Geysers and Dolls

Geysers are a rare manifestation of the powerful volcanic forces that originate deep within Earth’s mantle. While volcanoes are widespread, geysers are more limited in where they can be found. There are about a thousand worldwide, with the highest concentration- roughly half- found in Yellowstone National Park.

Geyser at Yellowstone's Fountain Paint Pot

A volcano is sort of an opening to the mantle. Molten rock (magma) from the mantle is forced up to the surface by pressure periodically. Magma is also the driving force behind a geyser. Surface water trickles down through the soil and rock and collects in deep underground hot spots. Magma beneath the hot spot is what makes the spot hot. It superheats the water that collects there. Steam, heat, and pressure force the water back to the surface. After blasting to the surface, the water and steam continue surging up into the air. You’ve just witnessed a geyser erupting. The water falls back to the ground and percolates into the soil, starting the process over again. Most geysers erupt randomly, but a few run on a fairly predictable schedule. Most famous is Old Faithful, which erupts every 50 to 100 minutes, depending on local water conditions.

Geyser erupting at Yellowstone

Not all groundwater is forced to the surface so violently. Many times is flows gently as either a hot spring or the hotter boiling spring. If it is sufficiently dirty, you’ll see a bubbling mud pot. Sometimes only steam, not liquid water, hisses from the ground as a fumarole. Yellowstone has all of these geothermal features. Yellowstone is considered an active volcano, with the last eruption occurring about 600,000 years ago. Like the Hawaiian Islands, it sits over leaking magma in the middle of a tectonic plate. 

Fountain Paint Pot, a mud pot

Boiling spring at Yellowstone

Fumarole at Yellowstone

Dragon's Mouth hot spring at Yellowstone

Did you know? Some of Yellowstone's boiling springs are home to bacteria known as extremophiles that are adapted to live in extreme conditions. This week’s information comes from National Geographic and USGS.