Geologic Publications for Mount Rainier

Energy dissipation during subglacial abrasion at Nisqually Glacier, Washington, U.S.A.

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Author(s): Richard C. Metcalf

Category: PUBLICATION
Document Type:
Publisher: Journal of Glaciology
Published Year: 1979
Volume: 23
Number: 89
Pages: 233 to 246
DOI Identifier:
ISBN Identifier:
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Abstract:
This study examines the effect of subglacial abrasion on the basal sliding of the gravitational energy balance of the dynamic, temperate Nisqually Glacier on Mount Rainier, Washington, U.S.A. Subglacial water flux is estimated as 3 x 10⁷ m³ a^-1 and suspended sediment flux as 3 x 10⁷ kg a^-1. Suspended sediment flux is assumed to represent, within an order of magnitude, the annual mass eroded by subglacial abrasion.

Subglacial erosion involves both brittle fracture and plastic deformation. Field observations of bas-relief and grooved depression striations appear to have exact counterparts in rock mechanics experiments approximating sublgacial velocities and normal stress. Boulton's (1974) abrasion model and a new attritivity model proposed herein are shown to predict subglacial abrasion-rates within the limits of natural variability of the error range of the measurements. The first crude gravitational energy balance for lower Nisqually Glacier (1.96 km²) is attempted and probably has only order-of-magnitude accuracy. The importance of subglacial abrasion in dissipating basal sliding energy at Nisqually Glacier is confirmed.

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In Text Citation:
Metcalf (1979) or (Metcalf, 1979)

References Citation:
Metcalf, R.C., 1979, Energy dissipation during subglacial abrasion at Nisqually Glacier, Washington, U.S.A.: Journal of Glaciology, Vol. 23, No. 89, pp. 233-246.