Minerals Report - International Seabed Authority

CHAPTER 10
NATIONAL AND INTERNATIONAL PROGRAMMES FOR
THE INVESTIGATION OF SEAFLOOR HYDROTHERMAL ACTIVITY:
THE CURRENT INTERNATIONAL STATE-OF-THE ART
Dr. Chris German, Southampton Oceanography Centre
Southampton, United Kingdom
This paper summarises the work currently undertaken by national and
international programmes to continue the search for new fields of
hydrothermal activity along mid-ocean ridges throughout the world’s deepoceans;
to understand the geological processes which control the distribution
of these vent-sites through the world’s ocean basins; and to determine their
role in maintaining the global vent ecosystem. First, I provide a brief
overview of the nature of hydrothermal venting. Next, I discuss the likely
geologic processes which can determine where hydrothermal massive
sulphide deposits are formed, their likely contribution to the formation of
large versus small deposits, and the principal international expeditions which
are to be conducted in the coming years, informed by these considerations. In
the following sections I described the theory and currently adopted “bestpractice”
methods of prospecting for new sites of hydrothermal activity,
followed by a discussion of some novel low-cost approaches that one could
follow to achieve some simple but fairly reliable first-order value-judgements
concerning the likely resource potential of any new hydrothermal fields.
Finally, I close with a brief warning of the limitations of the (academicallydriven)
best-practices described throughout this paper which should not be of
significant concern to those interested in the search for polymetallic massive
sulphide deposits along mid-ocean ridges throughout much of the Area, but
which are likely of greater relevance to those interested in searching for
similar deposits not only within individual member states’ exclusive
economic zones (EEZ) but also within certain extensions to legal continental
shelves (ELCS).
INTERNATIONAL SEABED AUTHORITY 376