In the case of Enceladus, the plumes are believed to be driven by internal energy. There are also signs of carbon dioxide eruptions from the southern polar ice cap of Mars. Water vapor jets have been observed near the south pole of Saturn's moon Enceladus, while nitrogen eruptions have been observed on Neptune's moon Triton. Due to the low ambient pressures, these eruptions consist of vapor without liquid they are made more easily visible by particles of dust and ice carried aloft by the gas. Jet-like eruptions, often referred to as cryogeysers, have been observed on several of the moons of the outer solar system. Like many other natural phenomena, geysers are not unique to planet Earth. The resultant boiling of the pressurized water results in the geyser effect of hot water and steam spraying out of the geyser's surface vent (a hydrothermal explosion).Ī geyser's eruptive activity may change or cease due to ongoing mineral deposition within the geyser plumbing, exchange of functions with nearby hot springs, earthquake influences, and human intervention. Generally, surface water works its way down to an average depth of around 2,000 metres (6,600 ft) where it contacts hot rocks. Generally all geyser field sites are located near active volcanic areas, and the geyser effect is due to the proximity of magma. As a fairly rare phenomenon, the formation of geysers is due to particular hydrogeological conditions that exist only in a few places on Earth. A geyser ( / ˈ ɡ aɪ z ər/, UK: / ˈ ɡ iː z ər/) is a spring characterized by an intermittent discharge of water ejected turbulently and accompanied by steam.