- Researchers have plotted movement of the tsunami from 1700 megaquake
- An event like is said to occur every 400-600 years, and is now overdue
- Cascadia Subduction Zone runs from Northern California- British Columbia
- Magnitude 9 shaking could last anything from three to five minutes
- Upward of 14,000 people would be left dead dead in worst-case scenarios, 30,000 injured
The threat of the ‘Big One’ has loomed over the Pacific Northwest for years.
A powerful earthquake thought to be as large as 9.2 magnitude ripped through the earth in 1700, along the 620 mile stretch of the Cascadia Subduction Zone, causing severe shaking and a massive tsunami.
Now, a terrifying new simulation from the Pacific Tsunami Warning Center has plotted the path of the tsunami as it traveled from the US to Japan.
Experts say an event of this kind occurs roughly every 400-600 years, and the area is now overdue for a similar quake that could leave thousands dead or displaced.
THE THREAT OF ‘THE BIG ONE’
Experts say an event of this kind occurs roughly every 400-600 years, and the area is now overdue for a similar quake that could leave thousands dead or displaced.
Worst-case scenarios show that more than 1,000 bridges in Oregon and Washington state could either collapse or be so damaged that they are unusable.
The main coastal highway, US Route 101, will suffer heavy damage from the shaking and from the tsunami.
READ-BREAKING: FIFTY! Earthquakes Shake Nevada in 24 hours! 21 of them “surface quakes” at zero depth!!!!
Traffic on Interstate 5 — one of the most important thoroughfares in the nation — will likely have to be rerouted because of large cracks in the pavement.
Seattle, Portland and other urban areas could suffer considerable damage, such as the collapse of structures built before codes were updated to take into account a mega-quake.
The historical tsunami struck the coasts of Japan just before midnight on January 27, 1700.
Scientists have finally traced the origins of this ‘orphan tsunami’ to a powerful seismic event in the Pacific Northwest of the United States, along the Cascadia Subduction Zone.
The researchers analysed sediment deposits and the ‘ghost forests’ of drowned trees, along with historical records from Japan and the oral histories of Native Americans, according to the PTWC.
Comparing the tree rings of dead trees with those still living allowed scientists to pinpoint the date of the last devastating earthquake.
The trees all died in the winter of 1699-1700, and the Pacific Northwest from Northern California to Washington suddenly sank up to 6 feet, flooding the area with seawater.
The animation from the Pacific Tsunami Warning Center, an effort by the National Oceanic and Atmospheric Administration and the National Weather Service, shows the real time path of the earthquake waves through the ocean, and what happens when the resulting tsunami waves hit land.
Researchers call this a RIFT model, Real-Time Forecasting of Tsunamis.
Using the earthquake information, the RIFT model shows movement, and predicts the speed, wavelength, and amplitude of the waves.
Wavelengths as well as height are indicated by colour.
The coastlines are all mapped with blue points at first, to represent normal sea level.
As the tsunami waves reach them, the points will change colour to indicate the height of the incoming waves.
Blue to green points indicate no hazard, yellow to orange indicates low hazard, light red to bright red means significant hazard which requires evacuation, with waves of up to 10 feet, and dark red indicates severe hazard, with waves reaching heights over 10 feet.
In the severe hazard zone, a second-tier evacuation may even be necessary.
Wavelengths as well as height are indicated by colour. The coastlines are all mapped with blue points at first, to represent normal sea level. As the tsunami waves reach them, the points will change colour to indicate the height of the incoming waves.
At the end of the animation, an ‘energy map,’ shows the beam of kinetic energy. Kinetic energy in the tsunami is highly directional, making it more severe in the middle than at the sides.
The coastlines in the path of the beam are also hit by larger waves than those to the side, PTWC explains.
This quieter cousin of the San Andreas Fault in California is far more dangerous, and could make itself known at any moment.
Running from Northern California to British Columbia, the Cascadia Subduction Zone can deliver a quake that’s many times stronger than San Andreas.
Seismologists say a full rupture of the more than 600-mile-long offshore fault and an ensuing tsunami is now only a matter of when.
Blue to green points indicate no hazard, yellow to orange indicates low hazard, light red to bright red means significant hazard which requires evacuation, with waves of up to 10 feet, and dark red indicates severe hazard, with waves reaching heights over 10 feet
The San Andreas Fault in California, has a quieter, far more dangerous cousin that could make itself known at any moment. Running from Northern California to British Columbia, the Cascadia subduction zone can deliver a quake that’s many times stronger than San Andreas ? and far more deadly
‘Cascadia can make an earthquake almost 30 times more energetic than the San Andreas to start with,’ Chris Goldfinger, a professor of geophysics at Oregon State University told CNN.
‘Then it generates a tsunami at the same time, which the side-by-side motion of the San Andreas can’t do’.
The Cascadia could deliver a huge 9.0-magnitude quake and the shaking could last anything from three to five minutes, scientists claim.
‘In this case, three minutes – and I’ve been in a 9 in Japan – three minutes is an eternity,’ said Goldfinger. ‘It is a very, very long time.’
Goldfinger says we’ll lose bridges, highway routes and that the coast will probably be entirely closed down.
As a result it would be difficult to get around, and rescue crews will be overwhelmed.
Federal, state and military officials have been working together to draft plans to be followed when the ‘Big One’ happens.
These contingency plans reflect deep anxiety about the potential gravity of the looming disaster: upward of 14,000 people dead in the worst-case scenarios, 30,000 injured, thousands left homeless and the region’s economy setback for years, if not decades.
As a response, what planners envision is a deployment of civilian and military personnel and equipment that would eclipse the response to any natural disaster that has occurred thus far in the US.
There would be waves of cargo planes, helicopters and ships, as well as tens of thousands of soldiers, emergency officials, mortuary teams, police officers, firefighters, engineers, medical personnel and other specialists.
‘The response will be orders of magnitude larger than Hurricane Katrina or Super Storm Sandy,’ said Lt. Col. Clayton Braun of the Washington State Army National Guard.
Oregon’s response plan is called the Cascadia Playbook, named after the threatening offshore fault — the Cascadia Subduction Zone.
The plan, unveiled last year, has been handed out to key officials so the state can respond quickly when disaster strikes.
WHAT WILL CAUSE KILLER QUAKE?
The Cascadia Subduction Zone (CSZ) ‘megathrust’ fault is a 1,000km-long line that stretches from Northern Vancouver Island to Cape Mendocino California.
It separates the Juan de Fuca, a 700-mile chunk in the Pacific Ocean, and North America plates.
For more than 300 years, the two plates have been pushing against one another.
Eventually, the Juan de Fuca will be pushed underneath the North America plate, causing the region to sink at least six feet.
The Cascadia Subduction Zone is where the North American tectonic plate meets another plate, the Juan de Fuca.
‘That playbook is never more than 100 feet from where I am,’ said Andrew Phelps, director of the Oregon Office of Emergency Management.
A magnitude 9.0 earthquake and tsunami that devastated parts of Japan in 2011 gave greater clarity to what the Pacific Northwest needs to do to improve its readiness for a similar catastrophe.
The Cascadia could deliver a huge 9.0-magnitude quake and the shaking could last anything from three to five minutes, causing widespread devastation. Pictured is the remains of the Cypress Freeway, which ran through the center of Oakland, following the San Francisco, or Loma Prieta, Earthquake of 1989
‘The Japanese quake and tsunami allowed light bulbs to go off for policymakers,’ Phelps said.
Much still needs to be done, and it is impossible to fully prepare for a catastrophe of this magnitude, but those responsible for drafting the evolving contingency plans believe they are making headway.
TRACKING THE CASCADIA
The Cascadia earthquake fault zone lies underwater between 40 and 80 miles offshore of the Pacific Northwest coastline.
Earthquake scientists have listening posts along the coast from Vancouver Island to Northern California, and have been using ships to drop off and later retrieve ocean bottom seismographs.
These record for up to a year right on top of the fault zone.
However, they have detected few signs of the grinding and slipping they expected.
The Cascadia Initiative (CI) is an onshore/offshore seismic and geodetic experiment that takes advantage of an Amphibious Array to study questions ranging from megathrust earthquakes to volcanic arc structure to the formation, deformation and hydration of the Juan De Fuca and Gorda plates
It is ‘a puzzle,’ according to University of Oregon geophysics professor Doug Toomey.
Two teams have been examining the area.
A joint Japanese-Canadian team dropped instruments offshore of Vancouver Island, while Toomey’s team is in its fourth year of deployments.
Named the Cascadia Initiative, it is rotating among subduction zone segments offshore of Washington, Oregon and Northern California.
Worst-case scenarios show that more than 1,000 bridges in Oregon and Washington state could either collapse or be so damaged that they are unusable.
The main coastal highway, US Route 101, will suffer heavy damage from the shaking and from the tsunami.
Traffic on Interstate 5 — one of the most important thoroughfares in the nation — will likely have to be rerouted because of large cracks in the pavement.
Seattle, Portland and other urban areas could suffer considerable damage, such as the collapse of structures built before codes were updated to take into account a mega-quake.
The last full rip of the Cascadia Subduction Zone happened in January 1700.
The exact date and destructive power was determined from buried forests along the Pacific Northwest coast and an ‘orphan tsunami’ that washed ashore in Japan.
Geologists digging in coastal marshes and offshore canyon bottoms have also found evidence of earlier great earthquakes and tsunamis.
The inferred timeline of those events gives a recurrence interval between Cascadia megaquakes of roughly every 400 to 600 years, reports the Pacific Northwest Seismic Network.
ADVICE ON HOW TO SURVIVE A PACIFIC NORTHWEST EARTHQUAKE
This diagram show the areas where land will be most affected by the shocks, causing landslides or liquefaction
Last year, scientists outlined their alarmingly unhelpful tips on how to survive the earthquake that will hit the Pacific Northwest.
The killer quake along Cascadia, a fault line which runs from Cape Mendocino, California, to Vancouver Island, Canada, is 72 years overdue, according to peer-reviewed studies.
The ‘Big One’ will hit when Juan de Fuca, a 700-mile chunk of the Pacific Ocean, slides under Canada and America, causing the entire coastal region to sink at least six feet.
When – not if – it arrives, it is unlikely the people of coastal Oregon, Washington and California will be able to escape.
But if they want to try, there are a few tips they should keep in mind.
Run, don’t drive, to higher ground, says Kevin Cupples, the city planner for the town of Seaside, Oregon, in an interview with the New Yorker.
The force of the quake will cause liquefaction, when solid ground acts like liquid, across vast swathes of the porous region.
In the areas that aren’t ‘liquefied’, the highways will likely be crumpled by landslides, with 30,000 avalanches set to hit Seattle alone.
Citizens will have a 20-minute interval to climb to the highest altitude possible before the full force of the tsunami hits, scientists predict.
Their alert will be when dogs start barking.
The first sign the quake is coming will be a set of compressional waves, only audible by dogs. Then there will be the quake, then 20 minutes later, the tsunami.
Geographers estimate that many could survive just by walking – however, they need to be going at least 3.5mph.
If everyone ups their average speed from 2.5mph to 3.5mph, the death toll drops to 15,970. About 70 per cent of them would be in Washington, nearly 30 per cent in Oregon and only 4 per cent in California.
And there is no point being a hero. ‘When that tsunami is coming, you run,’ Jay Wilson, the chair of the Oregon Seismic Safety Policy Advisory Commission, tells the New Yorker.
‘You protect yourself, you don’t turn around, you don’t go back to save anybody. You run for your life.’
The only other safety measure is to relocate away from the Pacific north west.
3 Pioneer Survival Lessons you should probably learn.WATCH THE VIDEO NOW
Source:http://www.dailymail.co.uk
(943)
The post ARE YOU READY FOR THE REALLY “BIG ONE”?Terrifying simulation shows how the Pacific Northwest could be decimated by a megaquake caused by the Cascadia fault appeared first on News Prepper.