Temperature, age and crust thickness distributions of Loki Patera on Io from Galileo NIMS data: Implications for resurfacing mechanism

A high‐spatial‐resolution, multi‐wavelength observation by the Galileo NIMS instrument has been analysed to determine the temperature and area distribution of a large portion of the ionian volcano Loki Patera. The temperatures of the cooler components from a two‐temperature fit to the data can be used to determine ages of the surface. The age of the floor along a profile across the floor of the caldera ranges from ∼10 to ∼80 days. This puts the start of the resurfacing in July/early August 2001, yielding a resurfacing rate of approximately 1 km/day, with the new lava spreading from the SW corner of the caldera in a NE direction. This rate is consistent with resurfacing by foundering of the crust on a lava lake. However, the temperature distribution may also result from the emplacement of flows. Implied crust thicknesses (derived using a lava cooling model) range from 2.6 to 0.9 m.