SHORT WAVELENGTH INFRARED IMAGES FOR VOLCANO MONITORING

An remotely sensed image is presented of Mount Erebus on Ross Island in Antarctica. Mount Erebus has been a site of almost continuous magmatic activity since 1972. The main image is a Landsat Thematic Mapper (TM) band 7, 5, 4 red, green, blue colour composite of an area about 15 km across. Snow appears blue and the clouds on the right hand side appear white. Within the summit crater is a region which appears red and yellow. This represents material with sufficiently high surface temperature to radiate in the short wavelength infrared part of the spectrum covered by TM bands 5 and 7. It is shown that Landsat is of limited use for regular monitoring of volcanoes because of its 16-day repeat time, processing delays and the cost of the data. However, future spaceborne remote sensing systems equipped with short wavelength infrared scanners could be invaluable for monitoring volcanic activity. Through their ability to discover precursors to major eruptions they could play a major role in hazard warning.