by Cornel De Ronde
On January 4, 1999, pilot Blee Williams, geologist
Cornel de Ronde and helium expert Ron Greene descended into the
murky depths of the Pacific Ocean in the deep submersible vehicle
Alvin. They were in search of hot springs, or black smokers,
known to exist more than 2.6 km down on the bottom of the ocean
The target of the dive is known as the East
Pacific Rise, a long chain of submarine mountains that stretch
many thousands of kilometers from the north Pacific to Antarctica.
Eruptions of hot lava onto the crest of this oceanic mountain
chain are quite common. Cold seawater seeps through deep cracks
in sea floor and is heated by the hot lava.
An hour and a half after beginning the descent,
the three passengers aboard Alvin found themselves peering out
of the small portholes and trying to see their first images of
the sea floor. The pilot turned on the exterior floodlights and
the sonar told them that the bottom was only 50 meters away.
And there it was!
Directly beneath Alvin were various lava flows,
described as 'lobate flows', reminiscent of toothpaste being
squeezed from the tube.
The submersible moved and soon came upon a
very steep wall that had a series of vertical steps each about
eight to ten meters tall, with the intervening slopes covered
by talusjumbled, broken fragments of lava. Later the site
was dubbed "Wall Street."
After a short while the three explorers found
what they had been seekingnumerous chimneys belching out
thick clouds of black smoke that rose into the seawater for 200
meters. The hydrothermic fluids pouring from the chimneys, or
vents, exceeded 350°C, hot enough to have various metals
such as copper, lead, zinc and sometimes gold dissolved in the
When this hot water mixes with the cold (around
2°C) ambient seawater, chemical reactions take place and
the metals no longer stay in solution but precipitate out as
very small, metal-rich, particles. Hence the name black smokers,
as the chimneys (typically one to twelve meters in height with
their vigorous plumes of black smoke) look remarkably like smoke
stacks in an industrial area.
The scientists directed the pilot to the next
target and the next five to six hours were spent sampling the
hot water gushing from vents and retrieving pieces of the metal-rich
chimney for chemical analyses in the laboratory. All of the samples
were taken with the robotic manipulator arms on Alvin, expertly
controlled by the pilot. Extensive videos were taken, chimney
structures and the surrounding geology were mapped and some crabs
and worms were collected for the biologists back on Atlantis.
All-in-all, the time spent on the bottom was
hectic and passed far too quickly. It was spent in a world so
vastly different and removed from what we know on the surface
of the Earth that the three divers could imagine being on another
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