Thanks to Sumatra
our appreciation of the risk level has seriously jumped. That makes the exposed coastline extremely
vulnerable and should become no build zones.
Fortunately, along Vancouver Island, that has proven largely impossible
and particularly unpleasant anyway.
Better the urban
heartland is situated in the lee of the actual coastal ridge which acts as a
huge damper in the event of a mega quake.
There are still gaps in the defenses, particularly through the Juan de Fuca
strait where bad luck can lead to an awful day.
In reality our
West Coast is far less vulnerable that the Japanese coastline, simply because
we have less targets to actually hit.
The worst area of vulnerability is in river mouths and the odd coastal
plain. Off course it is going to take a
tsunami to change the building codes there.
Earthquakes on
the Pacific Northwest.
West Coast Earthquakes Mitch Battros writes, “It
seems as though the 6.9 magnitude earthquake on March 10, 2014, just off the
coast of northern California was just a whimper so people are not to be overly
concerned. But you won’t find a single seismologist who would agree with such a
notion. In fact, it would appear every seismologist, geologist, and
volcanologist is on high alert knowing the potential danger hovering like a
mist over the entire west.”
Within minutes of the northern California 6.9 event,
modern 3.0 to 4.0 quakes popped up just north of Washington State on the border
with Canada. Within this same period, a volcano in Alaska lit-up. On March 11,
2014, a 5.1 mag. quake hit just off the coast of Oregon. Put these events
together and you just outlined the Cascadia Subduction Zone; one of the most
volatile and dangerous zones along the entire North American continent.
This is not a time to panic, but you would be
foolish not to be reasonably prepared. The Pacific Northwest has a 40% chance
of being hit by a magnitude 8 or larger earthquake in the next 1 to 50 years.
That’s more than double previous estimates of a 10-15% risk.
Great Subduction Zone earthquakes are the largest
earthquakes in the world, and can exceed magnitude 9.0. Earthquake size is
proportional to fault area, and the Cascadia Subduction Zone is a very long
sloping fault that stretches from mid-Vancouver Island to Northern California.
It separates the Juan de Fuca and North American plates. Because of the
very large fault area, the Cascadia Subduction Zone could produce a very large
earthquake. Thermal and deformation studies indicate that the locked zone is
fully locked for 60 kilometers (about 40 miles) downdip from the deformation
front.
Further downdip, there is a transition from fully
locked to aseismic sliding. Over the past 10,000 years, there have
been 19 earthquakes that extended along most of the margin, stretching from
southern Vancouver Island to the Oregon-California border. These would
typically be of a magnitude from about 8.7 to 9.2 – really huge earthquakes. Researchers have also determined that
there have been 22 additional earthquakes that involved just the southern
end of the fault. The last mega-earthquake to strike the Pacific Northwest
occurred on Jan. 26, 1700. Written records in Japan document how an ensuing
tsunami destroyed that year’s rice crop stored in warehouses.
The clock is ticking on when a major earthquake will
next strike, Jay Patton, an OSU doctoral student and a co-author on the study
When it hits: Violent shaking may last two minutes
or more. The ocean floor will drop, most likely creating a tsunami that will
strike long stretches of the coast. The central Olympic peninsula will suddenly
rise, while some continue to arrive for hours. - coastal areas will sink below
sea level.
If an earthquake occurs at or near coastlines:
- Drop, cover and hold. Get under a sturdy object and hold on. Watch for
falling objects. - As soon as the shaking is over, move to high ground or
inland. Do not wait for an official warning. - Stay away from the coastal
waters. Waves may
Listen to your local radio station for an official
“All Clear” notice before returning to the coastal area. - Be alert for
aftershocks. Protect yourself and your family: - Develop a family
disaster plan. Everyone needs to know what to do on their own to protect
themselves from an earthquake. - Be familiar with local Emergency Management
earthquake and tsunami plans. Know where to go to survive a tsunami. - Be
prepared to survive on your own for a minimum of three days. - Prepare a
disaster supply kit for your home, automobile and work. Take a first aid course
and learn survival skills. Knowledge is your greatest defense against potential
disaster.
ECM survival
guide: http://earthchangesmedia.com/survival_guide March 2014 Thanks to
Mitch Battros
1 comment:
All studies of the Cascadia fault indicate shaking on, or about every two hundred years. If the trend continues, "we are overdue" for some major movement along this fault line.
Everyone... and I do mean everyone should have drinking water, food, and seasonal clothing stored in their vehicles, home, and work.
Do Not depend on others to save or rescue you in times of disaster. You must be alert to conditions surrounding you at all time. Where you can, carry sufficient supplies that you can help others when necessary. Expect that "most" people will not be ready for the shake.
Those in low lying coastal areas need to know "where the high ground is." DO NOT go searching on the beach when the tide goes out... folks, it will come back in, and you can't run that fast.
Good luck, just 'cause you are inland does not mean you are totally safe... BE PREPARED.
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