Monday, May 30, 2011

Yakutat Glacier, still falling apart

We are just back from Yakutat Glacier, one of the most rapidly retreating glaciers in the world. These icebergs came off the glacier last September and are currently stuck on an old moraine in the lake. The lake is generally very deep (over 300 m), but at this location an old sill keeps icebergs from floating down lake.

Yakutat Glacier has lost several square kilometers of surface area in the past few years, and no end is in sight. Large rifts are still forming on its floating tongue and further retreat is guaranteed.

Last year we measured the ice thickness using an ice penetrating radar, and we found that all of the glacier base is very close to sea level. Harlequin Lake, into which the glacier now calves, will keep growing for quite a while!

Friday, May 13, 2011

Icy Bay

Icy Bay is located along the coast of Alaska, northwest of Yakutat. It must be among the most amazing places on Earth. My colleague Chris Larsen has led a project there to study tidewater glaciers and icequakes. We went there to help him rescue a camera. Glacier pilot extraordinaire Paul Claus got us there in his Supercup

There are several glaciers entering the bay. We went to Yahtse, which is among the few advancing glaciers.
It is quite overwhelming to stand in front of this large and unstoppable mass of ice.

The small orange box contains a camera to monitor the glacier advance. We came just in time to move it ahead of the advancing ice.Back from a successful mission, Chris is contemplating the vastness of the place...
The mountain goats love the steep slopes here. They seemed to be about equally curious about us as vice versa.
And on the flight back: A nice view of Mount St. Elias and the Tyndall Glacier. You are looking at 5400 m (18,000 ft) of elevation difference in this picture!

Bering Glacier surge

Last week we did some flying in the Wrangell St.Elias mountains. The main purpose was to test an airborne radar. In the process we got to fly over America's largest glacier: the Bering Glacier. It is currently in a full surge and its surface is heavily crevassed.

The glacier is flowing several times faster than normal and is now in the process of advancing into a proglacial lake. Icebergs breaking off the glacier almost completely cover Vitus Lake now:

The glacier is heavily crevassed along its entire lower reach. Here is a shot looking up. The mighty St. Elias (about 5400 m or 18,000 ft above sea level) is in the far back (center), and Mt. Miller on the left: