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This is an image of the volcano Loki.
Click on image for full size

Volcanism of Io

Io is actively volcanic. As shown in this picture, the surface is formed almost entirely of volcanic flows or pools of volcanic material. It was during the Voyager mission to Jupiter that the active volcanism of Io was first discovered. The activity of Io was a major surprise. Io is the only body in the solar system other than the Earth known to be actively volcanic.

The volcanism of Io provides another example of a prominent kind of volcanism found on Earth, namely the formation of geysers. The two kinds of volcanism exhibited by Io are:

  • volcanoes, which form from silicate magmas similar to those of Earth
  • geysers, spouting liquid SO2.

Hotspots of Io reveal where the volcanoes are. The most well known and active volcanic features of Io are:

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Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA