Author ORCID Identifier

https://orcid.org/0009-0002-2329-0701

Date of Award

Spring 5-5-2026

Document Type

Thesis (Ph.D.)

Department or Program

Earth Sciences

First Advisor

Mathieu Morlighem

Second Advisor

Meredith Kelly

Abstract

Glacier margins encode and imprint signals of climate, topography, erosion, and ice dynamics, but interpreting those signals requires disentangling the contributions of multiple interacting processes. This dissertation develops ensemble numerical modeling and large-scale data-driven approaches to investigate dynamical imprints on ice extent and bedrock erosion across diverse glaciological settings. An evaluation of four calving laws for Antarctic ice shelves with the Ice-sheet and Sea-level System Model identifies which calving laws best capture the observed steady-state calving front on a shelf-by-shelf basis, with practical consequences for ice sheet modelers and sea-level rise projections. A coupled energy-balance–ice-flow model applied to tropical alpine Colombia shows that topography exerts a non-negligible influence on glacier extent in the context of climatic forcing, with implications for how moraine-based paleoclimate reconstructions should be interpreted. A large ensemble of glacier simulations at Páramo de Frontino, Colombia, constrained by moraine extent, implies that lapse rate steepening was a pan-tropical phenomenon during the Last Glacial Maximum. Finally, a large-scale remote-sensing framework links NASA ITS_LIVE glacier surface velocities to Sentinel-2-derived proglacial suspended sediment concentration across more than a thousand glacier-river systems. Within individual glaciers, a canonical velocity–erosion scaling relationship emerges during velocity pulse events for some regions; for the baseline velocity state, this scaling relationship frequently disappears. Together, these results provide quantitative constraints on how ice dynamics, climate, and erosion operate at glacial boundaries across a range of settings, scales, and methods, and demonstrate that systematic ensemble approaches, whether across a model parameter space or across satellite observations, are a productive means of resolving the ambiguity inherent in signals preserved at the ice margin.

Original Citation

Wilner, J. A., Morlighem, M., & Cheng, G. (2023). Evaluation of four calving laws for Antarctic ice shelves. The Cryosphere, 17(11), 4889-4901.

Wilner, J. A., Doughty, A. M., Kelly, M. A., & Morlighem, M. (2025). Disentangling topographic and climatic controls on glacier length: A case study in the tropical Colombian Andes. Earth and Planetary Science Letters, 667, 119511.

Available for download on Thursday, May 20, 2027

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