Global near-IR maps from Gemini-N and Keck in 2010, with a special focus on Janus Patera and Kanehekili Fluctus

Abstract We have imaged Io in the near-infrared (1–5 μm) with adaptive optics on the 10-m W.M. Keck II and the Gemini North telescopes. We have constructed global maps from the data taken in 2010. Although numerous hot spots are visible, the maps are dominated by two volcanic centers: Loki Patera and Kanehekili Fluctus. We have examined in detail the thermal emission from Janus Patera and Kanehekili Fluctus using images obtained between 2003 and 2010, and have created a timeline of volcanic activity at these locations utilizing data from a wide variety of sources. Based on our data and this timeline we find that the thermal emission from Janus Patera is relatively steady, indicative of an active lava lake. The thermal emission from Kanehekili Fluctus, however, is quite variable, and is indicative of the emplacement of extensive lava flows. In 2010, the thermal emission from this location was ∼10 times higher than ever seen before, indicative of a particularly voluminous eruption of lava.