1947年青海达日7(3)/(4)级地震

ON THE DARI EARTHQUAKE OF 1947 IN QINGHAI PROVINCE

摘要:

1947年3月17日青海省达日地震发生在巴颜喀拉山北缘山区,震中烈度为10度,等震线长轴方向为北50°西,地震形变带长150公里,由一系列的陡坎、鼓包、凹槽和裂缝组成。从形变带的性质及其组合规律分析,震区主压应力方向为北东东-南西西。
地震形变现象与挽近时期活动的北50°西的日查-克授滩断裂和北北西向断裂带的展布相一致。因此推断,此次地震是日查-克授滩断裂和北北西向断裂带现今继承性活动的结果。

Abstract:

On March 17,1947, an earthquake of magnitude 7(3)/(4) occurred in the Dari area of Qinghai province. The epicentre was in the North border district of the Bayankalashan Mountain range. The intensity of the epicentre area is X. The direction of the long axis of the equiseismic line was N 50°W.The deformation band of the Dari earthquake was 150 km long. It consisted of a series of fault scarps, little upheavals, little segs and fissures and fractures. Having analysed characteristics of deformation band and composite laws of various deformation phenomena, the author judged that the direction of major compressional stress of earthquake province is NEE-SWW.
The trend and distribution of deformation band of this earthquake was in conformity with the Richa-keshoutan fractures of N50°W and fractures of NNW. Therefore, the cause of occurrence of this earthquake was the result of movement of the Richa-keshoutan fractures and NNW fracture, which still continues at present.