Island Days (Part 1)- Geologic and Historical Constraints (GHC) on Glacial Advance and Retreat
text and images by Victoria Fitzgerald
As I face the glossy orange wall of the Louisiana born ship, the Nathaniel B. Palmer, I prepare to step off the deck and take my first step down the iced over rope ladder. I am getting off the ship to provide technical assistance and optically stimulated luminescence (OSL) field expertise to PhD student Scott Braddock and Master’s student Meghan Spoth, representatives of the Geologic and Historical Constraints (GHC) team. My mind races from fear to focusing on helping them accomplish their mission: collect organic material (e.g. bones, algae, fur, seashells) for radiocarbon dating of raised beaches on multiple islands in the Amundsen Sea. Their efforts will provide glacial-geology modelers with data to determine if modern Thwaites Glacier retreat rates have occurred in the recent past and if it was able to recover. This information will help us better predict sea level change. I quickly absorb the importance of the project before my mind jumps to the excitement in thinking that I will touch Antarctic land and not just sail near it for 8 weeks. I take a deep breath from beneath five layers of heavy winter clothing and bury my fear of small boats and the ocean. I think: Just step down, away from the comfort of the ship, and get on the Zodiak.
After we arrive, we stumble across a frozen rocky surface carrying shovels, survival bags, and other sampling equipment, looking for a place that won’t interfere with the wildlife, and is above the tides which could wash our gear out to sea. We find a high spot on some rocks and quickly change out of our float coats, the loud orange life vest parkas that (hypothetically) would save our lives if we fall out of the boat into the freezing water. We shimmy into additional dry layers for the long haul of beach combing and hole digging.
To say the wind hurts is an understatement. It’s -10°F outside and the wind chill is around -20°F; I look around and take in what will be the next 12 hours of my day. This isn’t an island for relaxing and drinking margaritas. It’s a stone desert filled with ice, penguin poop, and Adélie penguin parents who are running in all directions away from their tenacious chicks who are begging for another snack. I immediately identify with their struggle, having three kids of my own with insatiable appetites and the energy of a thousand Suns.
Oh, and there are Skuas, the equivalent of angry giant seagulls who dive bomb your head anytime you are near their chicks…which is often. They are everywhere and nowhere. The chicks are the same color as the rocks and it is difficult to see them until you train your eyes for their movement. This is my new priority.
I take a selfie in true millennial fashion and cover up my face. No time to correct my reflection in my sunglasses: my hands have started burning and my phone isn’t recognizing my finger anymore. We make our way to the beaches that Scott has recon’d using what we think of in the U.S. as old satellite imagery, thanks to the internet’s ease of access. Out here we are using two to three-week-old data. Every now and then we receive new ice imagery, but with limited bandwidth on our satellite internet comms and the ice constantly moving, we rely heavily on our experienced Captain and crew to steer us clear of danger and navigate us safely to our projects. We all hold our breath, hoping the beaches are ice free for sampling.
Good news! The imagery was fairly accurate. Even better news: we are further into summer and the beaches have even less ice than we expected. There are four of us, and Scott issues our marching orders plus a quick demonstration on what to look for before we split up into two teams on the hunt for organics. I’m with Scott, while Meghan wanders across the ridge line with Dr. Kelly Hogan, a British Antarctic Survey Geophysicist who has experience in this type of sampling.
As we start, I feel like we are playing a game, a great scavenger hunt, only here it is literal (and littoral!). Surface material can be difficult to find as the islands are littered with penguin remains. The bones of the recently deceased penguins or seals are not good samples, we need hundred to thousand-year-old bones, the ones that are bleached white, growing algae, and spongey looking instead of smooth nonporous surfaces you might find in that piece of chicken from last night’s dinner. After a few minutes of beach combing with little luck, Scott announces he will start digging and I should prepare sample bags.
We make quick work of all the loose cobbles and start using them to hold our gear and samples in place as the wind just won’t stop. Soon we have around 15 samples from at least 2 raised beaches. We are pretty proud of ourselves and decide we should check on the other team and have a hot drink break. Meghan’s side of the island wasn’t as productive and she has about half the number of samples collected, which is ok, because that in itself is new information about the islands in this remote part of the world.
These islands don’t have traditional windward and leeward sides. The land-based glaciers that provide us with a surreal background for our field work are causing harsh winds to push down the sides of the ice and across us. On the opposite side, the island deals with currents and tidal action from the Amundsen Sea. It’s rough, and so is my instant latte. We forgot stir sticks and all my powder is at the bottom of the cup. I gulp it down anyway so that I can put my gloves back on and get back to work. My romanticized notion of touching Antarctica has quickly morphed into reality: Antarctica is cold and desolate and I’m pretty sure it wants to kill us. We all finish, pack up our garbage, and go back to our respective beaches.
At around 9:30pm the Zodiak returns and we make our way back to our home away from home, our little bunk beds awaiting us on the ship. Our bags are successfully filled with penguin bones, seal fur, algae, and seashells. Scott and Meghan have another three days to collect their samples. I help out for two more days with similar results on other islands, but the wind is stronger, the penguin rookeries are more expansive, and Skua attacks increase. On the last day I remain on the ship. I want to help the “science”, but the previous day was bitter, and I discovered that I enjoy having feeling in my fingers! I traded out with another member of our THOR team, PhD student James Kirkham, who was just as excited as I was when stepping on the ladder the first day.
Completing island field work in Antarctica is difficult and requires a level of unwavering dedication to the cause. Scott and Meghan carried on and completed their portion of the International Thwaites Glacier Collaboration without complaint. I have a new appreciation for the GHC team’s dedication to unravel the mystery of glacier retreat in the Amundsen Sea.
We never did find a good spot to take samples using my OSL dating expertise, but we sure did try. A crew member, Joee Patterson, even made us a blacked-out tent from several tarps and some PVC pipe, just for the purpose of taking an OSL sample in complete darkness. If you’d like to know more about our continuing work at Thwaites, check out Thwaiterglacier.org or Thwaitesglacieroffshoreresearch.org.
Victoria Fitzgerald is a National Science Foundation Graduate Research Fellow and geology PhD student at the University of Alabama. She is a mother of three, Army veteran, and a first-generation college graduate. She likes science communication, rocks, and food, but not in that order. If you want to know more about her and OSL, check her out on Twitter @fitzofscience and at fitzofscience.com coming this summer!
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