|Corer||Sample Footprint||Max Length of Sample*||Approximate Coring Device Weight|
|MARSSAM Gravity Corer||10.16 cm diameter||6 m||600 lbs|
|MARSSAM Giant Gravity Corer||10.16 cm diameter||12 m||3500 – 6000 lbs|
|Benthos Gravity Corer||6.68 cm diameter||3 m|
|Kasten Corer (large)||20 cm x 20 cm||4 m||3500 – 6000 lbs|
|Kasten Corer (small)||14 cm x 14 cm||3 m|
Gravity cores are lowered directly into the seafloor, relying on their own momentum to penetrate the sediments. A one way valve attached to the top of core liner acts as the proverbial “finger on the straw”, allowing water to pass through as the corer penetrates the seafloor, and providing suction to hold the sediments in on the way back to surface.
Kasten cores function in the same manner as a gravity core, except that they are rectangular in profile. One side of the coring box is detachable, providing access to the sediments. MARSSAM has two sizes of Kasten cores, the larger of two uses the same core weight as the jumbo piston core and giant gravity core and has a stainless steel liner inside of a galvanized sampling box; the smaller of the two consists of a stainless steel sampling box attached to a valved core weight.