Posted on 01/19/2013 8:13:22 AM PST by SunkenCiv
The White River Ash blasted from giant eruptions somewhere in today's Wrangell-St. Elias Mountains, drifted as far away as Ireland and Germany...
Ash from the White River eruptions, possibly from 15,638-foot Mount Churchill or at least close to it, left an easy-to-see mark on eastern Alaska and northwestern Canada. Explorer Frederick Schwatka documented the ash in 1885 in his book "Along Alaska's Great River." People driving the Klondike Highway pass more than two feet of the whitish grit exposed in road cuts on their journey through the Yukon Territory...
Froese and Jensen traveled in the Yukon to a branch of the upper White River... they cored the grey trunks of spruce trees smothered by White River ash. Using radiocarbon dating, they found the trees died in the year 843 AD, give or take about 20 years.
Recently, U.K. researchers located an ash layer familiar throughout Europe that scientists first found in Ireland peat bogs and in a Greenland ice core. They determined that it came from an eruption that happened around 846 AD. That date, along with a familiarity to the ash, caught the attention of Jensen and others.
When Jensen analyzed the ash from Ireland, she found it had the same geochemical signature as the White River Ash, including a unique high content of chlorine...
Around that time, two incredible eruptions blew from the heart of the Wrangell-St. Elias Mountains from somewhere near Mount Churchill and Mount Bona, two neighboring peaks separated by a high saddle. The ash in the Irish peat bog is from what scientists call the "eastern lobe" of the eruptions that created the White River Ash.
(Excerpt) Read more at gi.alaska.edu ...
Duane Froese of the University of Alberta in a forest of stumps smothered by the White River Ash around the year 843 AD. Froese is pictured in the Yukon Territory, close to the Alaska border and Natazhat Glacier in an area downwind of the great White River eruptions, which spewed from somewhere near Alaska's Mount Churchill. Photo courtesy of D. Froese.
Scientists actually doing science bump..
Why am I not surprised?
:’) The surprising thing is, I finally post a topic about a volcanic eruption that left massive traces — and during historical times at that — and just three of us show up. :’o
Aerial View, Wrangell-St. Elias National Park, Alaska
Whoa! My parents lived on Wrangell Island before I was born, so this is an awesome photo for me. Thanks for posting it. ;o]
Quality, not quantity!
You are so awesome! I may not comment on all your pings, but rest assured, I read them all. Some are obvious and don’t really need comments. Others are old news (to me) but I enjoy reading about them again.
Thanks for all the work you do!!
I wonder how thick the white ash layer in Europe is.
Thanks!
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