Mountains of Io

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.

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.

Due to a strong tidal heating, Io is very geologically active and is volcanically resurfaced by lavas and plume deposits at a high rate (about 1 centimetre (0.39 in) per year).

[6] The thrust faulting and uplifting of large crust blocks on Io are interpreted by a model proposed by Schenk and Bulmer's 1998 paper.

Violent volcanic activity brings lava to the surface and older, buried layers are forced to subside.

The bedrocks are fractured due to tidal flexing, compression at depth, volcanic intrusion and other mechanisms, and then are broken into large blocks a hundred kilometers across.

Products of magmatism like sills, dikes and batholiths may intrude into layers of stacking volcanics to form a composite crust.

Compression at depth due to global burial and subsidence can also form ductile deformation like folding of crust.

[8][9] Localized regions of up-welling and down-welling of mantle material could affect the stress field in Io's lithosphere.

Buoyant mantle diapir can locally enhance the compressive stress which may be sufficient for the development of thrust faults.

Map of the surface of Io, based on images from the Galileo and Voyager missions.
Patera and plateau on Io. NASA's Galileo spacecraft acquired the images in this mosaic of Hi-iaka Patera (the irregularly shaped, dark depression at the center of the image) and two nearby mountains on November 25, 1999, during its 25th orbit. The sharp peak at the top of the image is about 11,000 m (36,000 ft) high, and the two elongated plateaus to the west and south of the caldera are both about 3,500 m (11,500 ft) high. The ridges on the northwestern mountain are often seen on Ionian mountains and are thought to be formed as surface material slides downslope due to gravity.
Resurfacing process on Io. Enormous tidal heating causes Io's highly active volcanic activities. Newly generated surfaces push old surfaces inwards. Major stresses related to this process are labeled in this image. [ 6 ]
Geodynamic model of Io. Violent volcanic activities cause rapid resurfacing on Io. Newly formed surfaces keep pushing the older layer inwards. As the older layer is squeezed to a smaller sphere, horizontal compressive force cause shortening (horizontal contraction) at the older layer.
"Steeple Mountain" on moon Io
(animation; JunoCam; 0:14; 18 April 2024)