Minerals Report - International Seabed Authority

Professor Rona recalled that the initial hot springs that were
discovered were along the axis of the East Pacific Rise where the hot material
wells up at a relatively fast spreading rate. He stated that the East Pacific Rise
is part of the Pacific Ocean basin referred to as the “Ring of Fire” because it is
the most volcanically active region of the earth. He further stated that after
this discovery, it was initially felt among the scientific community that slower
spreading centres in the Atlantic and Indian Ocean mountain ranges would
not have hot springs.
Dr. Rona described an expedition that he led that resulted in the
discovery of the first black smokers, polymetallic massive sulphide deposits,
and vent ecosystem in the Atlantic while overcoming the consensus of the
scientific community that such phenomena could only occur in the
volcanically more active Pacific. He pointed out that his team had certain
clues that there should be hot springs in the Atlantic such as where the
submerged volcanic mountain range projects above water in the island of
Iceland.
Professor Rona described the exploration strategy used by his team to
discover the TAG hydrothermal field on the Mid-Atlantic ridge, the first hot
springs and massive sulphides deposits found anywhere in the deep Atlantic
Ocean. He acknowledged the strong support that the team obtained from the
United States National Oceanographic and Atmospheric Administration
(NOAA), which provided various instruments for remote and direct sensing
of the seafloor. He also provided participants with a broad view of how
various techniques were used in the discovery of the TAG deposits.
The strategy outlined by Professor Rona for finding an actively
forming deposit consisted of using knowledge of the seafloor province where
such a deposit could occur and utilizing the physical and chemical properties
of the deposit to identify its exact location.
To address the question of where hot springs may be found on the
mid-Atlantic ridge, Dr. Rona said that one of the tools used were water
samples. If there were indeed hot springs, metals from the hot springs would
be carried out by currents for hundreds of kilometres. Elevated levels of
certain metals would indicate the presence of hot springs somewhere on the
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