Measuring thermal budgets of active volcanoes by satellite remote sensing

Abstract

ACTIVE volcanoes transfer both material and heat to the Earth's surface, but their thermal budgets are more difficult to monitor than their eruption rates, or the output of volatiles. Short-wavelength infrared data from the Landsat Thematic Mapper have been used to measure temperatures1,2, and the logical next step is to measure the total radiant energy flux, Q, in order to monitor changes in thermal budgets with time, and to allow the activity of different volcanoes to be compared. Here we report Thematic Mapper measurements of Q at Lascar volcano, north Chile, for December 1984 that are consistent with the earlier suggestion1 that a lava lake was the source of the anomaly, and values for 1985–86 that are much lower, suggesting that fumarolic activity was then a more likely heat source. Our results show that satellite remote sensing may be used to monitor the activity of a volcano quantitatively, in a way not possible by conventional ground studies, and may provide a method for predicting eruptions.