Workshop Report - Ridge 2000 Program

detailed investigation of the seafloor and the subsurface
crust. High temperature hydrothermal vents. for instance. were
discussed only as theoretical possibilities before their
discovery in the Pacific in the late 1970s. Such vent fields
and their associated biological communities were not observed on
slow spreading ridge crests until 1985. High resolution swath
mapping and side-scan sonar imaging have only recently begun to
yield a rich return of information on the detailed morphology
and structure of ridge systems. including such discoveries as
the existence of overlapping spreading centers and major
along-strike variations in volcanic and tectonic processes.
Multi-channel seismic imaging techniques have advanced to the
stage where widespread mapping of the prominent reflector
thought to mark the roof of the axial magma chamber has been
initiated. The Global Positioning Satellite system promises to
reduce ship navigational errors to a few tens of meters on a
routine basis. permitting easy intercomparison of data sets and
assured placement of instrumentation for experiments.
Much of the promise of this new technology remains to be
realized. Detailed sampling and mapping of the mid-ocean ridge.
for instance. has been confined to date only to a small fraction
of its total length. The range in diversity of volcanic and
tectonic processes manifested along the ridge axis. as a consequence.
has not yet been fully defined. More fundamentally.
the complex and interlinked processes of magmatism. hydrothermal
circulation. development of vent communities. and lithospheric
evolution are only dimly understood. The dynamics of these
processes have not yet been elucidated because of the lack of
in situ observations of sufficient duration and diversity to
determine the important interactions and time scales.
For these reasons. the Ocean Studies Board convened a workshop
on the mid-ocean ridge. The workshop participants were
asked to summarize our current understanding of the processes of
generation and evolution of oceanic lithosphere. to identify the
primary objectives for ridge crest science in the next decade.
and to outline a research program capable of meeting these
objectives. The workshop proceedings presented here are the
response to that charge.
In organizing the workshop. the Steering Committee attempted
to assure that a wide spectrum of views from the entire oceanographic
community would be represented. More than 80 individuals
representing physical. chemical. and biological oceanography
and marine geology and geophysics were invited to participate.
The list of participants is included in Appendix I.
Before the workshop. a number of participants were asked to
prepare papers on the state of our understanding of the
principal dynamical processes occurring at the mid-ocean ridge.
with an emphasis on the major scientific questions currently
outstanding. Additional papers were solicited on promising
techniques for addressing these questions. The background
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