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






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


Appendix on monopulse radar

References cited


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

1. Basal and surface contours of radar-measured glaciers on Mount Rainier, Washington.
2. Isopachs of radar-measured glaciers on Mount Rainier, Washington.
3. Basal and surface contours of radar-measured glaciers on Mount Hood, Oregon.
4. Basal and surface contours of radar-measured glaciers on Three Sisters, Oregon.
5. Isopachs of radar-measured glaciers on Three Sisters and Mount Hood, Oregon.
6. Basal and surface contours of radar-measured glaciers on Mount Shasta, California, and Whitney Glacier isopachs.


1. Index map showing locations of volcanoes in study areas
2. Photograph showing ice radar equipment used during study
3. Scheme of interactive processes to produce basal maps
4. Diagrams showing (A) location of transmitter and receiver and (B) slope correction necessary for measuring vertical ice thickness
5. Photographs of (A) Nisqually Glacier, 1944, and (B) Nisqually Glacier, 1980
6. Rock avalanche debris concealing glacier ice on Lost Creek Glacier, South Sister, Oregon
7. Diagram of a volume element
8. Photograph of Mount Rainier, Washington

9—11. Mount Rainier graphs showing:

9. Ice and snow area by altitude
10. Ice volume by altitude on glaciers measured with ice radar
11. Ice area by thickness
12. Photograph of Mount Hood, Oregon

13—15. Mount Hood graphs showing:

13. Ice and snow area by altitude
14. Ice volume by altitude on glaciers measured with ice radar
15. Ice area by thickness
16. Photograph of the Three Sisters, Oregon

17—19. Three Sisters graphs showing:

17. Ice and snow area by altitude
18. Ice volume by altitude on glaciers measured with ice radar
19. Ice area by thickness
20. Photograph of Mount Shasta, California

21—23. Mount Shasta graphs showing:

21. Ice and snow area by altitude
22. Ice volume by altitude on glaciers measured with ice radar
23. Ice area by thickness on Whitney Glacier

24—27. Diagrams showing:

24. Schematic of radar system
25. Antenna detail
26. Oscilloscope output
27. Typical antenna configurations

1. Glacier lengths, mean basal shear stresses, and volume estimation applications

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

2. Mount Rainier
3. Mount Hood
4. Three Sisters
5. Mount Shasta
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.)


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

ASurface area
bSlope of bedrock measured from horizontal
cSpeed of light in ice
c0Speed of light in a vacuum
CIContour interval
dTransmitter-receiver separation distance
gGravitational acceleration
hThickness 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
k1,2,3Coefficients derived from regression analysis
lGlacier length
pPath of light
RResistance per unit length
tTime between arrivals of air and reflected waves on the oscilloscope
V*Volume estimation by calculation of basal shear stress
xDistance from antenna feedpoint in meters
αSlope of ice measured from horizontal
Antenna half-length (meters)
ηRefractive index of ice
ρDensity of ice
τBasal shear stress
τ*Estimated basal shear stress
ψResistive 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.

Multiply inch-pound unitByTo obtain SI unit

foot (ft)0.3048meter (m)
square foot (ft2)0.0929square meter (m2)
cubic foot (ft3)0.0283cubic meter (m3)
mile (mi)1.609kilometer (km)
square mile (mi2)2.590square kilometer (km2)
cubic mile (mi3)4.168cubic kilometer (km3)
pounds per square foot (lb/ft2)4.787 x 104bar
slugs per cubic foot (slug/ft3)1.187kilogram per cubic meter (kg/m3)

Water equivalence:

Volume of water in cubic feet = Volume of ice in cubic feet (1.8 slugs/ft3)
1.94 slugs/ft3

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

<<< Previous <<< Contents >>> Next >>>

Last Updated: 28-Mar-2006