Volcanic hot spots on Io: correlation with low- albedo calderas.

Comparison of Voyager imaging data with Voyager 1 infrared observations (IRIS) and with ground-based telescopic infrared data demonstrates a strong correlation between hot spots and low-albedo features (reflectivity = or <0.3 in all visual wavelengths) on Io. Most of these low-albedo areas occur on the floors of volcanic calderas, and many are associated with active or recent volcanism. We use this correlation to identify additional hot spots in regions not observed by IRIS and to model their temperatures. Our model temperature for the S-polar feature is 280+ or -50 K. Taking account of the high latitudes of these features, the estimated global average heat flow from the hot spots becomes 1.8+ or -0.5 W m^-2.-from Authors