PAOC Colloquium: Brent Minchew (MIT)

Monday, May 14, 2018 - 12:00

Title: Marine ice sheet dynamics

Abstract: Marine ice sheets are continental-scale masses of glacier ice that rest on beds that lie below sea level. Because ice floats, this configuration is susceptible to a buoyancy-driven instability, known as the marine ice sheet instability, that can lead to rapid discharge of grounded ice to the ocean and high rates of sea level rise. This potential for collapse makes the West Antarctic Ice Sheet—the only extant marine ice sheet—the largest source of uncertainty in future sea level rise and a key player in abrupt changes in past sea level. Constraining the past and forecasting the future behavior of marine ice sheets is challenging because of the complex rheology of glacier ice and interactions between the ice sheets, oceans, atmosphere, and the solid earth. These factors help drive rich dynamical behavior that has only recently been brought into greater focus through improved observations and an increasingly sophisticated understanding of glacier mechanics. In this talk, I will give a broad introduction to marine ice sheet dynamics followed by a more focused discussion on the mechanics of lateral shear margins and ice-shelf buttressing, two of the most important resistances to ice flow that have the potential to reshape our understanding of marine ice sheet behavior and sea level rise.

About the Speaker

Brent Minchew is a geophysicist working to understand the interactions between climate, the cryosphere, and the solid Earth. He uses a combination of geodetic observations—primarily interferometric synthetic aperture radar (InSAR)—and physical models to study dynamical systems and their various responses to environmental forcing.

The bulk of Minchew’s research focuses on the dynamics of extant glaciers, with an emphasis on the mechanics of glacier beds, ice-ocean interactions, and ice rheology. By modulating ice flow and directly influencing glacier erosion rates, these factors play critical roles in glacier and ice sheet evolution, the dynamic response of glaciers to climate change, and the impact of glaciers on landform evolution and the global carbon cycle over human to geological timescales.

Minchew’s preferred approach to understanding complex systems is to focus on short-timescale (hourly to sub-decadal) variations in the dynamics of large-scale systems in response to known forcings. Examples of this work include spatiotemporal observations and models of the dynamic response of glaciers to surface meltwater flux, ocean tidal forcing, and ice shelf thinning.

About this Series

The PAOC Colloquium is a weekly interdisciplinary seminar series that brings together the whole PAOC community. Seminar topics include all research concerning the physics, chemistry, and biology of the atmospheres, oceans and climate, but also talks about e.g. societal impacts of climatic processes. The seminars generally take place on Monday from 12-1pm. Lunch is provided to encourage students and post-docs to meet with the speaker. Besides the seminar and lunch, individual meetings with professors, post-docs, and students are arranged.

Presented by

Brent Minchew, Assistant Professor, MIT Department of Earth, Atmospheric and Planetary Sciences
Location: 54-915