The number above the beginning of each trace is the source azimuth and below is the epicentral distance.

每条轨迹起点上的数字是震源方位角与震源深度。

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The faults of the strong aftershocks were traced from epicentral distribution of these smaller aftershocks.

强余震的断层是依靠这些小余震的震中分布来描绘的。

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These facts show that before the earthquakes, deformations of the earth crust in the epicentral regions had already occurred.

这些事实说明了大地震发生前震中区的地层已有变形。

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