Alaska Dispatch News reports:
https://www.adn.com/arctic/2017/05/20/state-looks-for-help-fighting-mile-long-blob-oozing-toward-dalton-highway/
QuoteIn a race against time, state transportation officials plan to move a nearly mile-long section of the Dalton Highway so it doesn't get T-boned by a giant mass of frozen debris believed to have been oozing downhill like a glacier for hundreds of years.
The goal is avoiding a "catastrophic failure" of the highway if the nearly mile-long mass – a frozen debris lobe of mostly soil, along with ice, trees and other detritus – plows away the road, said Jeff Currey, a materials engineer with the Alaska Department of Transportation and Public Facilities.
... The lobe, essentially a slow-motion permafrost landslide, is up to 90 feet thick and 850 feet wide. It's expected to hit the road, where it climbs toward Atigun Pass in the Brooks Range, in the next four to six years, based on its 15-foot annual creep.
(https://www.adn.com/resizer/PoX9t-z5-NIY_BnwB9R9kdXxWmw=/1200x0/s3.amazonaws.com/arc-wordpress-client-uploads/adn/wp-content/uploads/2017/05/17104421/Frozen-debris-lobes-Dalton-Highway-03.jpg)
Better get on that Alaska meet!
What is the plan for this road, tunnel under the offending landscape?
Mike
Quote from: mgk920 on May 24, 2017, 09:56:51 AM
What is the plan for this road, tunnel under the offending landscape?
Mike
Another possible remedy: plow out the road before the slide hits it, installing a temporary bridge until a permanent one can be built -- so the permafrost passes under the road to the valley floor below (it looks from the picture as if some seepage/melting is getting down to the bottom in any case, so a pathway for such has been naturally established. Also, it looks like considerable foliage is growing out of the top of this "glacier"; the clearance on any bridge would have to accommodate that height as well as the mass of the ice flow. In any case, given the width of the flow at its maximum point (which will eventually end up down the hill!) the bridge structure would have to be quite long. Someone's going to have to pony up some serious bucks to take care of this problem without a long reroute; maybe just crossing the valley twice to bypass the whole mess might be a more prudent approach.
New suspension bridge!?
Quote from: mgk920 on May 24, 2017, 09:56:51 AM
What is the plan for this road, tunnel under the offending landscape?
Just move the road about 400 feet west. The blob is slow-moving enough, that fix should be enough for at least a quarter-century, lots of time to work out what to do next.
The highway is less than 45 years old, and who knows what'll be needed 25 or 45 years from now? That depends in part on the longevity of the Prudhoe Bay oil production complex and the pipeline it depends on, both of which have already exceeded their projected useful lives. A suspension bridge or tunnel are longer-range solutions than are warranted in the circumstances.
Quote from: Plutonic Panda on May 24, 2017, 09:04:07 PM
New suspension bridge!?
Hardly warranted for the traffic flow (and try getting the oil companies to foot the bill!).
Quote from: oscar on May 24, 2017, 09:17:02 PM
Quote from: mgk920 on May 24, 2017, 09:56:51 AM
What is the plan for this road, tunnel under the offending landscape?
Just move the road about 400 feet west. The blob is slow-moving enough, that fix should be enough for at least a quarter-century, lots of time to work out what to do next.
NOOOOOOO!....It's COMING......in give or take five years.....Run for your lives.......