Event

The Department of Earth & Environmental Science

University of Pennsylvania

Invites you to attend a EES Seminar Series

Friday, September 1st - 3:00 PM

"Understanding Greenland Outlet Glacier Calving Using Big Data"

With the advent of multiple satellite sensors pointed at the poles we are amid a data explosion that assist in examining ice sheet changes. This is particularly true for the ice-ocean boundary, which represents one of the most changeable parts of the Greenland Ice Sheet. Outlet glaciers lose mass, in part, through the physical breaking of ice, or calving, with at least two different styles of calving identified in the literature; 1) buoyant flexure where basal crevasse propagation through the glacier releases full-thickness tabular icebergs and 2) sloughing of ice likely related to undercutting from submarine melt of the glacier terminus. While these physical mechanisms have been identified, there is no parameterization for calving that represents both styles adequately. In an effort to improve calving representation in ice sheet models we present a new dataset of glacier termini derived from machine learning and novel analyses of these data to understand calving style. AutoTerm is a collection of nearly 300,000 glacier terminus delineations from 295 glaciers in Greenland extending back to 1985 produced through a semi-automated deep learning pipeline. AutoTerm provides increased temporal resolution in terminus data over prior datasets allowing for unprecedented detail in glacier calving, particularly after 2014. We use AutoTerm data to examine glacier calving style for a subset of glaciers using two independent methods – one that examines the terminus shape and one that makes use of terminus change over time. These methods are validated with detailed observations. We argue that these simple categorizations of calving style will assist with the development of and/or assignment of a particular existing calving parameterizations in ice sheet models.

Dr. Ginny Catania

Professor in the Department of Geological Sciences

Senior Scientist appointment at the Institute for Geophysics

Jackson School of Geosciences at the University of Texas

Dr. Ginny Catania is a Professor in the Department of Geological Sciences and a Senior Scientist at the Institute for Geophysics. Both units are located within the Jackson School of Geosciences at the University of Texas. Catania’s research centers on understanding the physics that govern ice sheets at their boundaries, primarily the ice-ocean and ice-bed interface. She has led over a dozen expeditions to Greenland and Antarctica to study these inaccessible parts of the ice sheets and her efforts have resulted in over 60 peer-reviewed publications. Her research approach relies heavily on the use of observations from both in-situ and remotely-sensed data. Catania also dedicates her time to improving the sense of inclusion in academia through professional and personal development of staff, faculty, researchers, and students via the Geoscience Empowerment Network at UT-Austin. Dr. Catania holds a PhD in Geophysics from the University of Washington (2004) and a MS in Geology from the University of Minnesota (1998). She hails from Canada and sometimes wonders how she ended up in a state that has never been glaciated. More information on her work is available at www.catania-ice.org and genatjsg.org.