This adds up to an orientation with respect to the Sun somewhat like Uranus 's with polar and equatorial regions alternately pointing toward the Sun. This probably results in radical seasonal changes as one pole then the other moves into the sunlight. During the Voyager 2 encounter, Triton's south pole was facing the Sun. A thin haze extends up 5-10 km. At this temperature methane, nitrogen and carbon dioxide all freeze solid.
T here are extensive ridges and valleys in complex patterns all over Triton's surface.
The eruptive material is probably liquid nitrogen, dust, or methane compounds from beneath the surface. It's also interesting to note that very different volcanic processes occur in the outer solar system. Io's eruptions are probably sulfur or sulfur compounds driven by tidal interactions with Jupiter. Triton's eruptions are of very volatile compounds like nitrogen or methane driven by seasonal heating from the Sun. Voyager 2 observed Triton only briefly.