1977年8月6日01时25分在丹江口水库水域内发生了一次Ms3.8级地震,震中烈度超过Ⅴ度,有感范围近10000平方公里。这次地震既不全同于一般构造地震,又与“标准”的水库地震有明显差别。作者试图在已有资料的基础上,初步阐明这些现象和有关问题,为全面认识水库地震的特点、发生条件和成因机制提供一些线索。 At 01.25 on August 6, 1977, an Ms3.8 earthquake occurred in the Danjiangkou Reservoir watershed and the intensity of the epicenter exceeded Ⅴ degree, with a sense of nearly 10,000 square kilometers. This earthquake is neither identical to a general structural earthquake nor to a “standard” reservoir earthquake. Based on the existing data, the author tries to clarify these phenomena and related problems, and provide some clues for fully understanding the characteristics, conditions and mechanism of reservoir earthquakes.