An Empirical Approach for Estimating Stress-Coupling Lengths for Marine-Terminating Glaciers

Frontiers in Digital Humanities

Bartholomaus, Timothy C.¹  Enderlin, Ellyn M.²  O'²  Morlighem, Mathieu³  Hamilton, Gordon S.⁴  Neel, Shad⁴ 

[1] Alaska Science Center, US Geological Survey, Anchorage, AK, USA;Climate Change Institute, University of Maine, Orono, ME, USA;Department of Geological Sciences, University of Idaho, Moscow, ID, USA;School of Earth and Climate Sciences, University of Maine, Orono, ME, USA

关键词: Marine-terminating glaciers;    Force balance;    stress-coupling;    Columbia Glacier;    Helheim Glacier;    glacier dynamics;   

DOI  :  10.3389/feart.2016.00104

学科分类：社会科学、人文和艺术（综合）

来源: Frontiers

【 摘 要 】

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.

【 授权许可】

CC BY