Europa’s plate tectonic activity is unlike Earth’s

Plate tectonics represents a defining framework of contemporary geoscience, accounting for large-scale options on Earth’s floor, akin to mountains and valleys, in addition to the processes that form them, like volcanoes and earthquakes. Current-day plate tectonics haven’t been noticed on another world within the solar system, and proof of previous exercise on planets akin to Mars and Venus is circumstantial. Maybe one of the best case for extraterrestrial plate tectonics is discovered within the floating ice shell of Jupiter’s moon Europa.

Collins et al. present probably the most complete look but at doable plate tectonic exercise on Europa. They prolonged prior work to incorporate extra floor areas and a extra subtle geometric method, basing their evaluation on a world map of Europa derived from photos captured by NASA’s Galileo orbiter.

The staff recognized potential tectonic plates as areas of contiguous geography bounded by floor discontinuities. After figuring out these boundaries, they inferred a time sequence of exercise on the boundaries primarily based on which discontinuities seem to lie atop or crosscut adjoining options. As soon as this sequence of occasions was established, they labored backward from the latest occasion to reconstruct the possible motions of every plate wanted to convey it into alignment with its neighbors.

The researchers utilized this method to 3 areas of Europa that they deemed most promising to have hosted previous tectonic exercise. They discovered that to finest reconstruct the movement of the floor, giant areas suspected to be plates in earlier research needed to be damaged into smaller subplates alongside much less apparent boundaries. This remark helps clarify why some prior research discovered that enormous plates didn’t reconstruct properly or behaved in different sudden methods, the researchers be aware.

The authors draw 4 broad conclusions about plate tectonic exercise on Europa: It’s spatially widespread; it’s regionally confined slightly than globally related; it happens intermittently and isn’t taking place now; and through previous exercise, plates drifted restricted distances of between 10 and 100 kilometers.

Every of those traits distinguishes tectonic activity on Europa from that on Earth. The driving mechanisms for Europa’s plate tectonic system are absolutely additionally completely different. To additional reveal these mechanisms and to reply different questions on Europa, planetary scientists want extra high-resolution observations, the researchers say, which the upcoming JUICE (Jupiter Icy Moons Explorer) and Europa Clipper missions will hopefully present.

The work is printed within the Journal of Geophysical Analysis: Planets.

This story is republished courtesy of Eos, hosted by the American Geophysical Union. Learn the unique story here.