What is a geyser?

A geyser is classified as an intermittent fountain that ejects water. This phenomenon occurs due to the buildup of steam pressure within an underground chamber. When the pressure becomes sufficiently high, it forces water to the surface, resulting in a spectacular eruption that can reach significant heights.

This definition captures the essential characteristic of geysers, which differentiate them from other geothermal features. Unlike a continuous hot spring, which flows steadily, or a warm water spring that is consistently active, geysers operate intermittently, with periods of activity followed by phases of rest. Similarly, they are not classified as artesian wells, which rely on groundwater pressure in confined aquifers, rather than boiling water and steam. Understanding these distinctions helps clarify why the chosen definition accurately represents what a geyser is.