Glacial dam on Mendenhall Glacier bursts, prompts flood watch
Yesterday a glacial lake on the Mendenhall Glacier broke free and the waters are rising in Mendenhall Lake and Mendenhall River.
The National Weather Service has instituted a flood watch throughout today and Friday.
As of 4 a.m. Mendenhall Lake was at 6.2 feet. The lake is expected to crest at 9.5 feet on Thursday night. Flood stage for the lake is 9 feet.
Mendenhall River was at 9.16 feet this morning and is expected to crest near flood stage at 11.5 feet on Thursday night.
“If the river level gets to those levels that means View Drive, the houses on it, may see some minor flooding,” said Richard Lam of the National Weather Service Juneau office.
“The Mendenhall Lake Spur Road between Skater’s Cabin and the West Glacier Trail, that section may be under water if the lake level gets to what we forecast it for. So some minor flooding along Mendenhall Lake Spur Road,” Lam said.
The Mendenhall Glacier Visitor Center is taking precautions, warning hikers and kayakers to be aware of their surroundings, and not get too close to icebergs or the glacier.
“We will be on alert for public safety at the visitor center and other areas such as the Mendenhall Campground. We will monitor conditions at the lake as best we can by observing the glacier and icebergs. The National Weather Service has been keeping us informed,” said Laurie Craig, lead naturalist for the Mendenhall Glacier Visitor Center.
“There was a series of large calving events on Tuesday, July 3 around 5:00 a.m. Today the lake is filled with icebergs including some huge pieces that are noticeably moving around the lake,” Craig said.
“Water is draining rapidly from the right side ice cave but no waterfall is visible, which we were able to observe last year,” Craig said.
Last year a similar event happened when a glacier lake burst in Suicide Basin. Water had built up and released over a four-day period from July 19-22, according to information from the University of Alaska Southeast.
The glacial lake was located in Suicide Basin which is approximately 2 miles up the Mendenhall Glacier’s east side. The event is actual called a Jökulhlaup (Yo-ko-laup) which is an Icelandic term for the glacial outburst flood.
For photos of last year’s event check out this gallery by Eran Hood, Associate Professor of Enviornmental Science, Department Chair at UAS.