as a result of the presence of significant quantities of sulfurous materials in io's crust and on its surface, some eruptions propel sulfur, sulfur dioxide gas, and pyroclastic material up to into space, producing large, umbrella-shaped volcanic plumes. this material paints the surrounding terrain in red, black, and/or white, and provides material for io's patchy atmosphere and jupiter's extensive magnetosphere. spacecraft that have flown by io since 1979 have observed numerous surface changes as a result of io's volcanic activity.