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NeMO-ROPOS
Cruise:
This year's NeMO-ROPOS cruise will briefly visit the Cleft segment of
the Juan de Fuca Ridge before going on to NeMO at Axial volcano. At Cleft,
we will deploy an array of new instruments, which will be part of another
seafloor observatory effort sponsored by the NSF/RIDGE Program. Once at
NeMO, we will use ROPOS to continue the time-series measurements we have
been making on the seafloor since the January 1998 volcanic eruption.
This includes taking samples of hydrothermal vent fluids, the microbes
that live in them, and the animals that live around them. In 1998, we
were able to witness the creation of new hydrothermal vent sites and the
first biological colonizers on the new lava flow. Since then we have been
returning each year to document how these sites are continuing to change
and evolve. We will also be recovering and redeploying a variety of seafloor
instruments (including an upgraded near-real time NeMO Net camera system)
that allow us to continue our observations of hydrothermal and geological
processes between our summer NeMO expeditions. Finally, we will be continuing
our high- resolution geologic mapping of the 1998 eruption site, and will
begin some new geophysical measurements to tell us if Axial volcano is
already inflating with magma and getting ready for its next eruption.
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NeMO-CTD
Cruise:
The NeMO-CTD cruise will also visit NeMO (Axial Volcano)
and the Cleft segment of the Juan de Fuca Ridge. At Axial Volcano we will
be making our fourth ctd-cruise since the eruption of January, 1998. We
are constructing a time series of observations of hydrothermal activity
to understand how vent fields evolve after an eruption. Work there will
consist of two principal activities: water sampling and seafloor mooring
recoveries and deployments. The water sampling will consist of vertical
profiles and near-seafloor tows of instruments to map and sample emissions
from hydrothermal vents that form extensive plumes in the deep water around
the volcano's summit. Water samples will be analyzed for gases, trace
metals, microbiological activity, and suspended particulate matter in
order to map the distribution of the plumes. Moorings left at the summit
in 1999 will be recovered and the data downloaded at sea. New moorings
will be deployed for recovery in 2001. These moorings monitor the fate
of the plumes between our yearly cruises.
At the Cleft segment we
will be doing similar work to maintain a time series that began in 1986,
when a volcanic eruption is believed to have occurred there. Our tracking
of hydrothermal activity there is longest such time series anywhere on
the seafloor.
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