“Space is hard.”
-International Space Station Astronaut Scott Kelly
“Antarctica is also hard. And so are robots.”
“……….. but not always.”
-Andy and Tiegan
It’s been up and down here on the seventh continent. Andy, Britney, and I were able to get out to our first field site yesterday. It’s at the edge of the sea ice, about 100m from the ice shelf near New Zealand’s Scott Base. This is an important transition between glacier ice flowing under its own weight off the continent, and ice that forms directly in the water column. Shelf ice can be anywhere from 10’s of meters to over 3 km thick, whereas sea ice is typically only a few meters. In the water column, the solid sea ice that we walk on (columnar ice) is underlain by platelet and frazil ice. Frazil are very small blades of ice that form in the water column and “snow” or float upward. Platelets are exactly what they sound like: little plates of ice that generally stick to the bottom of the surface ice. When they clump together they still have space between the plates, filled with water. Layers with tightly packed platelet ice and the beginnings of columnar ice are called marine ice. Therefore, when we drill through the sea ice we also need to drill through the platelet ice and clear it out so we can deploy Icefin into the ocean water without it getting caught. Platelet and frazil ice exist beneath the ice shelf as well, although this season we are primarily working on sea ice.
Yesterday we re-drilled a 30 cm diameter hole, completed a CTD (conductivity temperature depth) profile, ate some cold pizza with beautiful views of Mt Erebus, and then helped setup our fish hut at the Scott Base site. The first step is clearing snow off the ice using a small bulldozer. Then Andrew and Mel drilled an approximately 1 meter hole through the ice.
Plunging the platelet ice out and clearing it from the site was a lengthy process, but the crew here are experienced and efficient. Once that’s done, they dragged the fish hut (a small cabin on sled tracks) over the hole and the carpenters, Ryan and Ben, got the stove working. The fish hut is kept warm for shelter, comfort, and to keep the drill hole from refreezing.
With our new little base set up on the ice, project Bravo 041 headed back to the Rock with all souls accounted for; over. <— I’m learning the radio lingo and it’s going super well.
Icefin, meanwhile, is getting very close to being ready for deployment. The robot has been bottled in its pressure vessel and is currently undergoing full systems tests and a water tank test. While it will be ready to deploy tomorrow, the weather has other plans.
McMurdo specifies weather in terms of ‘conditions’, which are linked to the operations of the base. Regular operations occur in Condition 3, or just Con 3. It doesn’t have to be pleasant weather, but it means visibility, wind speed and temperature are sufficiently good for people to safely navigate and spend time outside. Con 1 is when visibility falls below 30 meters (100’), wind speed is greater than 102 km/h (55 knots, 63 mph) or air temperature is less than -73 Celsius (-100 Fahrenheit) for one minute or longer. Currently we are in Con 2 in McMurdo, but the sea ice is in Condition 1 due to poor visibility and strong winds coming from the south. That means no travel is allowed on the ice, but we are able to move between buildings on base. Storms are expected to continue until Monday.
Here’s hoping it will clear up soon so we can take the beast for a spin under the ice!