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National News
Korea
Sung-Hyun Park
Korea completed three ridge-related cruises on the Antarctic,
Western Pacific and Indian Oceans. The good news is that KOPRI
is starting a large three-year project on the exploration of the
Australian-Antarctic Ridge (South of Tasmania). We are planning
two more cruises on the Australian-Antarctic Ridge including AUV
surveys.
1) Australian-Antarctic Ridge
KOPRI (Korea Polar Research Institute) conducted a research cruise
on one segment (KR1) of the Australian-Antarctic Ridge in
December 2011. 32 MAPRs and rock cores were done and a
hydrothermal vent site was located more precisely. Also a multibeam
map was expanded around the axis. We tried CTD sampling
from a potential vent site and found the signals of methane and
3He. The next cruise is scheduled in Jan-Feb 2013, and we will try
more CTDs, camera tows and dredges.
2) Central Indian Ridge
KORDI (Korea Ocean Research Institute) performed an
exploration for hydrothermal vents along the northern Central
Indian Ridge (CIR), 8º-12ºS in November-December 2011. The
exploration was focused on the identification of a location of
hydrothermal plumes that were investigated by previous cruises
using CTD Toyo attached with MAPRs. During the survey, at least
8 hydrothermal plumes were identified along the 7 ridge segments
of the northern CIR. Most plume signals were hosted by ultramafic
rocks exposed on the seafloor by the formation of Ocean Core
Complexes (OCC).
3) Tonga Arc
ROV (ROPOS of CSSF) surveys were performed along the
hydrothermal vents on the two seamounts of Tonga Arc in January-
February 2012. Detailed bathymetric data were obtained by
ROV-mounted multibeam survey in the 1st leg. Visual surveys and
sampling of active and inactive hydrothermal vents were performed
in the second leg. During the ROV survey, more than 100 individual
hydrothermal vents were observed in the two submarine calderas.
Mauritius
Daniel E.P. Marie
Recent joint collaborations between scientists of the Mauritius
Oceanography Institute (MOI), Japan Agency for Marine-Earth
Science and Technology (JAMSTEC) and University of Tokyo have
resulted in the discovery of new hydrothermal sites on the Central
Indian Ridge (http://www.plosone.org/article/ info%3Adoi%2F10.
1371%2Fjournal.pone.0032965). Further geological and biological
investigations have been undertaken since then. Thus the existence
of four known hydrothermal sites on the Central Indian Ridge (CIR)
provided a unique opportunity to look at the ecological settings as
well as faunal composition. Preliminary results have also been
presented during the 7th WIOMSA Symposium held in Mombasa,
Kenya (24 th - 29 th October 2011) with the title “Biodiversity at
Hydrothermal Vents along Central Indian Ridge Revised: New
Discoveries, New Perspectives”. Recent data analysis by Mr. Girish
Beedessee (MOI), Dr. Hiromi Watanabe (JAMSTEC) and Dr. Ken
Takai (JAMSTEC) has tried to explain the dispersal abilities of
several invertebrates from these four vent sites. The Central Indian
Ridge has been poorly investigated, in terms of its geology and
biology when compared to other ridge systems and such studies aim
to attract the scientific
community for further
explorations within the CIR.
A cruise devoted to re-visit
the new hydrothermal vents
is planned for 2013 and this
collaboration is a fine
example of how scientists
can work together to
unravel the hidden chemical
and ecological diversity. We
hope the next cruise will
bring exciting news,
revealing new insights of
the CIR.
Daniel Marie, Mauritian
National Correspondent for
InterRidge
INTERRIDGE NEWS 41 VOL.21, 2012