Environmental Science and Engineering Seminar
Among the many challenges of constraining how Antarctica is responding to climate change is one that is inherent to the problem itself: it's hard to get to the bottom of all that ice. Beneath tens to hundreds to thousands of meters of ice lie the interfaces that define the boundary conditions of the cryosphere. Over the past thirty years, hot water drilling has enabled access to some of these regions and peeled back the ice cover to better understand the ocean and sediments below it. But only recently has the most dynamic part of the system become accessible--by drilling near grounding zones where the ice, ocean, and bed meet. For the past ten years, our team has developed the Icefin vehicle by focusing on what to do when we get there. Icefin is a novel, modular and (relatively) low logistics underwater vehicle outfitted to split the gap between large open ocean autonomous vehicles and small "roving eye" vehicles. Carrying a comprehensive suite of oceanographic sensors as well as cameras and sonars to perceive, explore and map the ice, ocean and seafloor has given us new eyes to understand ice-ocean-bed interactions.We have now had the chance to observe four different grounding zone or near-grounding zone environments of Antarctic ice shelves and glaciers with Icefin. These regimes span from large to small, from warm- to cold-based, and open ocean to channelized systems. In each environment, we have been able to resolve key details of the sub-ice dynamics that have been unobservable by other means. In this presentation, I will share examples from Thwaites Glacier (large, warm-based), Kamb Ice Stream (large, cold-based, open and channelized) and Fimbulisen (large, mid-range) including comparisons of ice and seafloor morphology and crevasse environments. Excitingly, comparisons of the ice-ocean interactions across these regimes shows promise towards refining how we understand the driving processes across diverse ocean forcing. With any luck, these new observations will help improve forecasts of future change, and motivate new voyages of discovery on Earth and beyond.