Old Faithful Geyser

How geysers work

Geysers are generally located on the edges of the Earth’s tectonic plates. These plates are unstable, generating tremendous energy that erupt at fault lines. This dynamic can result in earthquakes and volcanoes; it also provides heat sources for geysers and hot springs. Geysers require water, heat, and a plumbing system. Many geysers are located near rivers and draw water from them. The water in geysers is heated by magma that lies around 3 miles (4.8 km) beneath the surface of the Earth.

Key Components of Geyser Formation

In order to survive, a geyser needs a consistent flow of groundwater into its natural plumbing system. A geyser also needs a constant heat source. Geysers live in only a few places on Earth where there is high geothermal activity from active volcanic fields. It is the energy from this geothermal activity that creates the heat geysers need to fuel their eruptions.

Sequences of a Geyser

Much like a natural pressure cooker, a geyser’s eruption is powered by an explosion of boiling hot water and steam. Groundwater held in the geyser’s main chamber is heated by magma deep under the Earth’s surface. An explosive eruption occurs when the water reaches extreme temperatures under increased pressure from a build-up of steam. The eruption releases pressure and allows the geyser to cool.

1) FILLING: Groundwater seeps into the geyser’s reservoirs, a series of underground chambers which are emptied by previous eruptions.

2) WARMING: As groundwater enters the reservoirs, it is heated by nearby magma bringing it to temperatures that can exceed 199°F (93°C).

3) BOILING: Intense pressure compounded by depth of the reservoirs and weight of the water, creates steam yet prevents the water from boiling.

4) ERUPTING: The steam expands and lifts the water upward causing the geyser to overflow. This release decreases pressure, induces violent boiling, and forces a massive amount of steam and water out of the vent. Then the process repeats.