This award will support a combined airborne radar and aeromagnetic survey of two 220 x 330 km regions between the Transantarctica Mountains and Marie Byrd Land during the 1990-91 and 1991-92 field seasons. These efforts will address significant problems identified in the Ross Transect Zone (RTZ) by the National Academy of Sciences (1986) report "Antarctic Solid Earth Sciences Research," and by the report to NSF "A Plan for a United States Program to Study the Structure and Evolution of the Antarctic Lithosphere (SEAL)." The surveys will be flown using the NSF/TUD radar and an areomagnetics system mounted in a light aircraft. The grid spacing will be 5 km and navigation will be by radiopositioning. In addition to maps of subglacial topography and magnetic intensity, attempts will be made to reconstruct the position of subglacial diffractors in three dimensions. This reconstruction should give new information about the distribution of escarpments and therefore the tectonic relationships within the region, especially when combined with the magnetic results. These experiments will be conducted by the Byrd Polar Research Center of the Ohio State University and the Water Resources and Geological Divisions of the U.S. Geological Survey.
