For collecting 1-10 m cores
Vibracoring is one of many subsurface sediment acquisition (sediment coring) techniques, each of which fills a role dependent on task objective and environmental parameters. Vibracoring obtains sediment samples by vibrating a core barrel into the sediment. The advantage of vibracoring is that core depths (up to 10 m) can exceed most small-boat gravity-driven type corers without adding cumbersome weight. Likewise, vibracoring is easier to accomplish and maintain than rotary-drill core methods. The vibracoring process, however, makes penetration success dependent on lithology; pure sands tend to attenuate the vibration of the barrel and slow descent, rock of course will stop descent of the barrel. The vibration will also translate to the core sample itself, and may compact the sediments or disrupt laminations or bedding in the sediment. Other coring techniques should be considered if these factors become an issue.
The vibrator, a STOW Model G550H, is powered by a Honda 5.5 horsepower gas motor. This unit spins a flexible cable at high speed that causes the unevenly weighted head to vibrate. The head is mounted by U-bolts to a weighted adapter that clamps to 3-inch aluminum core barrels. The setup is capable of handling barrels of any length since the adapter can easily be repositioned up the shaft as the core is driven in. Thirty-foot barrels have been the standard maximum length for this operation.
To collect a sediment core for detailed stratigraphic and paleoecological analyses.
STOW Model G550H (engine mounted onto wheelbarrow, vibrating hose, vibrator head), regular unleaded gasoline, head-to-tube bracket, "rabbit ears", 5/16 hex wrench, adjustable wrench, old-style "bumper" car jack, aluminum core tubes, core end caps, duct tape, saran wrap, hacksaw, scissors, knife, sharpie, gloves for all workers, first aid kit
Piston: 3" dia. rubber stopper cut to fit tube and with a drill hole in the middle, 3" long eye-bolt, nut, washer, duct tape, 50' rope.
ON THE DAY BEFORE THE TRIP
DAY OF TRIP