All Pacific Northwest Earthquakes Around the Cascadia Subduction Zone From 1979 to Now.
https://www.youtube.com/watch?v=HcXX9RzUA0A
One of the most ‘terrifying’ disasters in the offing is a Cascadia Subduction Zone earthquake in the Pacific Northwest.The 1700 Cascadia earthquake occurred along the Cascadia subduction zone on January 26 with an estimated moment magnitude of 8.7–9.2.
The megathrust earthquake involved the Juan de Fuca Plate that underlies the Pacific Ocean, from mid-Vancouver Island in British Columbia, Canada, south along the Pacific Northwest coast as far as northern California. The length of the fault rupture was about 1,000 kilometers (620 miles) with an average slip of 20 meters (66 ft).
FEMA has prompted the Cascadia Preparedness Team to draw up immediate plans in the event of a worst case disaster scenario along the 620 mile subduction zone that runs from British Columbia to Northern California.
The Weather Network identified in a July report four “terrifying disasters waiting to happen.”One was deadly, exploding lakes in Africa. These are rare events known as limnic eruption and happen when CO2 builds up over time from nearby volcanic activity. Another potentially catastrophic event would be the onset of giant space rocks hitting the Earth.
This would be a global catastrophe, because particles in the atmosphere would block up to 70 percent of sunlight for the first couple of years. Besides that, particles suspended in the stratosphere would warm, stripping the Earth of about 55 percent of its ozone layer.
Two of the potential catastrophes would take place in the U.S., including the eruption of the supervolcano that rests beneath Yellowstone National Park. The report said that if the volcano were to erupt, it would produce enough ash to bury nearby cities and dust those on the coasts. The good news is that the last time this happened was 70,000 years ago and the “repeat” time would be 700,000 years.
The other disaster potentially in the offing is the Cascadia Subduction Zone earthquake. This scenario involves a magnitude 9.0 or worse earthquake in the Pacific Northwest that would be felt all the way down to Northern California. The Pacific Coast would have perhaps an hour of warning before the tsunami hit. As a reference point to how bad this earthquake will be, the recent earthquake in Japan that registered magnitude 6.2 lasted 20 seconds. The Cascadia quake would shake the earth for three to six minutes.
https://www.youtube.com/watch?v=Im2kpgjTJiw
The devastation would be great: If it happened tomorrow, there would be perhaps more than 10,000 deaths and 30,000 injuries. Whole cultures of people could be wiped out and the recovery would take decades. The good news? There’s probably ample time to prepare, and that preparation has begun. A similar quake is thought to have occurred in or before January 1700.
Scientists estimate that a recurrence would be due in about 500 to 600 years. But they don’t know for sure. They also don’t know how much seismic slip occurred during that quake in 1700. Did the subduction zone save anything?
“Faults tend to be pretty good at this. They don’t always spend everything they have,” said Brian Atwater of the U.S. Geological Survey Earthquake Hazards Program. There may have been a lot of “breakage” during the last quake or there could be parts of the fault that didn’t break. That would be a way to get “better than 500 years’ worth of slip in 300 years,” Atwater said. Or maybe the earlier quake spent the “whole bank account” and the future event won’t amount to much.
“That’s part of the challenge of trying to present to a public audience scenarios for future earthquakes and their unknowns,” said Atwater. “They don’t happen like clockwork.”
Rebekah Paci-Green is the director of the Resilience Institute and a professor at Western Washington University. She helped put together Cascadia Rising, a 182-page document that goes into alarming detail about the impending Cascadia earthquake and tsunami.
The document takes you through the scenario of The Quake. The daytime quake will sneak up on the region’s population, feeling somewhat like a semi-truck passing by. As the shaking continues, some will forget their initial training. Some may run, but will make it only a few steps before falling. After about a minute, the shaking will begin to toss people about. Things not anchored will fall. Some people will have gotten under chairs, tables or something they think will protect them. Many will not.
The document says that coastal areas will likely feel it the worst. But down in Oregon and even Northern California, residents will know something is afoot.
Also Read: REVEALED:US PREPARES FOR BIG ONE MAG 9.0 EARTHQUAKE THAT WILL HIT FIVE TIMES SPEED OF SOUND
The Damage
Besides the dead and injured, the damage to infrastructure would be enormous. One of the big threats during such a quake is liquefaction. Many critical structures stand on silt and sand that become unstable. The grainy soil will begin to act like liquid, and structures — such as bridges, ports, airports and industrial facilities — may shift position or sink.
Local residents will have 20 to 30 minutes to get to high ground and away from the effects of the inevitable tsunami, which will consist of multiple waves over several hours. Some areas will remain flooded even as the tsunami retreats.
There are complete cultures in Washington that could be completely wiped out. “It’s a catastrophic event that will affect a wide swath of our state and Oregon, British Columbia and Northern California,” said Paci-Green. “It is absolutely catastrophic for outer-coast communities, and beyond catastrophic for some of the tribes where a large percentage of their reservation is in the inundation zone.”
https://www.youtube.com/watch?v=CLZs9LirF0k