This award is in support of the study of the interaction of Byrd Glacier with the Ross Ice Shelf, with attention focused on the lateral rift zones of the floating ice stream tongue embedded in the ice shelf. Field data will consist of ice elevations and thicknesses mapped by radar sounding and ice velocities mapped photogrammetrically. Surface strain rates will be computed from the velocity data. Finite-element modeling will investigate two aspects of rift-zone dynamics; the stress field in the rift zone for given creep and fracture rheologies and the temperature field in a flowband that begins at the East Antarctic ice divide and ends at the calving front of the Ross Ice Shelf. The significance of this research is that it will provide a physically based means for quantifying the buttressing of Byrd Glacier by the Ross Ice Shelf. The models developed will have applications, with appropriate modifications, to other ice streams entering the Ross Ice Shelf, and will be useful in understanding dynamic processes along any flowband that has sheet-flow, stream- flow, and shelf-flow components.
