During an eruption, if the wind is from the east at 10,000 feet (outflow), the tephra will fall on Vancouver, Canada in about an hour. This Page Hyperlinked [click on] Mount Baker Stratovolcano (background)© ™ ®/ Kulshan Stratovolcano© ™ ®, Simon Fraser University (foreground)© ™ ® ~ Image by Stan G. Webb - In Retirement© ™ ®, An Intelligent Grandfather's Guides© ™ ® next, The Man From Minto© ™ ® - A Prospector Who Knows His Rocks And Stuff© ™ ®
Learn more about the Cascadia Volcanic Arc© ™ ® (Part of Pacific Ring of Fire) Cascadia Volcanoes© ™ ® and the currently active Mount Meager Massif© ™ ®, part of the Cascadia Volcanic Arc© ™ ® [ash flow, debris flows, fumaroles and hot springs], just northwest of Pemberton and Whistler, Canada ~ My personal interest in the Mount Meager Massif© is that the last volcanic vent blew north, into the Bridge River Valley [The Bridge River Valley Community Association (BRVCA), [formerly Bridge River Valley Economic Development Society], near my hometown. I am the Man From Minto© ™ ® - A Prospector Who Knows His Rocks And Stuff© ™ ® The 2010 Mount Meager landslide was a large catastrophic debris avalanche that flowed to the south, into the Lillooet Valley British Columbia, Canada, on August 6 at 3:27 a.m. PDT (UTC-7). More than 45,000,000 m3 (1.6×109 cu ft) of debris slid down Mount Meager, temporarily blocking Meager Creek and destroying local bridges, roads and equipment. It was one of the largest landslides in Canadian history and one of over 20 landslides to have occurred from the Mount Meager massif in the last 10,000 years. Although voluminous, there were no fatalities caused by the event due in part to its remote and uninhabited location. The landslide was large enough to send seismic waves more than 2,000 km (1,200 mi) away into the neighboring U.S. states of Alaska and Washington and beyond. Multiple factors led to the slide: Mount Meager's weak slopes have left it in a constant state of instability. The massif has been a source of large volcanic debris flows for the last 8,000 years, many of which have reached several tens of kilometres downstream in the Lillooet River valley., to the south. It is arguably the most unstable mountain massif in Canada and may also be its most active landslide area. And on the north side lies Downton Lake Hydro Reservoir, impounded by the La Joi Dam, the uppermost of the Bridge River Project dams. The earliest identified Holocene landslide was in 7900 BP (before the present, or read it as the number of years ago). Further landslides occurred in 6250 BP, 5250 BP, 4400 BP, 2600 BP, 2400 BP, 2240. BP BP, 2170 BP, 1920 BP, 1860 BP, 870 BP, 800 BP, 630 BP, 370 BP, 210 BP, 150 BP and in 1931, 1947, 1972, 1975, 1984, 1986 and 1998. These events were attributed to structurally weak volcanic rocks, glacial unloading, recent explosive volcanism and glacial activity. Those who dance with earthquakes and volcanoes are considered mad by those who cannot smell the sulfur. We begin to deal with BIG (MEGA) EARTHQUAKES at Simon Fraser University (foreground) Kulshan Stratovolcano© / Mount Baker Stratovolcano (background)©New Cascadia Dawn© - Cascadia Rising - M9 to M10+, An Intelligent Grandfather's Guide© next, ~ Images by Stan G. Webb - In Retirement©, An Intelligent Grandfather's Guides©Countdown to Earthquake Drill - International Great ShakeOut Day is on Thursday, October 20, 2022 at 10:20AM, and annually on the 3rd Thursday in October thereafter - - I grew up in small towns and in the North where the rule is share and share alike. So, I'm a Creative Commons type of guy. Copy and paste ANY OF MY MATERIAL anywhere you want. Hyperlinks to your own Social Media are at the bottom of each post. Creative Commons License
This work is licensed under my Creative Commons Attribution 4.0 International License.

Tuesday, December 11, 2018

ShakeAlert—Earthquake Early Warning. How does it work?

https://youtu.be/WWl3m4OyU44 [4:58 minutes]

IRIS Earthquake Science
Published on Oct 7, 2015
Reference prior post 

If you want to survive, HOW ARE WE GOING TO PAY FOR IT ALL ? - Senate Ways & Means Cascadia Subduction Zone Presentation Work Session, ...

SUMMARY:  If you want to survive, recognize that at first you will be all alone and uninsured.  We will need to take care of the after-effects of all of this ourselves.
STILL IT GETS PUSHED TO THE END OF A VERY BUSY AGENDA. This requires that we expect more from our leadership and that we elect serious, sober and somber people into office; NOT bratty, cute, entitled STUPID children.  One member of this committee WALKED OUT, even before this presentation had been concluded.
Washington State Senate Ways & Means Cascadia Subduction Zone Presentation Work Session, Feb 12 2017
https://youtu.be/gjbBx6tMfR0  [56:55 minutes]

ShakeAlert (www.shakealert.org ) is an experimental earthquake early warning system (EEW) for the West Coast of the United States and the Pacific Northwest.  ShakeAlert is a product of the US Geological Survey and its partners including the California Institute of Technology, University of California, Berkeley, University of Oregon, University of Washington, Eidgenössische Technische Hochschule Zürich (ETH), California Office of Emergency Services, and California Geological Survey. This animation, produced by IRIS in collaboration with University of California, Berkeley, describes how the system uses sensors to detect P and S waves to determine earthquake location and magnitude, and how that information can be sent to ShakeAlert users to give time to Drop, Cover and Hold On. For more earth-science animations:
http://www.iris.edu/hq/inclass/search...


Typical values for P-wave velocity in earthquakes are in the range 5 to 8 km/s. The precise speed varies according to the region of the Earth's interior, from less than 6 km/s in the Earth's crust to 13.5 km/s in the lower mantle, and 11 km/s through the inner core.
S-wave velocity tends to increase with depth and ranges from approximately 2 to 8 km/s in the Earth's crust, up to 13 km/s.

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