Tuesday, February 2, 2016

Back to the Big City

We arrived in McMurdo on Saturday which was a bitter sweet day.  We had to leave Ray, Renee, and the Valley that has been our home for the past three months for the big city.  The plus side was that upon returning we were able to take a shower and change into clean clothes, which really is an amazing feeling after a while without either.  This week we have been busy returning gear to the work centers we borrowed them from, and storing equipment for next year's team.

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).

Lake Joyce
Lake House
Then we crossed up and over the Western Asgard Range into the Western Wright Valley near the Air Devron Six Icefalls and the Labyrinth.  The Air Devron Six Icefalls are a truly spectacular sight.  I wish I could have captured a picture of them, but it just wouldn't have done them justice throught the helicopter window. The icefalls are an area where the ice from the polar plateau cascades down a massive dolerite and sandstone cliff of hundreds of feet and terminates at the bottom of the cliff to form Upper Wright Glacier.

View over the Laybrinth
Down valley of the glacier there is a system of canyons called the Labyrinth.  These canyons have formed from what is believed to be massive glacial outburst floods.  This is where glacial meltwater pools up over time, usually dammed by ice or sediment, and in one catastrophic event it drains the melt pool.  As you could imagine this process has carved out some amazing canyons through the Western Wright Valley.  This place is reminiscent of photos I have seen from southern Utah.  Here is a photo of us flying above the Labyrinth.  Renee said it might be the prettiest view she has ever seen, and I would have to agree.

Don Juan Pond
After flying through this area we landed at the saltiest body of water in the world, Don Juan Pond.  I asked a geologist what the theory is concerning the high salinity of Don Juan Pond and he basically said that you have water picking up salts from the surrounding landscape and dumping into the pond.  The water evaporates and leaves the salt behind.  It was a strange place.  The water was only a couple of inches deep, the bottom sediment was covered in salt that had precipitated out of the water, and there were large rocks placed about everywhere like a sculpture garden.  I could have gotten really artsy with some photography here and Forrest got a great shot.  Unfortunately this is the best one I was able to take.  Yet another place in the Dry Valleys that feels out of this world.

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.
Once we hit the valleys we cruised up the Taylor Valley and hit some strong headwinds once we got up to the Taylor Glacier.  It was another half hour of flying up the taylor glacier to finally arrive at University Valley.  Once we arrived we went and downloaded some data off of a meteorological station and did a little exploring.  This was probably the most other worldly spot I had been to yet.  It is fitting that the team trying to film shots for a TV series called "Red Planet" is trying to get up there.

University Valley
Ventifact in University Valley
Today has been pretty non-eventful.  We are nearly done with our field work, except for one possible trip to the penguin rookery at Cape Royds which I am really hoping for.  Other than that we have just been cleaning up and trying to stay busy.  Most of us don't leave until February 8, so we have some down time which has been nice.