Tsunami warning for Bay Area after 8.9 quake in Japan

Orange areas on the map are subject to tsunami warning

The National Weather Service has issued a tsunami warning for Northern California, following last night’s magnitude 8.9 quake off the coast of Japan. The warning estimates wave heights of 2 feet for Fort Point. The tsunami is expected to reach the Bay Area at just after 8 a.m. this morning. Numerous roads in the Bay Area are being closed by the California Highway Patrol in anticipation of the tsunami.

Although those wave heights may not sound very large, the energy behind a tsunami wave can be far greater than much higher conventional waves. People in tsunami areas should move inland and to higher elevations. The National Weather Service provides advice on tsunamis on its site.

Lori Dengler, a geologist at Humboldt State University, told CNN this morning that the expected tsunami has the potential to be as damaging as the one that hit the West Coast in 1964. Japan’s quake is the fifth largest recorded by the United States Geological Survey since 1900.

This map of predicted wave amplitude following the quake gives a graphic image of the forces unleashed by the quake:

The New York Times is doing an updated blog on the earthquake and the resulting tsunami.

Update 5:36 BART has issued a notice that it is monitoring the situation. At the moment, there are no interruptions planned, but it may decide to stop transbay services as more information emerges.

Update 6:19 Berkeleysider @jmccyoung tweets that inundation maps show very little danger to Berkeley east of railroad tracks. That still puts Cesar Chavez Park, Aquatic Park and I-80 in potential danger areas. You can find the inundation maps here, but I was unable to get the detail to load.

Update 7:18 We were finally was able to load that inundation map, created for emergency planning by the California Emergency Management Agency. Note: this is a general map for the expected consequences of tsunami flooding. It doesn’t predict what may happen in any individual instance. Here is the Berkeley detail: