A near real-time dual-band-spatial approach to determine the source of increased radiance from closely spaced active volcanoes in coarse resolution satellite data

摘要

Bezymianny and Kliuchevskoi volcanoes (Kamchatka) present a danger as both inject ash into North Pacific air routes. Current automated monitoring algorithms do not distinguish them in real time due to their mutual proximity (10 km) and poor geolocation accuracy of Advanced Very High Resolution Radiometer (AVHRR) data. Contrasting mid- and thermal infrared volcanic radiances are influenced by (1) differences in temperature and eruptive style of Bezymianny's andesite and Kliuchevskoi's basalt and (2) different temperatures of the non-volcanic portion of pixels located over their summits, due to different elevations. Data from 571 AVHRR images show the latter is more significant. Discriminant function analysis using summit and regional band 4 pixel-integrated radiant temperatures (pirT) correctly identifies the source volcano of a thermal anomaly in 89% of cases. Weather permitting, a spatial component can be added, leading to improved accuracy. The approach used here can also be applied at other closely spaced volcanoes with substantially different summit elevations.