We continued our core sampling today.  During a break in operations, J.P. Walsh of East Carolina University explained how the sampling device works.

Basically what it consists of is a frame with corers mounted on a weight stand.  While the multi-corer is sitting on the deck, the weight stand is sitting on safety pins, which prevent it from lowering to the deck.

Detail view of the multi-corer with corers and weight stand

When we deploy the multi-corer, a winch lifts it so the frame is off the deck, and then we remove those safety pins. Using the ship’s A-frame and winch (operated from the bridge), we move it out over the water and lower it to the sea floor. When it reaches the sea floor (which is approximately 2,000 meters deep where we are sampling today), the frame hits the sea floor first and stops moving.  The heavy center column, unrestrained by the safety pins, continues to move and is pushed downward because of the weight of the lead on top of the column, forcing the eight corers into the sediments.

Removing safety pins from the corer

Then, when we take it up, we have a device that releases caps to seal both ends of the corers.  In an ideal situation, we get a nicely preserved sample of sediment, with a little bit of water on top.

Corer capping device

In an upcoming post, we’ll show you what we do with the samples once we bring them on deck.