GLAD800 Coring From the R/V Knorr
Scientists from DOSECC (the international continental drilling program), Lamont-Doherty Earth Observatory, Skidaway
Institute of Oceanography, and UTIG tested the the GLAD800 lake
drilling system onboard the R/V
Knorr. The Office of Naval Research provided funding because
the New Jersey shelf (1) has long been a geographic area of interest to the Navy,
and (2) is a very difficult place to recover sediments using conventional piston
coring (because the shallow sediments are sandy). The GLAD800 lake
drilling rig will allow scientists to gather long, intact samples for ONR programs
that UTIG investigators
are and have been working on--Geoclutter and STRATAFORM-- and also provide
a "mission-specific" drilling alternative for the upcoming IODP (Integrated
Ocean Drilling Program).
Jamie Austin represented UTIG onboard the
Knorr and sent back several cruise reports. A poster (small-scale or full-scale)
that describes the work in more detail is available.
Jamie's Cruise Reports
Tuesday, 6 November
"As of 1500 EST, Tuesday, 6 November, Knorr remains at the dock,
awaiting improvement of weather. Since yesterday, winds have been out of
the NW at speeds of 25-35 kts. While at the dock, the drilling system has
been tested. Both hardware and software systems are functioning. Two
cores have been attempted - one hydraulic piston core and one "extended
bit" core. The HPC recovered 117 cm of sand with some silt. Cobbles
clogged the core catcher. However, the full stroke of the HPC, ~3m, was
achieved. The "X" core recovered only cobbles and coarse silt in the CC.
We are scheduled to sail at 2000 hrs EST. We will test the DP and
heave compensation systems south of Martha's Vineyard tonight, and proceed
to the Mud Patch near the edge of the shelf to the south at first light
tomorrow, weather permitting. We will not return to WHOI until Saturday
morning, to allow for a robust at-sea test of the system in both muddy and
sandy lithologies in water depths of 70-90 m Wednesday-Friday."
Wednesday, 7 November
"As of 1230 EST on Wednesday, 7 November, the R/V Knorr is still sitting
south of Martha's Vineyard, testing the ship's DP system and the heave
compensation of the GLAD800 drilling rig. One complication is that WNW
winds persist at speeds of 25 kts with gusts to 30 kts. Waves are running
~6-8 feet. Excursions of up to 8 m have occurred in DP mode, in water
depths of ~28 m. The ship is using a DGPS system for primary navigation,
with corrections supplied by Fugro-McClelland. Thus far, results from the
HC system are encouraging. IF winds come down, the ship will proceed
southward to the edge of the shelf by nightfall, and begin drilling in the
Mud Patch at first light tomorrow."
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