Because P and S waves travel at different but fairly constant speeds, the interval between their arrivals increases in proportion to the distance from the earthquake focus, or initial rupturepoint.
由于 P 波和 S 波以不同但相当恒定的速度传播，它们到达的间隔与到震源或初始破裂点的距离成比例地增加。
2
This is considered a point of pre-rupture, since it is a matter of time before effort is abandoned.
这是关系破裂的临界点，因为没有努力的支撑，其迟早要发生。
3
Their faults are often very complex and slow-moving, sometimes taking hundreds or even thousands of years to build up tension to the point where they rupture.