems with the magnitude and epicenter.In the paper,based on the same historical earthquake data,we use the empirical formula for estimation of seismic magnitude and elliptical attenuation of seismic intensity and some interrelated modern earthquake data;by the methods of estimating and comparing,we reanalyze the magnitude,it’s epicenter and the seismic intensity of several region of the 1477 strong earthquake.In our opinion,we recommend that the magnitude of the earthquake should be identified as M =7 1/4 ,the epicenter should be located in the east of Minqin（38.40°N,104.36°E）.In addition,the epicentral intensity of Yinchuan is advised to be Ⅶ,and Zhangye is Ⅵ.Finally,combining with the proposal epicenter location,we simply discuss the seismogenic tectonic background of 1477 earthquake.