Geological Survey Professional Paper 1365 Ice Volumes on Cascade Volcanoes: Mount Rainier, Mount Hood, and Mount Shasta

Cover

Abstract

Introduction

Acknowledgments

Field measurements
   Primary data reduction
   Use of measuring point migration to correct for bedrock slope
   Use of maps and photographs to infer basal topography
   Ice-surface features and their relation to the basal topography
   Isopach maps as interpretive tools

Determination of volumes
   Measured glaciers
   Unmeasured glaciers and snow patches

Results from four Cascade volcanoes
   Mount Rainier
   Mount Hood
   Three Sisters
   Mount Shasta

Conclusions

Appendix on monopulse radar
   Application

References cited

PLATES 1-6. Maps showing: (omitted from the online edition)

FIGURE

9—11. Mount Rainier graphs showing:

13—15. Mount Hood graphs showing:

17—19. Three Sisters graphs showing:

21—23. Mount Shasta graphs showing:

24—27. Diagrams showing:

2—5. Areas and volumes of glacier ice and snow on:

Aerial photograph of Collier Cone, Oreg. (bottom-center of photograph), a cinder cone similar in eruption characteristics to the Mexican volcano Paricutin. Active between 500 and 2,500 years B.P. (Taylor, 1981, p. 61), the cone erupted between the lateral moraines of Collier Glacier. During the early 1930's, the terminus of Collier Glacier abutted the south flank of Collier Cone, reworking the cinders into the striated pattern visible today (Ruth Keen, Mazamas Mountaineering Club, oral commun., 1984). Williams (1944) reported the presence of glacial moraine interspersed with lava flows around the base of Collier Cone. (U.S. Geological Survey photograph by Austin Post on September 9, 1979.)

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DEPARTMENT OF THE INTERIOR
DONAL PAUL HODEL, Secretary

U.S. GEOLOGICAL SURVEY
Dallas L. Peck, Director

Library of Congress Cataloging-in-Publication Data
Driedger, C. L. (Carolyn L.)
Ice volumes on Cascade volcanoes.

Supt. of Docs. no: I 19.16:1365
1. Glaciers—Cascade Range—Measurement. 2. Snow—Cascade Range—Measurement. 3. Volcanoes—Cascade Range. 4. Flood forecasting—Cascade Range. I. Kennard, P. M. (Paul M.) II. Title.
GB2420.D75 1985 551.3'1'09795 84-600381

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Symbol	Name
A	Surface area
b	Slope of bedrock measured from horizontal
c	Speed of light in ice
c0	Speed of light in a vacuum
CI	Contour interval
d	Transmitter-receiver separation distance
g	Gravitational acceleration
h	Thickness measured perpendicular to the reflecting point on a glacier bed
h'	Vertical distance between the measurement point and the bedrock
i	(Subscript) indicates an interval value
k1,2,3	Coefficients derived from regression analysis
l	Glacier length
p	Path of light
R	Resistance per unit length
t	Time between arrivals of air and reflected waves on the oscilloscope
V	Volume
V*	Volume estimation by calculation of basal shear stress
x	Distance from antenna feedpoint in meters
α	Slope of ice measured from horizontal
	Antenna half-length (meters)
η	Refractive index of ice
υ	Frequency
ρ	Density of ice
τ	Basal shear stress
τ*	Estimated basal shear stress
ψ	Resistive loading constant (ohms)

For readers who prefer International System (SI) units, conversion factors for terms used in this report are listed below. Except where required by use with maps, stresses are expressed in bars (105 Pascals), a preferred unit in glaciology.

Water equivalence:

In this study, inch-pound units have been used to be compatible with the most current U.S. Geological Survey topographic maps.