There are plenty of weird volcanoes in our Solar System, from icy variants on dwarf planets to pancake volcanoes on Venus. On Io, though, they are utterly bonkers.
These hellish volcanoes, ranging from city-sized pools of lava to gigantic volcanic shields, are all fueled by “hotspots,” towers of superheated material rising up from the depths of a magmatic ocean. Writing in the journal Icarus, researchers at the University of California (UC) Berkeley have announced that they have found a whopping 48 more of them.
Perhaps more remarkably, their new thermal imaging data suggests that when a particularly powerful upwelling sets one of the volcanoes off, it may cause a chain reaction that triggers the eruption of others nearby, or even those a mind-blowing 500 kilometers (310 miles) away. At present, it’s not entirely clear how this is physically possible.
“It’s certainly conceivable that a triggering process could be occurring on Io and not on Earth, due perhaps to differences in the crust or in the plumbing of the volcanoes,” lead author Katherine de Kleer, a UC Berkeley graduate student, told IFLScience.
Even more bafflingly, all of the new hotspots were found on the “back” or trailing side of the moon, and nowhere else. Thermal models suggest that most of Io’s volcanic output should be on the poles or at the equator. Increasing evidence appears to show that this is perhaps untrue, and no one knows why.
In addition to this violence and confusion, Loki Patera, a colossal lava lake over 200 kilometers (124 miles) across, was also found to contain enormous waves. Picture a sea of liquid fire, with solid chunks sinking down beneath the surface and causing a splash – that’s what’s happening here.
Io is nothing short of a poorly understood world of fireworks and iridescent fury. This Jovian moon is covered in many hundreds of volcanic peaks that often spew out sulfur-rich lava up to heights of hundreds of kilometers, thanks to their explosivity, the low surface gravity, and a distinct lack of air pressure.
These lava fountains often manage to reach the cold bastions of space and freeze into blue umbrellas, helping to create a deadly band of radiation that would kill any living thing that encountered it. Even Io’s wafer-thin atmosphere – which is prone to collapsing and inflating – is built up by these sky-high volcanic plumes.
All of this vivacious volcanism is powered by a mechanism known as tidal heating. The orbital dance and interaction of the nearby moons and supermassive Jupiter itself generates a strong gravitational pull on the innards of Io. This produces frictional forces so powerful that it melts solid rock into magma at a ludicrous rate.
Gif in text: All the volcanic outbursts on Io between August 2013 and December 2015. UC Berkeley