Science. 1974 Jun 21;184(4143):1281-3. doi: 10.1126/science.184.4143.1281.
Residuals for P-wave traveltimes at a seismnograph station near Bear Valley, California, for small, precisely located local earthquakes at distances of 20 to 70 kilometers show a sharp increase of nearly 0.3 second about 2 months before a magnitude 5.0 earthquake that occurred within a few kilometers of the station. This indicates that velocity changes observed elsewhere premonitory to earthquakes, possibly related to dilatancy, occur along the central section of the San Andreas fault system.
在加利福尼亚州贝尔山谷附近的一个地震仪站，对距离 20 至 70 公里的小而精确定位的局部地震的 P 波传播时间残差进行分析，结果表明，在距离该站几公里范围内发生的 5.0 级地震前约 2 个月，出现了近 0.3 秒的急剧增加。这表明，在地震前其他地方观察到的速度变化可能与扩容有关，这些变化发生在圣安德烈亚斯断层系统的中央部分。
