Dive tending

Wed 13 Jan 2010

This morning we had a great lecture on Geology and Oceanography from Dr. George Somero. Some details I have been wondering about were clarified...here are some dates that helped with that: 41 ma the Drake Passage opens up and Antarctica and South America separate; 33.5 ma Antarctica and Australia separate; 22 ma the Drake Passage deepens and the Antarctic Polar front develops (a current around Antarctic), acting as a barrier to colonization (by organisms); 14-12 ma sea ice forms. The ice shelves can be 400-500 m thick, cover 44% of the coastline, and are 80% below the water line. These defining features of the ice shelf shape the habitats here.

In the afternoon I had the opportunity to "tend a dive" for Dr. Jim Leichter (professor at the UC San Diego Scripps Institute of Oceanography). He is the "professorial TA" for our Biomechanics module in the course (remember that for the course we are split into 5 modules). Diving under the ice, as you might imagine, is quite technical and intense (even though Jim swears to me that diving in Bodega Bay, CA in a wetsuit is more hardcore than the diving he is doing here…). It is really important, maybe mandatory (?) to tend dives here before you can get cleared to dive yourself. For this program, the participants are not permitted to dive because there is really not time with everything we are doing to get cleared and dive, but hopefully I will be back here, and I will dive then. It would be so amazing. It is hard to be here and only get to help with dives, but it does make sense given the nature of our program.

Here is a pic of drysuits hanging in the dive locker. Drysuits do just what they sound like they do...keep you dry. A wetsuit traps a layer of body-warmed water between your skin and the neoprene wetsuit, and the warm water keeps you warmer than the water and the neoprene wetsuit insulates your body. A drysuit itself does not provide much in the way of insulation, but underneath the drysuit you wear fleece and/or down clothing (in Antarctica), and this is what keeps you warm. The <20m water temperature here right now is approx. -1.8 degrees Celsius.....cccccooooollllddd.

The dive tenders job is to help schlep gear (here we are dragging gear out to the ice hole on sleds),

 Help the divers get their gear on (especially the gloves),

Keep an eye out on gear as the divers enter the water (the second picture is of Dr. Jim Leichter),

And put the ladder down once the last diver is down. The ladder and buckets are attached to the ice with ice screws before the divers descend.

Then you wait….and it's cold so of course you have to keep active...

Once you see bubbles you get prepared to help the divers get their gear, any organisms they collected, and themselves safely out of the water and warmed up.

Usually you have a hut that sits over the ice hole to dive from, but this time of year the huts have all pretty much been brought back to the station.

Here is a picture of a hut.

After dive tending I went back to the lab for a bit of work, then we had dinner and an evening lecture by Paul Morin from the U of Minnesota. His crew is mapping Antarctica...seriously. It is way cool. Check out this site for more information: http://www.agic.umn.edu/. I actually met Paul in LA when we were about to board the plane for Sydney and a woman on his crew sat across the aisle from me on that flight, so I got a lot of the scoop on the origins and status of the project. Then Paul and I ended up sitting beside one another on the Sydney/Christchurch flight so I got to find out even more. Paul and his crew have mapped 40-60% of the continent at 50 cm resolution (to give you an idea of this resolution...you can see individual penguins in the images). They use images from cameras that are mounted on satellites orbiting the earth. These satellites are not used specifically for this method (they are often used by the military), but because of the orbiting paths, the satellite-mounted cameras pass over the poles 4 times per day. Paul and his crew go out and ground truth the images during their field season and take additional pictures in the Dry Valleys. Pretty neat stuff.

I got to move into my permanent room today too, and my roommate is out in the field, so I get a solo room for now....which is pretty rare. My new dorm is 2 person occupancy rooms (I was in a 5 person occupancy room) and 2 rooms share a shower/washroom, but each room has it's own sink. I apparently moved into the nice dorms which are typically reserved for those with more than 1 year on the ice (209 for those Antarctic buffs out there), so I am feeling lucky. Honestly though, I would be happy to sleep in just about any room or tent if it meant I got to be here. I am having one of the most fulfilling experiences in my life in so many ways.

Still grinning ear-to-ear.