Figure 1. Overview of cruise track for expedition AT25-04 with R/V Atlantis/ROV Jason II in
Summer 2013. Initial and final port is the same: Seattle, WA. Expedition activities will focus on
sites where long-term, subseafloor observatory systems (CORKs) were installed as part of Ocean
Drilling Program and Integrated Ocean Drilling Program expeditions. Red box indicates area of
Figure 2, showing work sites in greater detail.
AT25-04 prospectus, CORK servicing, Summer 2013
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Figure 2. Bathymetric map showing work area for AT25-04. The primary work sites are located
near the center of the red box (shown in greater detail in Figure 3). These sites are: 1026, 1027,
1301, and 1362. All sites are located east of the Juan de Fuca Ridge, where volcanic rocks are
covered by relatively thick accumulations of marine sediments, making the seafloor relatively
flat in the AT25-04 work area. Also shown on this map are locations where volcanic rock
outcrops penetrate sediment and are exposed at the seafloor. Three of these locations are
secondary work sites, to be visited only if work is completed at the primary work sites and
additional time remains on the schedule: Mama Bare, Papa Bare, and Zona Bare outcrops. In
addition, there could be work at two CORKs closer to the ridge, in Holes 1024C and 1025C, as
shown.
AT25-04 prospectus, CORK servicing, Summer 2013
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Figure 3. Detailed contour chart showing primary work area for AT25-04. All of these work
sites are located within a few kilometers of each other, where the seafloor is relatively flat and
comprises thick marine sediments over basement volcanic rocks. Gold contours show locations
of small volcanic rock outcrops, as labeled.
AT25-04 prospectus, CORK servicing, Summer 2013
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Figure 4. Cartoon showing features of CORK systems deployed during IODP Expedition 327.
Earlier CORKs have some of these characteristics, but Exp. 327 CORKs have additional features
including: perforated and coated drill collars and casing at depth, two kinds of CORK and casing
packers (inflatable and swellable), a casing seal between 10-3/4 inch and 16 inch casing strings,
a tapered gravity plug for a top seal, and a free flow valve in the L-CORK wellhead. Additional
features that Exp. 327 CORKs have in common with the last generation of CORKs deployed on
IODP Expedition 301 include: main CORK seal in the throat of the reentry cone within 10¾ inch
casing, primary CORK casing diameter of 4½ inches, up to eight fluid, microbiological, and
pressure sampling lines, with ports and screens at various depths, and a mixture of fluid and
microbiological sampling systems suspended on Spectra cable at depth. Temperatures are
recorded with autonomous sensor and logging instruments incorporated into the fluid and
microbiological samplers or hung independently from the Spectra cable. The CORK in Hole
1027C is from an earlier generation and lacks casing that extends into basement.
AT25-04 prospectus, CORK servicing, Summer 2013
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Figure 5. Images from AT18-07 in Summer 2011 showing manipulation of pressure
measurement systems on CORK wellheads. A. Lifting the ODI underwater mateable connector
to the data logger mounted on the CORK wellhead in Hole 1301A. B. Cleaning the ODI
connector prior to data download at Hole 1362B. C. Downloading data from pressure logger in
Hole 1362B. D. Placing data logger on ROV platform on CORK in Hole 1027C. This CORK has
a pressure logger oriented horizontally rather than vertically.
AT25-04 prospectus, CORK servicing, Summer 2013
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Figure 6. Images from AT18-07 in Summer 2011 showing manipulation of OsmoSampling
systems on CORK wellheads. A. OsmoSamplers deployed on the wellhead of the CORK in Hole
1026B. B. OsmoSamplers prior to recovery, Hole 1301A. C. New OsmoSamplers deployed on
CORK in Hole 1301A. D. New style OsmoSamplers deployed in milk crates on CORK in Hole
1362A. Manipulator arm is reaching for handle of umbilical (white plastic). E. Final
configuration of OsmoSamplers on CORK in Hole 1362A. F. OsmoSamplers being deployed in
milk crate on CORK in Hole 1362B.
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Figure 7. Images of selected fluid sampling activities during AT18-07 in Summer 2011. A.
Running Large Volume Bag Sampler (LVBS) on elevator adjacent to U1301A. Note gas-tight
sampler being deployed to left of LVBS. B. View of CORK and area around Hole U1301A just
before release of elevator with LVBS. C. Picking up manifold inlet for LVBS positioned on
elevator adjacent to Hole U1362B. D. Placing gas tight sampler inlet in gas trap connected to
LVBS. E. Lifting a squeeze sampler to discharing flowmeter chimney on Hole U1362B. F. Final
configuration of GeoMICROBE sled on Hole U1362B, with adapter for umbilical connected to
lower most fitting. OsmoSampler crate visable to left, is sampling from top of flowmeter
chimney.
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Figure 8. Images from AT18-07 in Summer 2011 showing manipulation of flowmeter system
deployed on CORK in Hole 1362B, and a modified system being prepared for AT25-04. A.
Flowmeter component . A. Jason-II basket prior to dive, showing fluid sampling tools (left),
OsmoSampler crates (center), and flowmeter (right). B. Lifting flowmeter from basket at
U1362B. C. Shimmering water exiting flowmeter at top (inset shows LED during measurement).
D. Squeeze sampler deployed at exit to flowmeter chimney at U1362B. Temperature logger
mounted near top of chimney is visible below sampler. E. Attaching inlet to OsmoSamplers at
top of chimney connected to flowmeter in Hole U1362B. F. New handle assembly attached to
main flowmeter sensor system, being prepared for deployment on CORK in Hole 1362A in
Summer 2013. This handle should improve deployment and recovery operations.
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