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IODP Expedition 321:
Pacific Equatorial Age Transect 2
Week 1 Report (4-9 May 2009)
PDF file is available for download.
10 May 2009
the Pacific Equatorial Age Transect (PEAT II), officially began at 0736 hr 4
May 2009 with the first line ashore Pier 2B, Honolulu, Hawaii. The JOIDES
Resolution (JR) arrived a full day early
having been scheduled in at 0700 hr 5 May. The early arrival added a bonus day
to a schedule that already was planned as a 4-day port call.
The ship arrived
with two propulsion motors out of service requiring field coil replacement.
This was the first priority activity upon arrival. The first day also included
offloading of all refrigerated core samples and replacement of the logging
winch transmission. During port call, vender representatives were aboard
working on the elevator replacing mechanical interlocks with a solenoid
actuated variety, HVAC system balancing, and Rigwatch rig instrumentation
system repairs and calibrations. The normal on and offloading activities took
place including the loading of 10 short tons of Attapulgite drilling mud left
over from the Honolulu 1 port call and 1537 metric tons of marine gas oil were
bunkered. Training was conducted on the Rigwatch RIS system and on operation of
the Schlumberger logging line winch and wireline heave compensator systems.
Other activities included a Det Norske Veritas (DNV) International Safety
Management (ISM) audit of the ship and CDEX engineers came aboard to discuss
the JR core winch regenerative braking system and the JR's coring tools.
were conducted dockside at the Pier 2B cruise ship terminal, the Waikiki
Aquarium, and the Marriott Hotel Waikiki. These included several high level
dignitaries and other management personnel including the Director of the National Science Foundation, Ocean Leadership, the University of Hawaii, and Texas A&M University. Ship tours were conducted
for dignitaries as well as University of Hawaii faculty and students, and high
school students and teachers.
departed Honolulu with the last line away from Pier 2B at 0512 hr.
Approximately 10 nm offshore the ship switched over from cruise mode to DP
control, lowered thrusters, and 7-3/4 hr of DP trials were conducted to
optimize the system performance after changes in the ship profile were made
during the Singapore refit. During this period a representative from L3, the
Nautronics parent company, collected data and made adjustments to the internal
windage modeling program that impacts the anticipatory commands of the system.
The vendor was transfered from the JR to the V/L Karake at the Honolulu Harbor outer sea buoy and at 1636 hr the vessel got underway for Site U1336 (PEAT-5C). Transit speed en route to the first site averaged 10.7 knots over the 79.0 nm covered by midnight on 9 May 2009.
The equatorial Pacific is a major locus of solar warming, a
region of high primary productivity, and a primary region for CO2
exchange from the deep ocean to the atmosphere. It is also the source region
for one of the strongest multiyear climate oscillations, the el
Ni–o-Southern Oscillation. The wind-driven
circulation and productivity system of the equatorial Pacific are sensitive to
climate change. The equatorial Pacific also helps to maintain global climates
and drive climate change as well.
Over the past 55 million years global climate has varied
dramatically from extreme warmth to glacial cold, and these climate variations
have all been imprinted on the biogenic-rich sediments that accumulate in the
equatorial zone. The Pacific Equatorial Age Transect (PEAT, IODP Expeditions 320 and 321) is recovering
sediments to study equatorial Pacific circulation and productivity at a time
resolution where the effects of orbitally driven solar insolation cycles can be
PEAT drilling will help scientists to understand how the earth maintained very warm climates in the distant past relative to the 20th
century even though solar heating has remained nearly constant in that time
frame. PEAT drilling will also help scientists understand earth's transient
response to large changes in greenhouse gas composition during several
important events in the Cenozoic.
Expedition 321 is the second part of the PEAT program and
will explore the time period from roughly 25 Ma forward. Drilling, coring and
logging are planned at Sites PEAT 7C and 8C. Between 25 and 12 million years
ago global temperatures were much warmer than modern conditions and the water
cycle was stronger, but CO2 was only slightly elevated relative to
the Holocene. Understanding how the equatorial Pacific upwelling system
operated under warm temperatures but moderate CO2 levels is one of
the primary objectives of Expedition 321.
The equatorial Pacific ecosystem underwent several important
transitions that are poorly understood with respect to climate. Another primary
objective is to understand the relative importance of changes in ocean
configuration (tectonics) vs chaotic climate drivers to change nutrient
exchange and productivity in the equatorial Pacific. Better constrained age
models will provide critical information about the rates of climate change so
that climate scientists can better understand the rates of response of
important earth systems. Drilling will also be the ground-truth to calibrate
seismic reflection studies of regional sedimentation to better understand
carbon burial in this important locus of sedimentation.
The scientists spent the first week of the expedition
learning their laboratories, instrumentation, documenting methods, and
practicing core flow using Expedition 320T practice core.
Technical Support and HSE Activities
The Expedition 321 technical staff boarded the vessel on May
5 at 0900 hrs. Crossover and training with the off coming crew begun the same
day and continued through the remainder of the port call for most of the
laboratories. Expedition 320 cores were off-loaded on May 4 and D-tube boxes
were loaded. The rest of the freight was loaded during May 5 and 6.
On May 7th an introduction meeting was held with the science
crew. All trash was collected and offloaded before departure. Laboratory safety
and marine mammal observer training were conducted on May 7 and May 8. Equipment
and laboratory spaces were secured for sea prior to departure. The first boat
and fire drill was held on May 9.