geiser

Geiser, often spelled geyser in English, refers to a hot spring that periodically erupts, ejecting jets of hot water and steam. The phenomenon occurs in hydrothermal systems where groundwater is heated by underlying magma or hot rocks, typically in volcanic or tectonically active regions. Eruptions arise when subterranean water becomes superheated and pressure builds in narrow conduits; when pressure exceeds the strength of the surrounding rock, a rapid release flashes more water to steam and forces a column of liquid and steam to the surface.

Geysers are commonly categorized by eruption style. Cone geysers eject water through a narrow vent lined with mineral deposits, forming a cone-shaped mound; fountain geysers discharge from wider openings, producing a more chaotic spray. The duration and interval between eruptions depend on the heat input, water supply, and the geometry of the underground pathways.

Global distribution is concentrated in areas with recent or ongoing volcanic activity, including Iceland, the United States (notably Yellowstone), New Zealand, Kamchatka in Russia, and parts of Chile. Notable examples include Strokkur in Iceland, Old Faithful in Yellowstone, and Steamboat Geyser, also in Yellowstone, known for its powerful eruptions.

Geisers are sensitive to environmental changes and human disturbance. They are typically protected within national parks or reserves to preserve their fragile hydrothermal systems and warn visitors of eruption hazards. The study of geisers helps scientists understand subsurface geology, fluid dynamics, and geothermal processes.