Minerals Report - International Seabed Authority

athymetric map of the seafloor. A side-scan sonar system would be used to
obtain information on the reflectivity of the seafloor, making it possible to
distinguish false CARPS from sedimented areas, and larva flows from
sedimented ponds. The information on the reflectivity of the seafloor would
then be translated into a tectonic map. A deep-towed video camera system
would be utilized to provide on-line observation of the seafloor. The systems
would be attached to a research using with coaxial cable or fibre optic cables.
In his slide presentations, Professor Herzig illustrated the operational
aspects of the systems and the deployment of various types of sediment corers
and grabs. He explained that for manganese nodule exploration, a free-fall
grab system was commonly deployed. For sampling sulphide sediments,
Professor Herzig explained that the system has to be modified as in the case of
land mining operations. He gave an overview of various research vessels and
how they have operated, including the different types of equipment used for
the collection of sediment cores and water samples.
He stated that drilling of seafloor polymetallic sulphide deposits is
essential to obtain samples and information from the interior of hydrothermal
mounds and chimney complexes. The drilling vessel JOIDES RESOLUTION
operated by Ocean Drilling Programme at Texas A&M University had carried
out scientific drilling at the Middle Valley sulphides deposits on the Juan de
Fuca Ridge, offshore Canada during the TAG Programme. He explained that
in addition to drilling vessels such as the JOIDES RESOLUTION, first
generation portable seafloor drilling and coring systems are now available,
jointly developed and constructed by a team from the United States of
America and Australia. The performance specifications of this portable
remotely operated is a maximum penetration of 100 m at an operating depth
of around 2,000 m on rock core diameter of 40mm. A second drill, called the
Benthic Multicoring System, has been constructed by a team from Australia
and Japan and is installed on the research vessel Hakurei, Maru No. 2. This
system uses conventional diamond rotary–rock and soil sampling tools. It can
operate at water depths of 6,000 m. Individual cores have a diameter of 44
mm at a maximum coring depth of 20m. Professor Herzig’s presentation
covered a wide variety of deep sea submersibles starting from JAGO with
depth capability of 400 m. to the Nautile, Mir1 and Mir2, and Shinkai which
can go up to depths of 6000 to 6500 m.
INTERNATIONAL SEABED AUTHORITY 36