NSF PR 96-54 - October 3, 1996
Media contact: |
Cheryl Dybas |
(703) 306-1070 |
cdybas@nsf.gov |
Program contacts: |
Bruce Malfait |
(703) 306-1581 |
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Dave Epp |
(703) 306-1581 |
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Scientists Witness Creation of New Hydrothermal Vents
on Seafloor
During a recent National Science Foundation (NSF)-funded
research expedition aboard the scientific drill ship
JOIDES Resolution, two new hot springs were created
on the seafloor. This event reactivated an ancient
hydrothermal system which produced extensive mineral
deposits on or just below the ocean floor.
A group of 25 scientists from nine countries was part
of an Ocean Drilling Program (ODP) research expedition
to study active seafloor hydrothermal systems and
the rich metal deposits they often produce. The ship
drilled about 150 miles west of Vancouver Island,
Canada, when the creation of these new vents occurred.
Although water as hot as 286 degrees C (547F) was
actively being expelled from the seafloor within a
few miles of the drilling location, ODP research focused
on sampling the deposits formed by older, now inactive
vents. "Natural hot springs on the seafloor are formed
when seawater circulates through hot volcanic rocks,
often located where new oceanic crust is being formed,"
explains Bruce Malfait, director of NSF's ocean drilling
program. "Submarine hot springs are in the spotlight
of such intense study because they are places where
deposits rich in iron, copper, zinc, and other metals
form."
"The metal deposits are of great interest to us not
so much because they form a metal resource on the
seafloor, but because of what they can tell us about
how metallic ore deposits that we mine on land were
formed millions of years ago," adds Robert Zierenberg,
a researcher with the University of California, Davis,
and co-chief scientist on this expedition. "Many of
these metal deposits were originally created on the
seafloor and have been pushed up onto the continents
as the Earth's plates collide."
Scientists onboard the JOIDES Resolution inspected
the site of the new hydrothermal vents by lowering
an underwater camera to the seafloor. The new hydrothermal
vents provide an unprecedented opportunity for scientists
to study the life cycle of a seafloor hot spring and
its associated biological community. Naturally occurring
hydrothermal vents are known to have limited life
spans, but how long any given vent lasts, how it evolves,
and how the biological community it supports evolves
is largely unknown. One of the biggest mysteries is
how vent animal communities manage to migrate from
one vent to another. Melanie Summit, a microbiologist
at the University of Washington, says, "We can now
start from time zero and watch how these sites become
colonized. This is our first opportunity to see how
a new hydrothermal vent, and the animal communities
that thrive in these environments, grow and change
with time."
NSF has responded rapidly to scientists' requests
to revisit this area of the Northeast Pacific in the
near future. "This month, scientists will use the
research vessel Thomas Thompson, outfitted with a
robotic vehicle operated from the ship, to study the
geology, chemistry, and biology of these new hydrothermal
vents," says Dave Epp, acting director of NSF's marine
geology and geophysics program.
The international research team will install instruments
in the drill holes to monitor temperature and pressure
changes during the next several years. The data will
be stored in computers on the seafloor and will be
recovered in the future when remotely operated vehicles
(ROVs) or research submersibles visit these sites.
Scientists will then examine the records to see how
events like nearby earthquakes and volcanic eruptions
affect the flow of hot water from the vents.
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