An empirical approach for estimating stress-coupling lengths for marine-terminating glaciers

Frontiers in Earth Science
By: , and 

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Abstract

Variability in the dynamic behavior of marine-terminating glaciers is poorly understood, despite an increase in the abundance and resolution of observations. When paired with ice thicknesses, surface velocities can be used to quantify the dynamic redistribution of stresses in response to environmental perturbations through computation of the glacier force balance. However, because the force balance is not purely local, force balance calculations must be performed at the spatial scale over which stresses are transferred within glacier ice, or the stress-coupling length (SCL). Here we present a new empirical method to estimate the SCL for marine-terminating glaciers using high-resolution observations. We use the empirically-determined periodicity in resistive stress oscillations as a proxy for the SCL. Application of our empirical method to two well-studied tidewater glaciers (Helheim Glacier, SE Greenland, and Columbia Glacier, Alaska, USA) demonstrates that SCL estimates obtained using this approach are consistent with theory (i.e., can be parameterized as a function of the ice thickness) and with prior, independent SCL estimates. In order to accurately resolve stress variations, we suggest that similar empirical stress-coupling parameterizations be employed in future analyses of glacier dynamics.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title An empirical approach for estimating stress-coupling lengths for marine-terminating glaciers
Series title Frontiers in Earth Science
DOI 10.3389/feart.2016.00104
Volume 4
Year Published 2016
Language English
Publisher Frontiers Media S.A.
Contributing office(s) Alaska Science Center
Description 12 p.
First page 1
Last page 12