loading page

Seismic Evidence of Impact Breccia and Unlithified Sediments under Hiawatha Glacier
  • +5
  • Rishi Chandra,
  • Kiya Riverman,
  • Daniella N DellaGiustina,
  • Erin Christine Pettit,
  • Nicholas Charles Schmerr,
  • Georgia Carroll,
  • Veronica J. Bray,
  • Samuel H. Bailey
Rishi Chandra
The University of Arizona Department of Planetary Sciences and Lunar and Planetary Laboratory

Corresponding Author:[email protected]

Author Profile
Kiya Riverman
Department of Environmental Studies, University of Portland
Author Profile
Daniella N DellaGiustina
Lunar & Planetary Laboratory, University of Arizona
Author Profile
Erin Christine Pettit
Oregon State University
Author Profile
Nicholas Charles Schmerr
University of Maryland, College Park
Author Profile
Georgia Carroll
Oregon State University
Author Profile
Veronica J. Bray
University of Arizona
Author Profile
Samuel H. Bailey
University of Arizona
Author Profile

Abstract

Hiawatha Crater in northwest Greenland is one of only two confirmed impact craters under an ice sheet. Hiawatha therefore offers a rare proxy for understanding the interactions between active glacial dynamics and impact craters on other planetary bodies. Here we characterize Hiawatha’s subglacial environment, presenting the results of two active-source seismic experiments and interpreting them in concert with previous radar sounding analysis. Seismic reflectivities at a site with a single basal radar reflector are consistent with a substrate of impact melt-bearing breccia. At a site where radar sounding revealed a porewater reflector 10–15 m below the base of the ice sheet, our seismic results are consistent with a substrate of unlithified sediments. We propose a model where supraglacial water supplies heat for basal melting, leading to rain–out of unconsolidated sediment from dirty basal ice (fringe) and permitting a permeable porewater-bearing basal layer to persist without consolidating.
04 Sep 2024Submitted to ESS Open Archive
05 Sep 2024Published in ESS Open Archive