EMC125 TSUNAMI! How to Survive  1/3
To:   Emergency Communications Units - Information Bulletin
To:   Emergency Management Agencies via Internet and Radio
By:   Auxiliary Communications Service (ACS) of the
      California Governor's Office of Emergency Services  

EMC125  TSUNAMI! How to Survive. 1/3  For release 3/30/98

While the following is particularly applicable to West
Coast coastal areas, it is of interest of many people 
who want to know more about this tantalizing subject.

What follows is from a l996 publication of the California
OES Earthquake Program from the Earthquake Education
Center, Humboldt State University. Concept and some text
came originally from the Oregon Department of Geology
and Mineral Industries. Pamphlet is titled "TSUNAMI! 
How to Survive the Hazard on California's Coast"

Risk: Since l812 the California coast has had 14 tsunamis
with wave lengths higher than three feet; six of these
were destructive. The Channel Islands were hit by a big
tsunami in the early 1800s. The worst tsunami resulted
from the l964 Alaskan earthquake and caused 12 deaths and
at least $17 million in damages in northern California.

The l992 Cape Mendocino earthquake produced a one-foot 
tsunami that reached Humboldt Bay about 20 minutes after
the shaking. Although not damaging, this tsunami 
demonstrated that locally generated tsunamis can reach
the California coastline quickly. Had the earthquake
lasted longer, the wave heights would have been higher.
Evidence suggests that large earthquakes capable of
producing local tsunamis recur every two or three
hundred years.

What is a Tsunami (soo-nah'-mee)?
It is a series of sea waves most commonly caused by an
earthquake beneath the sea floor. In the open ocean the
waves travel at speeds up to 600 miles per hour. As the
waves enter shallow water, they rise rapidly. The waves
can kill and injure people and cause great property
damage when they come ashore. The first wave is often
not the largest; successive waves may be spaced many
minutes apart and continue arriving for a number of
hours.

Locally generated Tsunami
If a large earthquake displaces the sea floor near the
coast, the first waves may reach the shore minutes after
the ground stops shaking. There is no time for authorities
to issue a warning.

(Continues next week)
                                  ---
ACS Web page: http://acs.oes.ca.gov       FTP archive:
ftp.ucsd.edu/hamradio/packet/tcpip/incoming for new
bulletins and ftp.ucsd.edu/hamradio/races for earlier ones.
Landline BBS: 916-262-0856 (graphical & standard interface).
OES ACS staff manager Stan Harter :Stanly_Harter@oes.ca.gov 
State Chief ACS Officer Cary Mangum: Cary_Mangum@oes.ca.gov

EOM EMC125