Gulf of Mexico Data Atlas Gulf of Mexico Data Atlas

Marine Geology

Dominant Bottom Types and Habitats

This map provides a summary of bottom types and bottom habitats in the Gulf of Mexico. The sediment characteristics are described as follows: if the most abundant of the seabed-sized fractions of rock, gravel, sand, or mud is >66%, then it is said to be dominant. If the most abundant of these is >33%, then it is subdominant. If one of the four -rock, gravel, sand, or mud- is the more dominant in an area, then strong control is exerted over the types of organisms (benthos) that live on the ocean floor. Rock and gravel provide microhabitats for organisms and favor attached epibenthos (e.g., suspension feeders). However, rock is more stable. Sand is the most mobile of substrates and encourages vagrant and active burrowing forms. Mud is usually stable on the scale of burrows because of its cohesiveness and favors infauna. It also tends to have the highest organic carbon contents. The data for this analysis comes from a subset of USGS's usSEABED called dbSEABED.

Additional image formats and visualization tools:

Dominant Bottom Types and Habitats Atlas Dataset

Seabed Sediment Folk Codes

This map provides an overview of the loose sediment types in the Gulf and is a guide to their mobility under waves and currents, as well as to the physical factors for benthic animals. Sediment can be classified in a variety of ways. One method, known as the Folk Codes (Folk, 1974) divides sediments into mud, gravel and sand, depending on how big the particles are. Sand, coarse mud (silt), and fluid muds are unstable in areas affected by waves and currents. Gravel and stiff mud are unstable only in extreme weather conditions. Muddy bottom areas on slopes of 2° or more are prone to sliding and mass failure caused by gravity and internal sediment pore-water pressures. The data for this analysis comes from a subset of USGS's usSEABED called dbSEABED.

Additional image formats and visualization tools:

Seabed Sediment Folk Codes Atlas Dataset

Seafloor Geomorphology

This map shows geomorphological features of the seafloor in the Gulf of Mexico such as escarpments, canyons, and seamounts. There are layers showing basic zones of the seafloor based on depth: shelf, slope, abyss, and hadal. Also, the abyssal and shelf zones were classified into subtypes.

Additional image formats and visualization tools:

Seafloor Geomorphology Atlas Dataset