EAS Seminar Series -- Christine McCarthy

Description

Viewing glacier motion through the lens of stick-slip fault mechanics

Christine McCarthy
Research Scientist
Columbia’s Lamont Doherty Earth Observatory

Abstract

Ice streams represent a significant portion of the Antarctic ice mass balance. Understanding the controls on flow and sliding rates are key to predictive modeling of sea level rise. In my laboratory experiments I measure the frictional properties that control basal sliding. In particular, I will present results from ice-on-rock friction experiments in which the driving velocity was periodic, representing tidal modulation. Using the formulation of rate- and state- dependent friction that has been used to describe earthquakes and fault dynamics for decades and the parameters gleaned from the experiments, we are able to describe the full range of sliding behavior (from creeping to modulation to episodic stick-slip) observed both in the lab and in nature.

Biography

Christine McCarthy is a research scientist at Columbia’s Lamont Doherty Earth Observatory. She received her Masters and Ph.D. from Brown University, after which she conducted a two-year postdoc fellowship in Tokyo at the Earthquake Research Institute. She specializes in running laboratory experiments that measure how ice and other geologic materials respond to external forcing at various timescales, such as how glaciers slide or how seismic waves are damped as they travel through the Earth. In particular she is interested in how features at the microscopic scale affect macroscopic-scale behavior. Recent projects have expanded her research into carbon mineralization and technology testing for outer solar system mission design. She runs a large and vibrant team in the Rock and Ice Mechanics Lab.