At 5:36 P.M., something snapped along the fault lines beneath the waters of Unakwik Inlet. The resultant shock waves spread in all directions—heaving islands upward, sucking lakes dry, and violently shaking ridgelines and valleys. For three to four minutes the rumbling continued. Registering between 8.4 and 8.7 on the Richter scale, Alaska’s Good Friday earthquake was the most powerful seismic event ever recorded in North America.
