Last week we did the annual lake levels trip, which is a whirlwind tour of the Dry Valleys that the stream team looks forward to every year. One of the Limno teams measures the elevations of the Lakes at the beginning of the season, and Stream Team is in charge of measuring the elevations at the end of the season. The elevations of the lakes are of interest because these lakes are closed basin lakes (they have no true outlet to the ocean). The input to the lakes is virtually entirely glacial meltwater, and the water outputs are evaporation of the open water on the moats, or sublimation (direct phase change from solid to gas) of the lake ice. Keeping a record of the lake elevations informs us on how much water is entering and leaving the lakes. The current trend is rising lake levels (more glacial meltwater in than evaporation and sublimation) and has caused a couple of camps to actually be moved uphill. The new Fryxell hut that was shown in a previous post is the result of rising lake levels.
This was an amazing day of flying because we got to fly up the Taylor Glacier to Lake Joyce and Lake House (shown below).
|View over the Laybrinth|
|Don Juan Pond|
Mikey and I had a day trip yesterday to another unique place called University Valley. We weren't on the schedule, but were told to be ready because if they were unable to fly up to Erebus they were going to fly our mission instead. We were notified around 11:00 AM that we were flying at Noon so we scrambled our gear and headed down to the helo hanger. The flight out along the sea ice was pretty spectacular. The majority of the McMurdo sound sea ice has broken up and drifted away, leaving a beautiful open bay between McMurdo and the Dry Valleys. The helicopters are not allowed to fly over open water, so luckily for us they have to skirt the edge of the Ross Ice Shelf (this is extremely thick ice that does not clear out of the sound from year to year) which adds quite a bit of flight time to get out to the valleys. Also convenient for us is the orcas like to patrol the edge of this shelf hunting for their next meal. So we got to do a bit of whale watching on the way out.
|Sea ice breaking up. If you look really close and have a super high definition monitor you can see an orca popping up to breathe. It is 2/3 the way across the photo from left to right and in the little gap of open water amongst the ice sheets.|
|Ventifact in University Valley|