A Seven Decade History of Flow at Saskatchewan Glacier

Nathan Stevens

Abstract: Glacier dynamics respond to climate cycles that operate on timescales of decades to megaannum, but direct observations of these dynamics are limited to the last two centuries. Glacier flow is the sum of internal deformation and slip of the glacier over its bed, which respond in different ways to external forcing from climate. Wide scale observations of glacier flow are limited to the past 5 decades from satellite imaging, but even these are subject to constraints of instrument resolution and the distribution of ground-truth data. Temporal, geographic, and resolution constraints put a premium on connecting observational studies prior to the satellite-era to modern observation. One such study site is Saskatchewan Glacier, in Banff National Park of Canada, which had extensive observation of its dynamics collected in 1952-1954. Subsequent studies of its geometry and flow are scattered through time, and largely leverage space-borne observations. In 2017 and 2019 we collected extensive on-ice observations of the geometry, flow dynamics, and hydrology of Saskatchewan Glacier, providing a bridge between vintage observations and modern data sets. We construct a 7-decade history of the flow dynamics of this mountain glacier under the influence of short-period climate cycles and anthropogenic forcing. This record demonstrates that basal sliding has become the prominent, and perhaps perennial, process of glacier flow near the toe of Saskatchewan Glacier in the past two decades. Our findings highlight the importance of rising melt water availability on glacier dynamics.

Time: April 22nd (12:00)

Advisor: Luke Zoet

Co-Authors: C.J. Roland, L.K. Zoet, R.B. Alley, D.D. Hansen, E. Schwans

Stream: Zoom

Email: ntstevens@wisc.edu