Collaborative Research: Ice-Shelf Rumpling and its Influence on Ice-Shelf Buttressing Processes.

Non-Technical Abstract: This project explores the areas or crash-zones where floating ice shelves in Antarctica compressively flow against obstructions such as islands and plugs of stagnant ice frozen to the sea bed. The significance of these crash-zones is that they are responsible for generating the resistive forces that allow ice shelves to slow down the flow of ice farther inland into the ocean. Ice conditions within these boundaries thus determine how Antarctica’s ice sheets contribute to sea-level rise. The research will feature on-the-ice glaciological and geophysical field measurements near pressure ridges near Scott Base and the transition to the ice road where large wave-like pressure ridges form on the ice-shelf surface. This field area is along the coast of Ross Island adjacent to major logistical stations of the US and New Zealand Antarctic programs. Thus the research will help station managers better preserve one of the key roadways that connects the stations to the major runway used to fly to virtually all other parts of Antarctica. The research will also interact with educational programs such as featured in the long-standing Juneau Icefield Research Project as well as potential involvement of an artist from the US Antarctic Program’s Polar STEAM in the second field season. Technical Abstract: This project explores the dynamics of boundaries where ice shelves compressively flow against obstructions such as islands and areas of grounded ice. The significance of these boundaries is that they are responsible for generating the resistive forces that allow ice shelves to impede or slow down the flow of grounded inland ice into the ocean. Ice conditions within these boundaries thus determine how Antarctica’s ice sheets contribute to sea-level rise. The research will feature glaciological and geophysical field surveys in a compressive boundary area near pressure ridges adjacent to Scott Base and the transition to the ice road along the coast of Ross Island, an area affecting access to major logistical hubs of the US and New Zealand Antarctic programs. Field data will be combined with remote sensing, numerical modeling and theory development to answer key questions about the dynamics of compressive boundaries such as: is there a limit to compressive stress due to ice fracture and the bending of the ice shelf into sinusoidal pressure ridges? Over what time scales does this compressive stress build, fluctuate and decay, and how is it related to the processes that form rumples? Are there ways in which the ridges actually protect the compressive boundary from damage such as by setting up a means to scatter ocean swell impinging from the open ocean? How should compressive ice-shelf boundaries be represented in large scale ice-sheet/shelf models for the prediction of future sea-level rise? A variety of broader impact work will be done both specifically targeting the research field area and more broadly addressing scientific and societal concerns. The field area contains a critical logistics roadway that connects McMurdo Station, Scott Base and a runway essential for continent-wide air logistics. The project will inform how to stabilize the roadway against excessive damage from summer ablation and other factors. Other broader impacts include: (a) Open-Science evaluation of climate systems engineering strategies for glacial geoengineering mitigation of sea-level rise, (b) cooperation with the Juneau Icefield Research Program (JIRP) education component, (c) support and facilitation of an online FieldSafe workshop and associated panel discussion to support early-career Antarctic field teams to mitigate environmental and interpersonal risks in remote field sites, and (d) potential involvement of an artist from the US Antarctic Program’s Polar STEAM in the second field season. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.