BUBBLE COALESCENCE IN ICE AS A TOOL FOR THE STUDY OF ITS DEFORMATION HISTORY.

• Main Author: Weertman,Johannes
• Other Authors: COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H
• Format: Text
• Language: English
• Published: 1968
• Subjects: Snow; Ice and Permafrost; Mechanics; (*ICE; CREEP); HISTORY; BUBBLES; GLACIERS; AIR; THICKNESS; STRAIN(MECHANICS); MATHEMATICAL ANALYSIS; THEORY; STRESSES; MEASUREMENT; DEFORMATION; Ice; Ice Shelves; permafrost
• Online Access: http://www.dtic.mil/docs/citations/AD0682723; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0682723

An analysis is made of the rate of bubble coalescence in a deforming ice mass. A total strain of at least 8 is required before appreciable coalescence occurs. The analysis has been applied to deforming ice shelves and ice sheets. No appreciable coalescence is expected in ice shelves but coalescence should occur in ice sheets (or glaciers) if the shear strain rate at the bottom surface is of the order of 0.075/yr or larger. Measurements of bubble concentration are capable of setting limits on paleo-strain rates of the present ice sheets. Bubble migration down temperature gradients presents complications to the study of bubble coalescence. (Author)