It was not a good time to be sitting on Io last August. Scientists observed three massive volcanoes erupting over a two-week period. Two studies were commissioned on the event, and it turns out that eruptions may be more common than scientists first realized.
Io is the third largest of Jupiter’s four large moons, and is the only other location in our solar system that spews lava. If that’s not enough, Io’s low gravity coupled with Jupiter’s gravitational pull is strong enough to push debris from the explosions high into space.
Both studies are to be published in the journal, Icarus. They each cover the volcanic eruptions and the frequency. Imke de Pater, professor and chair of astronomy at UC Berkeley talked about the findings. “We typically expect one huge outburst every one or two years, and they’re usually not this bright,” said Imke de Pater, professor and chair of astronomy at the University of California, Berkeley. “Here we had three extremely bright outbursts, which suggest that if we looked more frequently we might see many more of them on Io.”
The first two eruptions were discovered by de Pater on August 15, 2013. Both occurred in Io’s southern hemisphere. Using the NIRC2, a near-infrared camera and Keck II telescope, scientists were able to image both eruptions. The brighter of the two eruptions took place at the Rarog Patera caldera. Researchers calculated it produced a 50-square-mile, 30-feet-thick lava flow. The eruption at the Heno Patera caldera produced a flow that covered 120 square miles.
A third eruption was seen on August 29, 2013 and was the brightest. Two different telescopes caught this event – the Gemini North telescope on Mauna Kea, and NASA’s nearby Infrared Telescope Facility (IRFT).
Ashley Davis, a volcanologist from NASA’s Jet Propulsion Lab commented on the latest eruptions on Io. “These new events are in a relatively rare class of eruptions on Io because of their size and astonishingly high thermal emission,” Davies said. “The amount of energy being emitted by these eruptions implies lava fountains gushing out of fissures at a very large volume per second, forming lava flows that quickly spread over the surface of Io.”
Researchers say that the temperatures of the magma are close to the temperatures of lava flows that would have been present on Earth during its formative years. A third study is being completed that examines a decade of observations of Io from both the Keck II and Gemini telescope facilities. It covers the multiple hot spots, and the changes on Io’s surface due to the events.
To read the studies, check out the journal Icarus.
Updated to correct the size of Io.