Which device is used to sample sediment from the seafloor and is known as the clamshell sampler?

• A. Clamshell Sampler
• B. Grab Sampler
• C. Box Core
• D. Push Core

Answer: (A)

Sampling seafloor sediments with a simple, quick grab relies on a mechanism that can enclose a chunk of material as it’s lifted. The clamshell sampler uses two hinged shells that close shut once it touches the seabed, trapping a piece of the surface sediment inside. It’s lowered on a cable from a ship; when it contacts the bottom, the jaws snap shut and the enclosed sediment is raised to the surface. This design is especially effective for loose, coarse sediments and for obtaining representative grab samples quickly, though it may disturb the surface and not preserve fine layering. Other devices like box cores or push cores are designed to preserve vertical stratigraphy or push into the sediment, which is different from a quick, discrete clamshell grab. So, the device described is the clamshell sampler.