Muldrow Glacier surge

National Park geologist Mike Loso had noticed a while ago that the Muldrow Glacier north of Denali was showing signs of surging. My colleague Mark Fahnestock started tracking it on satellite imagery and he had figured out that one tributary had been flowing much faster than normal. Last weekend we had an amazing fall day, so I got a chance to fly my whole family down and check it out.

This is the remote sensing analysis. The fastest part is in the Traleika tributary (over 3 m/d) but the fast flow continues into the main branch of the glacier.

 Here are some pictures:

Denali is an imposing presence, even from a long distance

Muldrow Glacier. The Traleika tributary is the second one entering the glacier from the South (left in this picture)

Traleika tributary junction

Looking up the Traleika with extensive crevassing.

The rapid flow causes chaotic shear margins

The upper Traleika Glacier

Some small tributaries seem to have become engaged in the surge

Shear margin

Looking downstream from the Traleika into the main branch of the Muldrow. The Traleika branch is most obviously affected by the surge, but fast flow clearly extends down the main branch, as indicated by the flow speeds.

The glacier tributary junction. Note the crevassing below the junction.

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Mt. Foraker