EarthRef.org Reference Database (ERR)
Development and Maintenance by the EarthRef.org Database Team

Detailed Reference Information
Ackley & Keliher 1979
Ackley, S.F. and Keliher, T.E. (1979). Ice sheet internal radio-echo reflections and associated physical property changes with depth. Journal of Geophysical Research 84: doi: 10.1029/JB080i010p05675. issn: 0148-0227.

The use of radio-echo sounding records to indicate the presence of internal layers within large ice sheets is of interest to glaciologists because it offers a possible means of tracking the internal properties of the ice sheets over large distances. In this paper we use the measured physical properties of core to bedrock taken at Cape Folger, East Antarctica (66¿22'S, 111¿E, 324-m depth), to compute a depth-reflection coefficient profile for comparison with the observed radio-echo reflections. The measurements available on physical properties are density variations, bubble size and shape changes, and crystal fabric variations. In calculations to differentiate the effects of the physical properties, it appears that density variations account for the primary contributions to the calculated dielectric property changes corresponding to the highest observed reflection coefficients. However, bubble changes alone can also account for reasonable, though lower, reflection coefficients at the depths corresponding to observed reflections. Crystal fabric variations correspond poorly with the reflection locations. The close correspondence between the depths of the bubble shape changes (which are definitely deformational features) and the depths of the density variations, and between both of these and the radio-echo layers, indicates that deformational events in the ice sheet's history are represented by the variations in physical properties and associated radio-echo records.

BACKGROUND DATA FILES

Abstract

Journal
Journal of Geophysical Research
http://www.agu.org/journals/jb/
Publisher
American Geophysical Union
2000 Florida Avenue N.W.
Washington, D.C. 20009-1277
USA
1-202-462-6900
1-202-328-0566
service@agu.org
Click to clear formClick to return to previous pageClick to submit