SEDL / STP / STP1442-EB / STP11551S

Deep-Freeze Sampling Methods for Soft Sediments

Ricking, M
Free University of Berlin, Berlin,

Schulze, T
Free University of Berlin, Berlin,

Pages: 7    Published: Jan 2003

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Abstract

Freeze coring systems were applied for sampling high-water-content sediments or very coarse sediments for a couple of years. At the Free University within the last 20 years different systems were developed and applied for sampling the upper 1.5–2.5 m in an undisturbed stratified way. The difficulty in controlling the depth penetration has been overcome by applying a small echo sounding system onboard. The LINDE-LANCE device runs on liquid nitrogen pressurized through a copper pipe, where the sediment freezes in concentric layers onto the lance at -193°C. A low weight system with a closed aluminium lance (CO²-LANCE) running on a eutectic mixture of dry ice and alcohol that freezes the concentric sediment layers onto the lance at -90°C was developed for a much easier sampling by means of a Zodiac. Advantages and limits are addressed.