News

Tsunami warning for Bay Area after 8.9 quake in Japan

March 11, 2011 5:06 am by Lance Knobel

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:

11 Comments

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  • http://www.yourmomissoberkeley.com Berto

    So it’s really hard to figure out what this means for Berkeley. Words like “coastal” that come up in a lot of the stories I’m finding aren’t helpful. I’m hearing 9 foot waves on the west coast. What does that mean for us on say, San Pablo Ave? Please, if you can find this info, help us out. So far I’ve found nothing that really helps e get a sense of what I should be expecting.

  • http://www.berkeleyside.com Lance Knobel

    Berto, I’m having the same problems you are. The NWS map clearly shows a warning for Berkeley and Oakland, in addition to more obvious locations on the Pacific coast. One of the problems with the timing of this is there are no expert sources to reach right now.

    Not sure where you are hearing 9 foot waves. The NWS forecast clearly expects 1- or 2-foot waves. Here’s the forecast: http://www.wrh.noaa.gov/warnings.php?wfo=mtr&pil=XXXSPSMTR&zone=caz006&productType=Special%20Weather%20Statement.

    I think the prudent advice would be to avoid areas near the Bay just after 8 a.m.

  • http://twitter.com/Weezus Rachel A.

    Thanks for this post and the links, Lance & Berkeleyside. As a Rosa Parks Elementary parent I was curious about the possible impact and am glad to see it seems unlikely. (It helps that our school starts at 9 a.m.) I was grateful to have a local resource to check.

  • Aditya

    I found this inundation map for various parts of Alameda county (warning: large PDF maps are slow to load) that has detailed predictions (not tied to this particular tsunami) for possible inundation of the coastal areas. These are extreme predictions but should be a good upper bound at least (in the sense that if you’re east of the red lines, it’s probably very low risk).
    http://www.conservation.ca.gov/cgs/geologic_hazards/Tsunami/Inundation_Maps/Alameda/Pages/Alameda.aspx#find%20out%20more

    For example, in Berkeley, nothing east of 4th street is at risk according to the map. The individual maps (available at links on the main page linked above) are zoomed in areas of the marked squares on the main map.

  • Sharkey

    Oof, I hope they don’t shut down BART!

    Better safe than sorry, I suppose.

  • http://Berkeleyhomes.com/blog Ira Serkes

    I80 or Amtrak/UP/BNSF Rail Traffic shut down?

  • Diane

    Does anyone know how far San Pablo is from Crescent city? Is that area in danger?

  • Jesse Townley

    Crescent City is at the border of California & Oregon.

  • Melanie

    @Jesse Townley says:
    “Crescent City is at the border of California & Oregon.”

    Eek! Skimmed that too quickly, and wondered for a second if we were expecting surges around the corner of California and Oregon Streets. I’ve clearly lived here too long.

    Says Bay Citizen at 9:15 a.m.:

    http://www.baycitizen.org/weather/story/bay-area-sees-surges-some-impact-japans/

    (My poor daughter called me from England about 5:30 this morning, sobbing, “Are you OK? Haven’t you heard?” The first Internet reports had convinced her that giant waves were about to bear down on her hometown.)

  • KMG

    Thanks, Berkeleyside, and readers, for providing useful links. I figured I could come here and get my question of, “is my area in danger?” answered quickly. Not that we shouldn’t be alert regardless, but it helps to see the map.

  • Steven Winter

    The tsunami (small as it was) did make it to Emeryville. I grabbed a snapshot of it:
    http://www.flickr.com/photos/51276066@N00/5517993750/