California is one of the most scenic areas in all of the United
States, however this beauty comes at a price. The rugged terrain
found throughout the area is a result of active seismic activity.
One of the most active earthquake regions in the entire U.S. is
just off our coast, near Cape Mendocino. The numerous earthquakes
found here and around the entire Pacific Rim not only leads to frequent
shaking, but also the potential for tsunami or harbor waves. View
of tectonic plates and subduction zones in Northern California
Earthquakes are not a meteorological phenomena, but the Eureka NWS will
use its communication capabilities to disseminate information on earthquakes
felt in this area via NOAAWeather
Interesting Northwest California Earthquake
- California's North Coast, particularly in the vicinity of Cape Mendocino
is one of the most seismically active areasof the United States.
- About 25% of California's annual release of seismic energy comes
in this region.
- Since 1980, there have been five earthquakes close to magnitude 7.0.
- Since 1980, there have been six earthquakes of magnitude 6.0 or larger.
The United States Geological Survey, in Menlo Park
California, provides up to the minute Earthquake
Information. The latest reports are computer-generated messages and
are therefore preliminary until reviewed by a seismologist.
A Tsunami is a series of sea waves most commonly
caused by earthquakes beneath the sea floor. In the open ocean tsunami waves
travel at speeds up to 600 MPH. As these waves enter shallow waters they
may rise to several feet or in rare cases, tens of feet. It is in these
rare cases when life and property are in jeopardy as the large waves wash
The National Weather Service in Eureka is responsible for disseminating
Tsunami Watches/Warnings issued the Alaska
Tsunami Warning Center (ATWC) in
Palmer, Alaska. When a watch
or warning is issued, the message is immediately transmitted via
NOAAWeather Radio. There may also
be instances when a large earthquake materializes right offshore. This
could a produce a tsunami in such a rapid manner, that the AWTC would
not have time to issue a warning. Our office will then issue our own Tsunami
Statement and disseminate it via NOAA Weather Radio. If there is a tsunami
warning issued for a strong and long-lasting earthquake just off our shore
you should follow these rules.
- Protect yourself during the earthquake. Duck, cover and hold
if inside and watch for falling objects if outside until the earthquake
- Move to higher ground immediately. Gather your family members
and evacuate quickly. Leave everything else behind. A tsunami may be
coming in a matter of minutes. Go by foot if at all possible. If there
is no high ground, move inland and away from the coastline.
- Stay away from the coast. A later wave may be higher than
the first! Damaging waves may continue to arrive even hours later.
- Listen to NOAA Weather Radio, commercial radio or television.
Wait for some sort of "all clear" message before returning to low-lying