Wave field migration as a tool for estimating spatially continuous radar velocity and water content in glaciers

John Bradford, Boise State University
Joel T. Harper, University of Montana - Missoula

An edited version of this paper was published by AGU. Copyright (2005) American Geophysical Union.


Normal-moveout velocity analysis can lead to significant overestimates of the velocity structure of temperate glaciers since most englacial reflectors approximate point scatters and violate the assumption of planar flat lying reflectors. Migration velocity analysis (MVA) is a tool that does not depend on the assumption of flat lying reflectors. MVA can provide laterally and vertically continuous velocity estimates from conventional common-offset radar sections. In a study of temperate Bench Glacier, Alaska, we used MVA coupled with dielectric modeling to estimate the distribution of water content along a cross-section of the glacier. We found the glacier has two layers, an upper layer with relatively low water content, and lower layer with relatively high water content. The ability to quantify hydrostratigraphy is important in understanding water storage and routing within glaciers.