Alaska quake produces prolonged shaking, small tsunami Photo: Sarah Knapp/Homer News . A line of cars evacuates the Homer Spit in Homer, Alaska on July 28, 2021, after a tsunami warning was issued following a magnitude 8.2 earthquake. The tsunami warning for much of Alaska's southern coast was canceled when the biggest wave, of just over a half foot, was recorded in Old Harbor. Alaska. The Associated Press Created: July 29, 2021 02:38 PM A powerful earthquake which struck just off Alaska's southern coast caused prolonged shaking and prompted tsunami warnings that sent people scrambling for shelters. Residents reported only minor damage, but officials said that could change after sunrise and people get a better look.