The Cascadia Subduction Zone

Automatic TRANSCRIPT

Today we're going to look at the Cascadia subduction zone, and what could be a mega quake the Pacific northwest subduction zone earthquakes have occurred every three hundred fifty years since six hundred BC with the most recent taking place January twenty six seventeen o one evidence for earlier quakes come from core samples taken from the. The Ocean floor, and from rings counted in the Ghost forest that I'll talk about a little bit later. The seventeen hundred quake caused several coastal regions, Washington and Oregon to drop sixty six feet, massive coastal storms during nine, hundred and ninety, seven, Ninety, eight, washed away tons and tons of sand, revealing hundreds of stumps, the remnants of a Sitka spruce forced. It is through. Through a combination of carbon dating an accounting of rings that the data, the last Cascadia subduction zone or C. S. Z. quake took place. The Earth's surface is made up of seven major plates and many smaller ones. The smaller plates creator earthquakes for short durations of fourteen forty five seconds at may reach nine point five on the Richter scale. They often take place of. Of Water call faultlines between plates March Eleventh Twenty Eleven Japan experience a subduction zone. Quite that lasted more than four minutes at nine point one on the Richter scale. It was a fourth, most powerful or quake in the world. Since modern recording began in nineteen, hundred shake created a Su- Nami, the reached a hundred and thirty three feet and mood six miles inland google. Google Japan's main island upon shoot, eight feet in shifted the earth on its axis between four and ten inches, this was an earthquake created by the shifting of the Pacific Plate finally to help put earthquakes in perspective, the long Prieta quake that interrupted the nineteen eighty nine world series in San Francisco. California lasted fifteen seconds the Great San Francisco earthquake of nineteen six was. was eight point six that lasted forty five seconds, but Japan's greater earthquake of twenty eleven lasted over four minutes at nine point, one of the Richter scale based on data from Oregon see geographer Patrick Corcoran and Usgs Alaska, science center kiss, missing mysteries will now tour the predicted minute by minute impact of Cascadia. Subduction Zone earthquake on the Oregon coast after three hundred twelve. Twelve years to see S Z could no longer take the strain it ruptures at a spot fifty five miles west of Cannon Beach Oregon and quickly spreads along the seven hundred miles of its length from British Columbia to Mendocino California. The North American plate slips fifty seven feet to the south. West sliding over the Wanda Fuca plate, but remember we're talking about across more. More than fifty miles deep, the first movement sons pressure wave that soapy way that travels through the Earth's crust at thirteen thousand miles an hour, it will reach the West Coast in ten seconds. The leading edge will hit Oregon's cannon beach and seaside thirty seconds later. It reaches Portland in fifty seconds his Seattle at nine point one is what seismologist call a full rip? Most cities can withstand a six point. Eight quake lasted about forty five seconds, but the difference between a forty second, and a four-minute quake has like the difference between a head on collision at four miles, an hour and forty miles an hour within three minutes shaking continues, the coast will drop from six to twenty five feet after five minutes. The worst is over for Portland and Seattle it will have suffered from ground liquefication Berlin will collapse, and they'll be gas fires citywide after six. Six minutes people seeking high ground to avoid the soon. NAMI will be impeded by debris driving. We'll be an impossibility at eight minutes. Nami will be about twenty five miles offshore. It approaches like an enormous high tide, but a flash flood speed leading edge will only be inches, but will increase to forty feet as predicted that the cascadia subduction zone quake would create twice the impact of Japan's great quake twenty eleven. Keep in mind the by the time you finish listening to this. There will have been earthquakes somewhere in the world. The Pacific

Coming up next