Tuesday, July 9, 2013

Black Rapids lake drainage

This was a quick trip for me to help set up some surveying instruments on Black Rapids Glacier. We were here to watch the effect of a draining lake. From past measurements we know that the glacier can start flowing 2-4 times faster when water reaches the base. We wanted to see whether such a speed-up can also draw in ice from a big tributary glacier.

Aurora Lake, full to the brim, and ready to drain. This is the biggest of the marginal lakes.
The upper Black Rapids Glacier has many of these potholes, old crevasses that often fill with water and then drain.

Looking up Black Rapids Glacier
Mt. McGinnis

Our surveying equipment: An automatic theodolite and a precise radar that allows us to measure deformation fields in the entire field of view.


While checking out various instruments, we had an opportunity to hike around the glacier. It's always nice to see the signs of life in the harsh conditions of the mountains.
A plugged up moulin; this hole leads right to the bottom of the glacier!

A ptarmigan nest ...

... and mama ptarmigan whom I inadvertently chased off her nest.

A panorama showing the Loket tributary as it enters the main valley of Black Rapids.
video
I recorded this video as I hiked out the glacier. Near the glacier front, water comes up from underneath the glacier and creates these big waves.

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