Most seismologists assume that following a major earthquake and its aftershocks, the fault (a break in Earth's crust where pressure can trigger an earthquake) will remain quiet until stresses have time to rebuild, typically over hundreds or thousands of years. Recent evidence of subtle interactions between earthquakes may overturn this assumption, however. According to the stress-triggering hypothesis, faults are unexpectedly responsive to subtle stresses they acquire as neighboring faults shift. Rather than simply dissipating, stress relieved during an earthquake travels along the fault, concentrating in sites nearby; even the smallest additional stresses may then trigger another quake along the fault or on a nearby fault. Although scientists have long viewed such subtle interactions as nonexistent, the hypothesis has explained the location and frequency of earthquakes following several destructive quakes in California, Japan, and Turkey.