Call number:
ZSP-202-115
In:
Research report / Cold Regions Research and Engineering Laboratory, 115
Description / Table of Contents:
SUMMARY Between 1 July and 7 August 1960, the U.S. Army Snow Ice and Permafrost Research Establishment, Corps of Engineers, supported a £our-man glaciological expedition on the southern dome of the Greenland ice sheet. Measurements of snow temperature, density, ram hardness, and grain size were made at seven pit ~tudies along 191 mileS of over-snow traverse. In addition to the pit studies, 38 Rammsonde profiles were measured and 166 shallow pits were dug to measure temperature in the first meter of snow. The annual accumulation of snow was found to decrease westward, from 97 em water equivalent 50 miles from tP.e east coast, to 40 em 80 miles from the western margin. A possible precipitation shadow was encountered immediately west of the crest line of the ice sheet. The precipitation shadow and the decrease in accumulation westward indicate that the source area for the precipitation lies to the east of the southern dome, in the. Greenland Sea. Temperature profiles in the firn indicated that summer warming was still in progress. During August, melting at an elevation of 2000 m above se~ level was intense (OC in the top 75 em} •. According to the facies classification of glaciers (Benson, 1959, 1960}, most of the study area is in tfie percolation facies, with the possible exception of the westernmost· s.tation (mile l-138) which is at or near the saturation line. The daily heat exchange in the first meter of snow, near the time of maximum melt conditions, is between 20 and '35 cal/cinZ. This is approxi-mately 25o/o of the heat necessary to raise the temperature of a column of firn of unit cross Section and 1 m deep to the melting point. Effective values of thermal conductivity and diffusivity as determined from the temperature curves with no attempt made to isolate radiation and con-vection are, respectively, 4-6 x 10-3 cgs and 20-30 x 10-3 cgs. Radiation and convection in the first meter of firn cause "effective conductivity" values to be 4 to 7 times greater than the value k = 0. 0068pZ given by Abel's (1892), which is the conductivity at greater depths.
Type of Medium:
Series available for loan
Pages:
v, 22, A4, B1 Seiten
,
Illustrationen
Series Statement:
Research report / Cold Regions Research and Engineering Laboratory 115
URL:
https://erdc-library.erdc.dren.mil/jspui/bitstream/11681/5839/1/CRREL-Research-Report-115.pdf
Language:
English
Note:
CONTENTS
Preface
Summary
Introduction
Method of investigation
Location
Pit studies
Temperature
Hardness
Density
Stratigraphic measurements
Thermal studies
Stratigraphic features
Grain size
Grain shape
Crusts
Discussion of results
Temperature
Altitude gradient
Latitude gradient
Depth-density relationship
Depth-load relationship
Densification
Stratigraphic analysis
Facies relationship
Climatological aspects
1960 meteorological observations
Temperature
Wind
Barometric pressure
Radiation
Cloudiness
Visibility
Thermal studies
Summary and conclusions
References
Appendix A
Appendix B
Location:
AWI Archive
Branch Library:
AWI Library
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