University of Minnesota
LacCore
http://laccore.org
(612) 626-7889
myU OneStop


College of Science & Engineering > Dept. of Earth Sciences > Limnological Research Center > LacCore

LacCore home page

Freeze Corer

Description

LacCore freeze corers consist 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.

Additional Files

The Freeze Coring (PDF, 1.5MB) PDF includes further information on the use of the freeze corer and images of it in use.

Images

(Left) The freeze corer in action. (Right) A sample collected displaying the effectiveness of freeze coring.

(Left) The freeze corer in action. (Right) A sample collected displaying the effectiveness of freeze coring.