Jokulhlaup
WRANGELL-ST. ELIAS NATIONAL PARK
Icelandic glacial word describing one of nature’s most powerful displays of beauty
Hidden Creek Lake on the west side of the Kennicott Glacier
Jokulhlaup
A Jokulhlaup is an Icelandic term describing a glacial outburst flood. What the heck is that?
Glaciers typically have lakes at their terminus and at junctions with valleys as in the above photo. These lakes form due to melting of the glacier ice during the warmer months of summer and by blocking the flow of a creek that slams into the side of the glacier. Since water is warmer than ice it will continue to slowly melt and burrow deeper and deeper through the side of the glacier. Glaciers are not just solid chunks of ice. They have a series of holes and tunnels running all along the depths of the ice that act as a sort of internal plumbing system. So as the water from a lake melts deep enough through the side of the glacier it can expose an opening deep within the glacier. The result will then be a rapid draining of the lake as its water gushes through the system of tunnels deep within the ice. Eventually the water will make its way to end of the glacier and cause a rapid swelling of the creek or river pouring out of the terminus. This glacial outburst occurs quickly and typically lasts for 2-4 days. And depending on the size of the lake and the volume of water the jokulhlaup event can cause flooding that is quite dangerous and destructive.
Hidden Creek Lake full of water before the Jokulhlaup
Before the Break
Hidden Creek runs into the western side of the Kennicott Glacier where it is initially damned up to form a big lake. Hidden Creek Lake is full of icebergs and is quite beautiful to see.
Beached icebergs in a drained Hidden Creek Lake after the Jokulhlaup
After the Break
Every year like clockwork, the damn breaks in mid-July and Hidden Creek Lake drains over the course of 1-2 days.
When the jokulhlaup is finished the drained lake bed is now full of beached icebergs. Walking around the giant ice towers is an otherworldly experience!
Water gushing out of the side of the Kennicott Glacier
Increased Glacier Activity
Getting to Hidden Creek Lake to watch the water drain is very difficult because it is a long distance away from McCarthy/Kennecott (the closest towns) and there is no road access. Also, there is no way to predict the exact day that it will happen.
But the most exciting activity occurs within and around the Kennicott Glacier anyway. As the enormous volume of water gushes through the plumbing within the glacier it eventually emerges at various points along the sides and terminus. Impressive outbursts of water create flooding events that are exciting to watch!
Kayaker taking on big waves in the massively swollen Kennicott River
Paddler’s Delight
The most notable result of the jokulhlaup is the rapid swelling of the Kennicott River. The increase in volume and flow of water creates adrenaline-surging rapids that local kayakers and packrafters simply cannot resist! Paddlers take advantage of the unusual conditions to run laps down the river during the evening when the flow and volume generally hit their peaks.
Locals gather to celebrate the annual Jokulhlaup on the footbridge
Party at the Footbridge
Locals gather at the footbridge in McCarthy to celebrate this yearly display of the awesome power of nature.