Under the Ice
Most of last week was spent sitting around Pine Island Bay doing CTDs while the AutoSub (a small autonomous yellow submarine) was exploring under the ice. It is seven meters long, powered by 5000 D cell batteries (manually inserted).
I haven’t mentioned AutoSub much because we were waiting to see how the project went. It has done very well, including surviving an underwater bump with some ice that left a dent on its nose and still making it home. It has done multiple missions under the ice, some of them almost 30 hours in length and up to 150km total distance. It maps the ocean floor and the bottom of the ice shelf, in addition to sampling water properties.
Tonight while it is getting repaired we’ve had the opportunity scout the ice conditions to the west, where we will head next once AutoSub operations are complete. We sailed for 50 nautical miles near the Thwaites Glacier Tongue at location (lat:-74.3766 lon:-105.4643). For the past two hours we have been sailing along the edge of a massive piece of Pine Island Glacier that broke off in 2007, drifted here, and has been stuck on a high bottom feature for the past few months. This iceberg is 10s of miles long and covered a large chunk of the horizon while we were still quite far away from it. Now, right next to it, it towers over us and fills our view on one side.
On the other side is open ocean with bits of ice containing dozens of penguins (mostly Adelie), and the occasional seal. Throughout the night we’ve sailed past hundreds of penguins.
The sun is getting lower each day as the earth rapidly tilts from solstice toward equinox, which means the colors are getting better. The solar minimum is still about 30 degrees above the horizon, and occurs around 4AM ship time, right in the middle of my shift.
location: lat:-74.3766, lon:-105.4643
