ALASKA’S HUBBARD GLACIER IS STILL ADVANCING, BUT AT A SLOWER PACE
By Climatologist Cliff Harris
Our Yukutat, Alaska correspondent Frank "Skip" Ryman has updated his information for our readers concerning the advancing Hubbard Glacier that’s threatening the town where he’s the city manager.
For much of this past spring, Skip told us that the glacier was advancing at the rather astounding rate of two meters (7 feet) per day.
As Skip reported in late April, "the Army Corp of Engineers has become involved with the growing Hubbard Glacier because when it reaches Gilbert Point it will close the Russell Fjord creating a 30-mile-long lake that will have ‘significant negative impacts’ on our community."
In Skip’s June 16th e-mail to me, he reported some late spring changes to the advancing Hubbard Glacier. Here is his report:
"The glacier’s annual advances are characterized by a late Spring slowdown and, while it is early in the phase and I can’t say for certain, that is exactly what appears to be happening.
Russell Fjord is the depository for over seventy freshwater streams which feed a current that gradually intensifies as the gap between the glacier and Gilbert Point narrows. The fast current erodes the glacier’s protective moraine in Disenchantment Bay causing it to calve and pull back.
However, while the glacier retreats from Disenchantment Bay, it appears from recent aerial photos to be continuing its advance into the fjord and should eventually (maybe as early as next year, but almost certainly within the next thirty or forty years) wrap itself around Gilbert Point and turn the fjord into a glacier formed lake.
If you are monitoring the Corp’s website, you may notice some erratic data as large calving ice flows traverse the gap and interrupt the laser. Once the fjord is dammed, those seventy streams mentioned earlier will cause its level to rise. When it has risen an additional 132 feet, it will eventually overtop the dam and form a new thirty-three thousand cubic feet per minute river that will join seven thousand cubic feet per minute of existing Situk River and braid its way to the Gulf of Alaska.
As spectacular and exciting as that event will be to witness, it will have a significant negative economic impact on our borough as it disrupts the sensitive spawning cycles for five varieties of Pacific Salmon that spawn there as well as the world class Steelhead Trout run the Situk supports.
The Army Corp, with the assistance of the USGS and the USDA Forest Service, is breaking from its traditional role and is assisting us in evaluating a variety of economic mitigation opportunities and we are very grateful for their support."
On behalf of our readers and myself, I wish to tank Skip for his Hubbard Glacier updates. We will feature these reports on a monthly basis throughout the rest of 2009 and beyond. Stay tuned.
