EPS Colloquium – Laura A. Stevens, University of Oxford

Inland advance of ice-sheet hydro-fracture not accelerated by lower-elevation lake drainages

A rapid inland advance of supraglacial lake drainage via hydro-fracture is often posed as a mechanism for destabilisation of grounded ice-sheet flow during periods of climate warming. This hypothesis is attractive: hydro-fracture events generate large, short-timescale ice-sheet flow accelerations, and inter-lake triggering of lake drainage by hydro-fracture demonstrably occurs between neighbouring lakes. However, for the hypothesis to work, ice-flow acceleration at lower elevations must be capable of initiating hydro-fracture beneath lakes at higher elevations. In this talk, I will present key observations that contradict this hypothesis, drawing on GNSS observations of ice-sheet strain rate, physics-based modelling constraints, and feature-based classifications of hydro-fracture events in remote imagery.

To be added to the EPS colloquium mailing list, please contact Caroline Carr at carolinecarr@fas.harvard.edu

Laura A. Stevens is Associate Professor of Climate and Earth Surface Processes in the Department of Earth Sciences, and a fellow of University College, at the University of Oxford. This year, Stevens is a fellow at the Radcliffe Institute for Advanced Study.

Stevens is a geophysicist whose research focuses on hydrological drivers of ice-sheet deformation. Stevens has garnered a number of awards for their scholarship, including the American Geophysical Union’s Horton Research Grant, the European Geosciences Union’s Arne Richter Award for Outstanding Early Career Scientists, and an editor’s citation for excellence in refereeing from the journal Geophysical Research Letters. Stevens completed undergraduate studies in geosciences at Wellesley College, earned a PhD in geophysics from the Massachusetts Institute of Technology–Woods Hole Oceanographic Institution Joint Program in Oceanography/Applied Ocean Science and Engineering, and held a postdoctoral fellowship at the Lamont-Doherty Earth Observatory of Columbia University before joining the Oxford faculty in 2020.