of us are familiar with "Old Faithful" in Yellowstone
National Park. This famous geyser erupts several times a day.
It spouts a column of water heated by volcanic rock deep within
the Earth's crust.
hydrothermal vent is a geyser on the seafloor. It continuously
gushes super-hot, mineral-rich water that supports a diverse
community of organisms. Although most of the deep sea is sparsely
populated, vent sites teem with a fascinating array of life,
from tubeworms taller than you to ghost-white crabs.
vents were discovered in 1977 in the Pacific Ocean. Since then, they have been found in the Atlantic, Indian, and most recently, the Arctic Ocean. Most occur at an average depth of about 2,100 meters (7,000 ft) in areas
of seafloor spreading along the Mid-Ocean Ridge system the
underwater mountain chain that winds around the globe.
do hydrothermal vents form? In some areas along the Mid-Ocean
Ridge, the huge plates that form the Earth's crust are moving
apart, causing deep cracks in the ocean floor. Seawater seeps
into these openings and is heated by the molten rock, or magma,
beneath the crust. As the water heats up, it rises.
this "hot spring" gushes out into the ocean, its
temperature may be as high as 360°C
(680°F). Yet this
water does not boil because it is under so much pressure from
the tremendous weight of the ocean above.
top some vents. These smokestacks are formed from dissolved
metals that precipitate out (form into particles) when the
super-hot vent water meets the surrounding seawater, which
is only a few degrees above freezing.
are intrigued by how rapidly vent chimneys grow as much as a whopping 30 centimeters (12 in) a day! "Godzilla," a vent chimney in the Pacific off the Oregon coast, reached the height of a 15-story building before it toppled and has since been actively rebuilding. In 2000, University of Washington scientists discovered even taller chimneys, up to 55 meters (180 ft) high in the "Lost City" vent field in the Atlantic Ocean.
are many other reasons why scientists want to learn more about
hydrothermal vents. These underwater geysers are believed to
play an important role in the ocean's temperature, chemistry,
and circulation patterns.
also are fascinated by the unusual life that inhabits vent
sites. These creatures who live in darkness, from bacteria
to tubeworms, may light the way to the development of new drugs,
industrial processes, and other products useful to us all.