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.

Friday, October 21, 2016

Plate Tectonic Evolution of North America - Scotese Animation

Plate Tectonic Evolution of North America - Scotese Animation
(MA or Ma (mega-annum) is a million years)
https://youtu.be/2yKNhbY3Nbk (4:59 minute YouTube Video)

Published on Dec 14, 2015
by Christopher Scotese The PALEOMAP Project Channel by Christopher Scotese has more than 50 computer animations showing the plate tectonic evolution of the continents and ocean basins during the last billion years.


This animation shows the plate tectonic and paleogeographic evolution of North America from 200 million years ago to the present-day. North America was originally part of thee supercontinent of Pangea. About 200 million years ago, Pangea rifted apart. To the east of North America, the Central Atlantic Ridge [Mid-Atlantic Ridge (MAR)]
The Mid-Atlantic Ridge (MAR) is a mid-ocean ridge, a divergent tectonic plate or constructive plate boundary located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world. In the North Atlantic, it separates the Eurasian and North American Plates, whereas in the South Atlantic it separates the African and South American Plates. The Ridge extends from a junction with the Gakkel Ridge (Mid-Arctic Ridge) northeast of Greenland southward to the Bouvet Triple Junction in the South Atlantic. Although the Mid-Atlantic Ridge is mostly an underwater feature, portions of it have enough elevation to extend above sea level. The section of the ridge that includes the island of Iceland is also known as the Reykjanes Ridge. The ridge has an average spreading rate of about 2.5 cm per year.[1]
With the formation of North America, the North American Tectonic Plate is now colliding with the Pacific Tectonic Plate – and it's leading edge plates. The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At 103 million square kilometres (40,000,000 sq mi), it is the largest tectonic plate, The north-eastern side is a divergent boundary with the Explorer Plate, the Juan de Fuca Plate and the Gorda Plate forming respectively the Explorer Ridge, the Juan de Fuca Ridge and the Gorda Ridge. In the middle of the eastern side is a transform boundary with the North American Plate along the San Andreas Fault, and a boundary with the Cocos Plate. The south-eastern side is a divergent boundary with the Nazca Plate forming the East Pacific Rise ....
> > > > > > > 
Seismic Hazard Maps for the National Building Code of Canada – past ...
https://www.iclr.org/images/2_-_Adams_Toronto_Workshop.pdf
Jan 13, 2012 - Geological Survey of Canada,. Natural Resources Canada, Ottawa, ... Size described by magnitude (one magnitude per earthquake!) Effects described by ... Magnitude-recurrence statistics near Toronto ... Probabilistic treatment of Cascadia. • Integrated .... Seismic hazard estimates are improving. More data ...
https://www.iclr.org/images/2_-_Adams_Toronto_Workshop.pdf\
Cascadia Magnitude-recurrence for complete rupture events ~ Synopsis
J Adams 20120113
[ever wonder why eggheads* use big words, just so the rest of us don't understand? Used here, prototypical is used to indicate that someone or something is a very typical.
(Over the last 10,000 years ~
“10,000 year history (we have one sample of the 1/10,000 year event!). Assume that each rupture of interest to Canada is a complete, end-to-end (IE. all M~9**, not some M9 + many M~8) Use time interval * plate tectonic rate to get the slip per event
magnitude Protypical event happens every 550 years, ruptures length of 1020 km and width of 125 km, has slip of 25 m and has magnitude of 9.3
Events range in magnitude from 8.5 - 9.1 or 8.9 - 9.5 depending on input assumptions – but nearby seismic hazard is not very sensitive to exact magnitudes when earthquakes get this big

Boy, you can say that again!***  - Stan G, Webb

*egg·head ˈeɡˌhed/ noun
informal derogatory
plural noun: eggheads
  1. a person who is highly academic or studious; an intellectual.
synonyms:
 intellectual, thinker, academic, scholar, sage;
bookworm, highbrow;
expert, genius, mastermind;
** Here I believe the author is using the tilde ~ as a symbol for approximation. As we all learned in grammar school arithmetic, the formal approximation symbol looks like two tildes on top of one another (≈). I suppose the author could just have written, I don't know, but around M9, or M9±.
*** Following years of academia and study, when I was in practice, I would try to propose different options and plans and discuss those with my clients. After spending hours explaining several complex options, some would say “they just still did not understand; but, since I was so compelling, indeed, passionate in my beliefs, they told me to go head with the plan I had outlined”. They know that I always had their best interests in my heart and mind. Now, I said to myself, that is not how I want to practice. So I went back to night school to learn how to communicate, loosing all of that professional jargon. It took me 2 years, post-graduate. My clients all complemented me on my efforts. For the first time I made things clearer and easier for them to understand. Later was widely engaged as a keynote speaker and published author. Albeit some were tough, dark years.
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