IODP Expedition 328:
Cascadia A-CORK Observatory
Week 1 Report (5-11 September 2010)
PDF file is available for download.
Expedition 328 began at 0836 hr on 5 September 2010 when the
first line was passed ashore at Ogden Point Pier A in Victoria, B.C. After
quickly clearing customs and immigration formalities, the normal crossover
activities began with the IODP crew change.
The routine handling of on-going and off-going shipments
included the disposition of hardware from Expedition 327 and loading of
Expedition 328 ACORK-related equipment. Maintenance activities included
replacement of the inboard logging sheave in the derrick. During the procedure
it was discovered that the new shaft was too short. The old shaft was inspected
and deployed with the new sheave and will be replaced when the vessel returns
to Victoria. At that time the outboard sheave will be also be replaced. This
work is being done in accordance with the Schlumberger maintenance
The vessel departed Victoria for Site U1364 (CAS-01CORK) when
the last line was released at 1606 hr on 9 September. After maneuvering away
from the pier, the vessel began the short 145 nmi transit to the site at 1700
hr. The ship arrived on location at 0600 hr on 10 September concluding a
transit that averaged 11.2 knots.
The initial operational objective was to perform a jet-in
test to verify the water depth and establish the conductor casing length to be
deployed with the re-entry cone. The VIT was deployed to observe the bit
contacting the seafloor at 1329.0 mbrf, and the jet-in test was conducted
reaching 55 mbsf. The re-entry cone and 53 m of 16 inch casing were then
successfully jetted in.
The operational objective of Expedition 328 is the
installation of a new permanent hydrologic borehole observatory near Ocean
Drilling Program Site 889. The format of the new installation will follow the
Advanced CORK (ACORK) design, which will facilitate pressure monitoring at
multiple formation levels on the outside of a 10-3/4 inch casing string.
The casing will be sealed at the bottom, leaving the inside available for
future installation of additional monitoring instruments. The successful
installation of the observatory will allow documentation of the average
state of pressure in the frontal part of the Cascadia accretionary prism, the
pressure gradients driving flow from the consolidating sediments, the mode
of formation of gas hydrates, the influence of gas hydrates and free gas on the
mechanical properties of their host lithology, the response of the material to
seismic ground motion, and the magnitude of strain at the site caused by
episodic seismic and aseismic slip in this subduction setting. At a later date,
the observatory will be connected to the NEPTUNE fiber-optic cable for power
and real-time communications from land.
Portcall activities included introductory and
operational/engineering meetings. Pressure instrumentation was installed on the
ACORK and the plumbing was pressure tested.
Outreach and School of Rock
During port call, a press conference and nine ships tours
were conducted for the public, IODP-Canada, and the US National Research
Council Committee on Scientific Ocean Drilling. Several media hits from the
press conference beyond those in attendance have resulted. IODP-Canada
sponsored lectures and a reception on scientific ocean drilling the evening of
The Expedition 328 School of Rock participants have been
spending their busy12 hour shifts in a variety of ways that take advantage of
the unique expertise and resources on board the ship. From a selection of cores
shipped from the Gulf Coast Repository, participants have been recording
observations and describing sediment smear slides that they will to use to make
inferences about the past sedimentation history of the Pacific Ocean. Through
daily Science Cafes and "field trips" facilitated by a range of ship personnel,
instructors, staff scientist, laboratory technicians, ship staff and
participants themselves, the group has explored a range of topics that relate
to the current expedition, scientific ocean drilling, and communicating
science. The 18 participants are developing their education and outreach plans
that will involve taking various aspects of their experience and translating it
into usable programming and/or activities for different audience. These
products will be hosted from the Deep Earth Academy website.
Technical Support and HSE Activities
The weekly fire and boat drill was held as scheduled.
Staff provided support for science, education and
engineering projects. Laboratory projects in progress included receiving and
stowing shipments from the port call. Supplies are being sorted in preparation
for the South Pacific Gyre expedition. The Liquid Scintillation Counter (LSC)
was installed in the microbiology isotope van and all equipment in the van was
tested. A new towed magnetometer was temporarily installed on the fantail, the
supporting electronics were installed in the underway laboratory and the
software was configured and tested. Permanent installation is ongoing.