The freeze corer consists of a steel wedge 1.5m tall, ~15cm wide, and ~8cm deep at the top. The wedge is filled with a mixture of dry ice and alcohol, and lowered into the sediment via rope or standard Livingstone drive rods. The corer remains in this position for ~10 minutes while sediment freezes to the outside of the wedge, then returned to the surface. The dry-ice alcohol slurry is poured into a bucket, and the frozen slabs of sediment on the outside of the corer are removed and preserved in a cooler with dry ice. Freeze corers produce exceptional samples of near-surface sediments, which can be difficult to recover without disturbing the fragile sedimentary structures. Corer length determines the maximum depth of recovery.
Instructions for the operation of the Freeze corer.