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Changing ICE Loads on the Earth’s Surface During the Last Glaciation Cycle

  • J. L. Fastook
  • T. J. Hughes
Chapter
Part of the NATO ASI Series book series (ASIC, volume 334)

Abstract

The last (Wisconsin-Weichselian) glaciation cycle occurred from 120,000 to 6000 years ago. We have simulated advance and retreat of ice sheets for this cycle using the map-plane solution of our time-dependent, finite-element gridpoint computer model. Two square grids (one centered on each pole) were employed, with gridpoints spaced 100 km apart. Input at each gridpoint included constants in the flow and sliding laws of ice, bed topography, fractions of bed over which sliding dominates flow, degree of glacioisostacy (isostatic equilibrium was assumed), and surface accumulation or ablation rates. Output at each gridpoint includes ice elevation, ice thickness, and ice velocity vectors.. Time steps for input and output are variable. In this experiment, snowline slope was held constant and snowline elevation was lowered sinusoidally about 1000 m over 20,000 years, held constant for 60,000 years, and raised sinusoidally over 20,000 years. Advance and retreat of ice sheets are presented in eleven time steps for North American and Eurasian Ice Sheets, and three time steps for the Antarctic Ice Sheet. Changes over time of total ice volume and ice volume contributing to sea level are computed.

Keywords

Glacial Maximum Ablation Rate Basal Shear Stress Glaciation Cycle Glacial Geology 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science+Business Media Dordrecht 1991

Authors and Affiliations

  • J. L. Fastook
    • 1
  • T. J. Hughes
    • 2
  1. 1.Department of Computer Sciences, Institute for Quaternary StudiesUSA
  2. 2.Department of Geological Sciences, Institute for Quaternary StudiesUniversity of MaineOronoUSA

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