Events

Speaker: Alexandra (Allie) Balter-Kennedy, Postdoctoral Scholar, Lamont-Doherty Earth Observatory

Host: Benjamin Keisling

Title: Update from the GreenDrill project: Evidence for reduced northern Greenland Ice Sheet extent during the Pleistocene from subglacial rock and sediment

Abstract: Sediment and bedrock beneath modern ice sheets archive evidence of reduced ice-sheet extent when climate conditions were favorable for deglaciation, including during the Holocene and other Pleistocene interglacials. In this talk, I will highlight ongoing work from the GreenDrill project, which is a targeted effort to recover and analyze subglacial material at strategically selected locations in northern Greenland. In 2023 and 2024, we deployed two US NSF Ice Drilling Program drills and collected a total of ~22 m of subglacial rock and sediment. I’ll focus primarily on a core collected beneath the 500-m-thick Prudhoe Dome, an ice dome in northwest Greenland, which records ice-free periods through at least the Pleistocene, including the Holocene. Ice-sheet modeling suggests that such ice-free conditions at Prudhoe Dome require, at minimum, GrIS-wide mass loss equivalent to a 0.19–0.73 m global sea-level contribution.