Groundwater - The Changing Earth: Exploring Geology and Evolution - page 350

Geysers
Hot springs that intermittently eject hot water and steam
with tremendous force are known as geysers . The word
comes from the Icelandic geysir, “to gush” or “to rush forth.”
One of the most famous geysers in the world is Old Faithful
in Yellowstone National Park in Wyoming (

With a thunderous roar, it erupts a column of hot water and
steam every 30 to 90 minutes. Other well-known geyser ar-
eas are found in Iceland and New Zealand.
Geysers are the surface expression of an extensive un-
derground system of interconnected fractures within hot
igneous rocks (

Figure 13.22). Groundwater percolating
down into the network of fractures is heated as it comes into

◗

◗ Figure 13.21).

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Figure 13.23 Hot-Spring Deposits in Yellowstone National Park, Wyoming

a Minerva Terrace, formed when calcium-carbonate-rich hot-spring water cooled, precipitating
travertine.

b Liberty Cap is a geyserite mound formed by numerous geyser
eruptions of silicon-dioxide-rich hot-spring water.