Volcanic Eruptions on Io: Heat Flow, Resurfacing, and Lava Composition

Abstract

In this paper we consider the infrared outbursts on Io reported over the last 15 years and examine the implications for resurfacing rates and heat flow using a recent, well observed, eruption sequence. A large change was observed in Io's infrared emission on January 9, 1990 at several different wavelengths. We model this event as due to a large actively erupting lava flow. The flow increased its area at a rate of 1.5 x 10⁵ m²s^-1 and cooled from 1225 K to 555 K over about 2.6 hours. This event is consistent with other Io infrared outbursts and is used in this paper to estimate the more general characteristics of Ionian volcanism, resurfacing, and heat flow. The inferred eruption rate of 3 x 10⁵m³s^-1 is very high, but is not unprecedented on the Earth.