Collaborative Research: Spatiotemporal Observations of the Demise of an Ice Sheet: Paleo Perspectives from Baffin Bay, West Greenland

Lead PI: Brendan T. Reilly , Lisa Tauxe, Robert G Hatfield, Maureen H Walczak, Shannon Klotsko, Anne Jennings

Unit Affiliation: Biology and Paleo Environment, Lamont-Doherty Earth Observatory (LDEO)

October 2022 - September 2025
Active
North America ; United States
Project Type: Research

DESCRIPTION: The Greenland Ice Sheet (GIS) is shrinking today in response to the warming atmosphere and ocean. The GIS holds enough freshwater to raise sea level by 7.4 meters (24 feet) if it melted completely. Thus, understanding how it responds to warming is important. This project will investigate GIS vulnerability by studying how the GIS responded to climate warming in the past. At the end of the last ice age, about 20,000 years ago, the western GIS margin extended farther into Baffin Bay, hundreds of kilometers west of its present position. By 10,000 years ago, the ice margin had largely retreated to within the current coastline. It is unclear if a warming atmosphere, a warming ocean, or some combination of the two is responsible for the retreat. Sediments studied along the West Greenland margin as part of this project will establish regional variations in the timing, magnitude, and rate of GIS retreat during the deglaciation. The relative timing of GIS changes and ocean warming, recorded in the same sediments, will improve our understanding of the behavior of large ice sheets in the past and future. The project broader impacts include support for a postdoctoral researcher, three graduate students, and undergraduate researchers. In addition, the project will support production of an outreach film based on the proposed research expedition. The project also will facilitate development of an upper-level undergraduate course focused on the deglaciation. To accomplish this goal, an oceanographic expedition will study four West Greenland trough mouth fan systems (where the GIS deposited large volumes of sediment when it extended offshore) using seafloor and sub-seafloor imaging techniques and by collecting sediment cores spanning the end of the last ice age to present. Biological, magnetic, geochemical, and physical properties from the sediment records will be used to test the primary hypothesis; that increasing ocean temperature at the base of marine terminating glaciers is a major driver of ice-sheet instability. The project will establish: 1) the timing and extent of warm Atlantic water incursion along the west Greenland margin; 2) the phasing of ice margin retreat and ocean change; and 3) the influence of regional geology, geomorphology, and ice dynamics on ice-margin retreat. Early career leadership (supported by senior mentors) is at the heart of this project with three US-based assistant professors and one post-doctoral researcher directing shipboard operations and spearheading the post-expedition science. Half of the sea-going science party will be graduate and undergraduate students. Acquisition of the first US-based sediment cores from Baffin Bay and archival of the cores and data in US facilities and databases will provide diverse high-latitude research opportunities to the NSF community, ensuring the continuing legacy of this project.

SPONSOR:

National Science Foundation

FUNDED AMOUNT:

$214,373

EXTERNAL COLLABORATORS:

UC San Diego, University of Florida, Oregon State University, UNC Wilmington, University of Colorado

WEBSITE:

https://www.nsf.gov/awardsearch/showAward?AWD_ID=2300114

PUBLICATIONS:

Reilly, Brendan T. and Stoner, Joseph S. and Ólafsdóttir, Sædís and Jennings, Anne and Hatfield, Robert and Kristjánsdóttir, Gréta Björk and Geirsdóttir, Áslaug "The Amplitude and Timescales of 0?15 ka Paleomagnetic Secular Variation in the Northern North Atlantic" Journal of Geophysical Research: Solid Earth , v.128 , 2023 https://doi.org/10.1029/2023JB026891