Mountains of Io

Mountains are widely distributed across the surface of Io, the innermost large moon of Jupiter. There are about 115 named mountains; the average length is 157 km (98 mi) and the average height is 6,300 m (20,700 ft). The longest is 570 km (350 mi), and the highest is Boösaule Montes, at 17,500 metres (57,400 ft), taller than any mountain on Earth.^[1] Ionian mountains often appear as large, isolated structures; no global tectonic pattern is evident, unlike on Earth, where plate tectonics is dominant.

Io is exceptional for the strong tidal heating it undergoes, caused by the eccentricity of its orbit (which results from its resonance with Europa and Ganymede) in conjunction with the proximity and great mass of Jupiter. This leads to widespread and intensive volcanism. Most volcanoes on Io have little relief; those that can be considered mountains are generally smaller than the mountains formed by tectonic processes, averaging only 1,000 to 2,000 metres (3,300 to 6,600 ft) in height and 40 to 60 kilometres (25 to 37 mi) in width. Several geodynamic models of Io exist but the tectonic mountain-building process is still obscure and debatable. However, it is thought to be related to stresses caused by the rapid volcanic resurfacing of the body.