MAPPING SUBGLACIAL SURFACES OF TEMPERATE VALLEY GLACIERS BY 2-PASS MIGRATION OF A RADIO-ECHO SOUNDING SURVEY

High-resolution maps of the glacier bed are developed through a pseudo -three-dimensional migration of a dense array of radio-echo sounding p rofiles. Resolution of three-dimensional maps of subglacial surfaces i s deter mined by the radio-echo sounding wavelength, data spacing in t he field, and migration. Based on synthetic radio-echo sounding profil e experiments, the maximum resolution of the final map cannot exceed o ne half-wavelength, A methodology of field and processing techniques i s outlined to develop a maximum-resolution map of the glacier bed. The field and processing techniques are used to develop a map of the glac ier bed below part of Worthington Glacier, a temperate valley glacier in south-central Alaska. The field techniques and the processing steps used on the glacier result in a map of 20 m x 20 m resolution.