In the time since the last post we’ve been busy alternating diving days and days for analyzing data, adjusting, and planning missions. We’ve been able to improve our navigation strategies and better estimate the location uncertainty when we operate in different travel modes (ex: driving the robot manually or letting the vehicle drive itself between waypoints).
All of this work at the Scott Base Shelf Site allows us to start to image the transition between sea ice, where our fish hut sits, and the ice shelf. The thickness between these two units is roughly 3m for the sea ice versus about 25m for the edge of the shelf here. There’s also a big change in the ice provenance – which just means “where it comes from”. Shelf ice is glacial ice, from the continental ice sheet, that has flowed off the continent and over the ocean. It floats, but is still attached to and sourced from land. As we have covered in previous entries, sea ice forms in the water column and floats up.
Photo credit: Andy Mullen
After several dives near Scott Base we have switched operations to Erebus Glacier Tongue, which has some important logistical challenges. It’s a 2-3 hour drive each way in the PistenBully, or a little over an hour by snowmobile. There’s limited communications over radio, so we have to keep in touch with McMurdo by satellite phone. The sea ice is significantly more cracked and exposed than it is near town, because of the glacier tongue interacting with the sea ice. And the tongue itself is quite unstable, making it impossible for us to go anywhere within about 100m of the glacier. Perhaps most importantly, we deploy here using a large metal A-frame that sits over the hole and adjacent to an operations tent with room for about half the team. Setting these structures up is not trivial, and you’re fully exposed to the weather while doing so.
Photo credit: Britney Schmidt
We certainly felt the weight of those challenges trying to get our camp setup. Attempt 1: we packed up with all of the necessary gear (so much stuff!) to create a base out of nothing, but halfway there had a problem with our PistenBully wheel and had to turn around. Attempt 2: we got up bright and early, but still ended up getting turned around by bad weather after only a handful of hours on site. Attempt 3: we finally got the A-frame installed and the hole excavated. After 3 tries, we were ready to dive the following day. #Antarctica, right?
Photo credit: Dan Dichek
When we did make it out we had the pleasure of spending the day with the crew from NOVA (https://www.pbs.org/wgbh/nova/), as they’re filming a series of videos about science and life in Antarctica. Luckily the weather cooperated with clear sunny skies and mild temperatures, which is preferable when operating camera equipment.
Photo credit: Andy Mullen
We’ve also gotten lucky with the local macrofauna: our drive to the glacier tongue takes us near a couple packs of Weddell Seals.
Photo credit: Frances Bryson
In the interim, McMurdo continues to be an awesome place to work out of. Folks are certainly enthusiastic about Halloween, and only a couple weeks left until Thanksgiving! Smaller events mark the community calendar, too, like a craft fair, salsa classes, and group meditation. Now who said there are no polar bears in Antarctica?