Use of SEASAT Synthetic Aperture Radar and LANDSAT Multispectral Scanner subsystem data for Alaskan glaciology studies

Abstract

SEASAT synthetic aperture radar (SAR) and LANDSAT multispectral scanner subsystem (MSS) data of three areas in Alaska were studied in order to determine what hydrological information could be extracted using digital data from both sensors. The first area is located in northern Alaska and contains numerous thaw lakes. The other areas contain valley glaciers in the Alaska Range and a piedmont glacier (Malaspina), in south central and southern Alaska, respectively. SAR and MSS subscenes of the thaw lakes and subscenes of the Malaspina Glacier were digitally registered. Registration of the data in the Alaska Range study area was not feasible due to a lack of sufficient tie points resulting from shadowing and layover effects in the SAR data. Results of the data obtained from the thaw lake study area showed that the location and identification of some older remnant lake basins were more easily determined in the registered data using an MSS/SAR overlay than in either SAR or MSS data alone. Separately, both the SAR and the MSS data were useful for determination of surging glaciers based on their distinctive medial moraines, and LANDSAT data were useful for locating the glacier firn zone. In the analysis of the Malaspina Glacier scenes, the SAR data were useful for locating heavily crevassed ice beneath glacial debris, and LANDSAT provided information concerning the extent of the debris overlying the glacier. Together, the data set gave a good representation of the extent of the glacier and crevasse patterns.