ABSTRACT
The most common form of seabed corer is the UMEL Sargent gravity corer. Another gravity corer in fairly widespread use is the Kullenberg gravity corer. A typical example of the former unit, shown in Figure 4.1,1 is 58 in. long. The bottom section is a 3 ft or 6 ft barrel with a core cutter at the bottom. The body of the corer has a weight locking clamp at the top and a maximum total of twelve 75 lb lead weights can be added to the body. The barrel has a plastic tube inserted with the core cutter at the bottom. The corer is usually deployed from a chute and suspended about 15 ft above the sea floor. A trip mechanism is initiated and the corer falls to the sea floor. The core cutter penetrates the sea floor and the weight of the corer is hopefully sufficient to drive the corer deep into the sea floor, producing a sample which is forced up into a plastic tube inserted inside the core barrel. The plastic tube is removed with the core sample in place. Other corers in use include the Benthos gravity corer. A grab bucket is sometimes used in place of the gravity corer. A van Steen grab bucket is typical.
