U.S. MEGA-EARTHQUAKE & TSUNAMI, PACIFIC NORTHWEST RING OF FIRE

The Pacific Northwest is 69 years past due for a continent-rending earthquake which will generate a very high tsunami wave as other major quakes there have done in the past.

Scientists estimate the odds of a "Big One" happening in the next 50 years are about one in three, the odds of a "Very Big One" roughly one in ten, but say we are disastrously unprepared for such a seismic event.

ABOVE, THE RED LINE REPRESENTS THE SEISMICALLY AND VOLCANICALLY ACTIVE "RING OF FIRE" AREAS ON BOTH SIDES OF THE PACIFIC OCEAN, WITH THE RED ARROWS INDICATING THE DIRECTION IN WHICH THE PACIFIC TECTONIC PLATE IS SLIDING.

"On the periphery of the Pacific Ocean, the edge of the Pacific Continental Plate is expanding in the seabed, and is hitting the North American Plate, the Nazca Plate, the Eurasian Plate, and other plates, causing the margins of the plates to collide, buckle, and compress, causing earthquakes and volcanoes."

"Most of the active volcanoes on Earth are located on this circumference." 

[FOR A HISTORY OF EARTHQUAKES IN THIS REGION, SEE http://www.crew.org/earthquake-information/history-of-earthquakes-in-cascadia]

ABOVE, A LOOK AT SEISMIC ACTIVITY ALONG THE PERIPHERY
OF THE RING OF FIRE.
(Yellow circles represent earthquakes deeper than 35 kilometers.)


41 BIG QUAKES (Magnitude 8 or more) IN THE PAST 10,000 YEARS, ONE EVERY 247 YEARS...AND THE LAST MEGA-QUAKE WAS IN 1700, THREE HUNDRED AND SIXTEEN YEARS AGO...316 YEARS , MAKING THE NEXT ONE 69 YEARS PAST DUE.

THAT 1700 QUAKE WAS ESTIMATED TO BE A MAGNITUDE 9.
A magnitude 7.5 event occurred around 900 A.D. along the Seattle Fault.
The more recent Klamath Falls 'twin' quakes (Both registered magnitude 6.0, 1993) and Nisqually quake (Magnitude 6.8, 2001) served as reminders that, like California, both Oregon and Washington are very seismically active and large quakes do happen.

SEISMOLOGISTS AND OTHER SCIENTISTS SAY THAT THE CASCADIA SUBDUCTION ZONE IS QUITE CAPABLE OF PRODUCING ANOTHER 9.0 MAGNITUDE QUAKE, AND SAY IT CAN HAPPEN, LITERALLY, AT ANY MOMENT NOW.

ABOVE, SUBDUCTION EXPLAINED.

THE CASCADIA SUBDUCTION ZONE OF AMERICA'S WEST COAST IS ONE OF THE DEADLIEST ON EARTH.

The Cascadia subduction zone is far worse than the San Andreas fault .

According to CNN, "the largest earthquake in the continental United States" took place along the Cascadia Subduction Zone on January 26th, 1700.

The Cascadia Subduction Zone is where the Juan de Fuca plate meets the North American plate.
It stretches approximately 700 miles from northern Vancouver Island, Canada, all the way down to northern California. 

If the entire zone gives way at once, an event that seismologists call a full-margin rupture, the magnitude of the earthquake will be somewhere between 8.7 and 9.2.

ABOVE, RED LINE SHOWS INTERSTATE 5, PACIFIC NORTHWEST...

Kenneth Murphy, who directs FEMA's Region X, the division responsible for Oregon, Washington, Idaho, and Alaska, says, "Our operating assumption is that everything west of Interstate 5 will be toast."

In the Pacific Northwest, everything west of Interstate 5 covers some one hundred and forty thousand square miles, including Seattle, Olympia and Tacoma in Washington state, Portland, Eugene and Salem in Oregon, and about seven million people.

"By the time the shaking has ceased and the tsunami has receded, the region will be unrecognizable." 

 

OSSPAC estimates that in the I-5 corridor it will take between one and three months after the earthquake to restore electricity, a month to a year to restore drinking water and sewer service, six months to a year to restore major highways, and eighteen months to restore health-care facilities. 

On the coast, those numbers go up. 
Whoever chooses to or has no choice but to stay there will spend three to six months without electricity, one to three years without drinking water and sewage systems, and three or more years without hospitals. 

Those estimates do not apply to the tsunami-inundation zone, which will remain all but uninhabitable for years.

ABOVE, THE BLUE-SHADED AREA IS THE CASCADE MOUNTAINS CHAIN, PACIFIC NORTHWEST, A LINE OF ANCIENT VOLCANOES, SOME OF WHICH HAVE BECOME HIGHLY ACTIVE IN THE PAST FEW DECADES.

13 MAJOR VOLCANIC CENTERS

This region is one of the youngest and most tectonically active in North America.

The Cascades are made up of a band of thousands of small, short-lived volcanoes that have built a platform of lava and volcanic debris. Rising above this volcanic platform are a few strikingly large volcanoes that dominate the landscape. 

The Cascades volcanoes define the Pacific Northwest section of the Ring of Fire.
 
Within this region, 13 major volcanic centers lie in sequence, like a string of explosive pearls.


WHAT TO EXPECT

[PLEASE, SHARE THIS WITH ANYONE, EVERYONE YOU KNOW WHO LIVES IN THIS REGION. SHARE THE ORIGINAL ARTICLES, NOT THE TEA ROOM'S TAKE ON IT. LET THE SCIENCE SPEAK FOR ITSELF SO PEOPLE WILL PAY ATTENTION TO THE WARNINGS.]

"The first sign that the Cascadia earthquake has begun will be a compressional wave, radiating outward from the fault line. 

Compressional waves are fast-moving, high-frequency waves, audible to dogs and certain other animals but experienced by humans only as a sudden jolt. 
They are not very harmful, but they are potentially very useful, since they travel fast enough to be detected by sensors thirty to ninety seconds ahead of other seismic waves. 

That is enough time for earthquake early-warning systems, such as those in use throughout Japan, to automatically perform a variety of lifesaving functions: shutting down railways and power plants, opening elevators and firehouse doors, alerting hospitals to halt surgeries, and triggering alarms so that the general public can take cover. 

The Pacific Northwest has no early-warning system. 

When the Cascadia earthquake begins, there will be, instead, a cacophony of barking dogs and a long, suspended, what-was-that moment before the surface waves arrive. 

Surface waves are slower, lower-frequency waves that move the ground both up and down and side to side: the shaking, starting in earnest. 

Soon after that shaking begins, the electrical grid will fail, likely everywhere west of the Cascades and possibly well beyond. 

If it happens at night, the ensuing catastrophe will unfold in darkness. 

In theory, those who are at home when it hits should be safest; it is easy and relatively inexpensive to seismically safeguard a private dwelling. 

But, lulled into nonchalance by their seemingly benign environment, most people in the Pacific Northwest have not done so. 

That nonchalance will shatter instantly. 

So will everything made of glass.

Anything indoors and unsecured will lurch across the floor or come crashing down: bookshelves, lamps, computers, canisters of flour in the pantry. 

Refrigerators will walk out of kitchens, unplugging themselves and toppling over. 

Water heaters will fall and smash interior gas lines. 

Houses that are not bolted to their foundations will slide off—or, rather, they will stay put, obeying inertia, while the foundations, together with the rest of the Northwest, jolt westward. Unmoored on the undulating ground, the homes will begin to collapse.

Across the region, other, larger structures will also start to fail. 

BUILDINGS/HOMES BUILT BEFORE 1974 AND UP TO 1994 ARE MOST AT RISK, 75% OF ALL STRUCTURES IN OREGON. 

 

Until 1974, the state of Oregon had no seismic code, and few places in the Pacific Northwest had one appropriate to a magnitude-9.0 earthquake until 1994. 

The vast majority of buildings in the region were constructed before then. 

Ian Madin, who directs the Oregon Department of Geology and Mineral Industries (DOGAMI), estimates that seventy-five per cent of all structures in the state are not designed to withstand a major Cascadia quake.  

FEMA calculates that, across the region, something on the order of a million buildings—more than three thousand of them schools—will collapse or be compromised in the earthquake. 

So will half of all highway bridges, fifteen of the seventeen bridges spanning Portland’s two rivers, and two-thirds of railways and airports; also, one-third of all fire stations, half of all police stations, and two-thirds of all hospitals.

The shaking from the Cascadia quake will set off landslides throughout the region—up to thirty thousand of them in Seattle alone, the city’s emergency-management office estimates. 

It will also induce a process called liquefaction, whereby seemingly solid ground starts behaving like a liquid, to the detriment of anything on top of it. 

Fifteen per cent of Seattle is built on liquefiable land, including seventeen day-care centers and the homes of some thirty-four thousand five hundred people. 

So is Oregon’s critical energy-infrastructure hub, a six-mile stretch of Portland through which flows ninety per cent of the state’s liquid fuel and which houses everything from electrical substations to natural-gas terminals. 

 Together, the sloshing, sliding, and shaking will trigger fires, flooding, pipe failures, dam breaches, and hazardous-material spills. 

Any one of these second-order disasters could swamp the original earthquake in terms of cost, damage, or casualties—and one of them definitely will. 

Four to six minutes after the dogs start barking, the shaking will subside. 
For another few minutes, the region, upended, will continue to fall apart on its own. 

Then the wave will arrive, and the real destruction will begin. 

Among natural disasters, tsunamis may be the closest to being completely unsurvivable.  

The only likely way to outlive one is not to be there when it happens: to steer clear of the vulnerable area in the first place, or get yourself to high ground as fast as possible.

 For the seventy-one thousand people who live in Cascadia’s inundation zone, that will mean evacuating in the narrow window after one disaster ends and before another begins. 

They will be notified to do so ONLY by the earthquake itself—“a vibrate-alert system,” Kevin Cupples, the city planner for the town of Seaside, Oregon, jokes—and they are urged to leave on foot, since the earthquake will render roads impassable. 

Depending on location, they will have between ten and thirty minutes to get out. 

That time line does not allow for finding a flashlight, tending to an earthquake injury, hesitating amid the ruins of a home, searching for loved ones, or being a Good Samaritan. 

“When that tsunami is coming, you run,” Jay Wilson, the chair of the Oregon Seismic Safety Policy Advisory Commission (OSSPAC), says. “You protect yourself, you don’t turn around, you don’t go back to save anybody. You run for your life.”

"WE CAN'T SAVE THEM."

Lax safety policies guarantee that many people inside the inundation zone will not get out. 

 Twenty-two per cent of Oregon’s coastal population is sixty-five or older. 
Twenty-nine per cent of the state’s population is disabled, and that figure rises in many coastal counties.

 “We can’t save them,” Kevin Cupples says. “I’m not going to sugarcoat it and say, ‘Oh, yeah, we’ll go around and check on the elderly.’ No. We won’t.” 

Nor will anyone save the tourists. 
Washington State Park properties within the inundation zone see an average of seventeen thousand and twenty-nine guests a day. 

Ian Madin, who directs the Oregon Department of Geology and Mineral Industries (DOGAMI) estimates that up to a hundred and fifty thousand people visit Oregon’s beaches on summer weekends.
 “Most of them won’t have a clue as to how to evacuate,” he says. “And the beaches are the hardest place to evacuate from.” 

Those who cannot get out of the inundation zone under their own power will quickly be overtaken by a greater one. 

A grown man is knocked over by ankle-deep water moving at 6.7 miles an hour. 

The tsunami will be moving more than twice that fast when it arrives.

 20- TO 100-FEET TSUNAMI WAVE

Its height will vary with the contours of the coast, from twenty feet to more than a hundred feet. 

 It will not look like a Hokusai-style wave, rising up from the surface of the sea and breaking from above. 
It will look like the whole ocean, elevated, overtaking land.
Nor will it be made only of water—not once it reaches the shore.
It will be a five-story deluge of pickup trucks and doorframes and cinder blocks and fishing boats and utility poles and everything else that once constituted the coastal towns of the Pacific Northwest.

To see the full scale of the devastation when that tsunami recedes, you would need to be in the international space station.
The inundation zone will be scoured of structures from California to Canada.

The earthquake will have wrought its worst havoc west of the Cascades but caused damage as far away as Sacramento, California—as distant from the worst-hit areas as Fort Wayne, Indiana, is from New York.  

FEMA expects to coördinate search-and-rescue operations across a hundred thousand square miles and in the waters off four hundred and fifty-three miles of coastline. 

As for casualties: the figures I cited earlier—twenty-seven thousand injured, almost thirteen thousand dead—are based on the agency’s official planning scenario, which has the earthquake striking at 9:41 A.M. on February 6th. 

If, instead, it strikes in the summer, when the beaches are full, those numbers could be off by a horrifying margin.

COMPLETELY UNPREPARED

The Cascadia subduction zone remained hidden from us for so long because we could not see deep enough into the past.
 It poses a danger to us today because we have not thought deeply enough about the future.
That is no longer a problem of information; we now understand very well what the Cascadia fault line WILL someday do.


IT HAS HAPPENED BEFORE.


How should a society respond to a looming crisis of uncertain timing but of catastrophic proportions?
How can it begin to right itself when its entire infrastructure and culture developed in a way that leaves it profoundly vulnerable to natural disaster?

At an elementary school in the community of Gearhart, the children will be trapped. 

“They can’t make it out from that school,”Doug Dougherty, the superintendent of schools for Seaside, which lies almost entirely within the tsunami-inundation zone, said.
“They have no place to go.”

On one side lies the ocean; on the other, a wide, roadless bog.
When the tsunami comes, the only place to go in Gearhart is a small ridge just behind the school.
At its tallest, it is forty-five feet high—lower than the expected wave in a full-margin earthquake.
For now, the route to the ridge is marked by signs that say “Temporary Tsunami Assembly Area.” I asked Dougherty about the state’s long-range plan.

“There is no long-range plan,” he said.

Dougherty’s office is deep inside the inundation zone, a few blocks from the beach.
All day long, just out of sight, the ocean rises up and collapses, spilling foamy overlapping ovals onto the shore.

Eighty miles farther out, ten thousand feet below the surface of the sea, the hand of a geological clock is somewhere in its slow sweep.

All across the region, seismologists are looking at their watches, wondering how long we have, and what we will do, before geological time catches up to our own. "

... 
JANUARY 12, 2016
"SLOW" EARTHQUAKE ALONG CASCADIA SUBDUCTION ZONE
from SCIENTIFIC AMERICAN
"We're used to thinking of earthquakes as events that happen over seconds to a few minutes and produce a lot of shaking, but some earthquakes actually mosey along over hours or days, the trembling so gentle only seismometers can recognize it.

One of these earthquakes started in the Cascadia Subduction Zone on December 21st and has been making its slow way south from Vancouver Island, British Columbia, Canada ever since. "

"Every 12-15 months these slow earthquakes occur in the Cascadia Subduction Zone beneath southern Vancouver Island and northern Washington.

One of these events is happening right now and is possibly connected to the magnitude 4.8 earthquake NE of Victoria, Canada that occurred on December 29.

I like to call slow earthquakes the banana slugs of earthquakes.  This is because while slow earthquakes can release the same amount of energy as a magnitude 6.5-6.8 normal earthquake, they release this energy more slowly. 

 For example, many of you who have been living in the Pacific Northwest for a long time probably remember the magnitude 6.8 Nisqually earthquake in 2001. 

The shaking during this earthquake lasted about 15 seconds.  A slow earthquake of the same magnitude lasts for weeks; the magnitude 6.8 slow earthquake in 2010 lasted from August 8 to September 8.

The current slow earthquake began on December 21 beneath Vancouver Island, Canada.  Activity continued beneath Vancouver Island for 8 days and now the slow earthquake is migrating southward beneath the Straight of Juan de Fuca.

Slow earthquakes happen almost every year and are thought to be part of the normal cycle of energy release in the subduction zone. "

13-year Cascadia study complete – and earthquake risk looms large

08/01/2012

CORVALLIS, Ore. – A comprehensive analysis of the Cascadia Subduction Zone off the Pacific Northwest coast confirms that the region has had numerous earthquakes over the past 10,000 years, and suggests that the southern Oregon coast may be most vulnerable based on recurrence frequency.

Written by researchers at Oregon State University, and published online by the U.S. Geological Survey, the study concludes that there is a 40 percent chance of a major earthquake in the Coos Bay, Ore., region during the next 50 years. And that earthquake could approach the intensity of the Tohoku quake that devastated Japan in March of 2011.

“The southern margin of Cascadia has a much higher recurrence level for major earthquakes than the northern end and, frankly, it is overdue for a rupture,” said Chris Goldfinger, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences and lead author of the study. 

“That doesn’t mean that an earthquake couldn’t strike first along the northern half, from Newport, Ore., to Vancouver Island.
“But major earthquakes tend to strike more frequently along the southern end – every 240 years or so – and it has been longer than that since it last happened,” Goldfinger added. 

“The probability for an earthquake on the southern part of the fault is more than double that of the northern end.”

PLEASE, DO NOT TAKE THIS LIGHTLY.
THE RESIDENTS OF THE CASCADIA AREA HAVE NOT BEEN PROPERLY PREPARED FOR THIS.
WITH THE ABOVE KNOWLEDGE, ALL CAN BE MORE PREPARED, SO DO PASS THIS ON TO ANY YOU KNOW WHO COULD USE SUCH KNOWLEDGE.






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FURTHER READING, IMPORTANT DATA

~ This scenario characterizes the effects of a major subduction earthquake on communities along the Cascadia Subduction Zone, stretching from the Brooks Peninsula on Vancouver Island to Cape Mendocino in northern California.
Download the scenario here.


~ WHAT ARE THE GEOLOGIC HAZARDS IN OREGON?
Earthquakes. Cascadia Subduction Zone. Crustal. Deep Intraplate. Volcanic. Tsunami.
A PDF file viewable online.


~ THE NEW YORKER MAGAZINE
http://www.newyorker.com/magazine/2015/07/20/the-really-big-one


~ History of West Coast Earthquakes
http://www.crew.org/earthquake-information/history-of-earthquakes-in-cascadia
http://www.crew.org/earthquake-information
 
~ Earthquake hazards - Oregon at Risk