Oceanbotten

Oceanbotten refers to the seabed, the solid surface that forms the bottom of the oceans. It includes the sediment layer and the underlying bedrock, spanning from the shallow continental shelf to the deepest ocean trenches. The seabed is dynamic, influenced by ocean currents, sediment supply, tectonic activity, and biological processes.

The seabed is composed of sediments deposited over the oceanic crust and continental margins. Sediments are a mix of terrigenous material from land, pelagic sediments derived from the remains of microscopic organisms, and biogenic carbonates. In geologically active regions, bedrock is exposed in fracture zones; at other sites, thick sediment columns cover the crust.

The seabed features include continental shelves, slopes, rises, abyssal plains, mid-ocean ridges, seamounts, guyots, trenches. Hydrothermal vents and cold seeps occur in tectonically active areas.

Benthic organisms inhabit the seabed, and community composition varies with depth, substrate, oxygen, and organic matter supply. Microbial communities drive chemosynthesis near vents; macrofauna include worms, crustaceans, and echinoderms. The seabed stores carbon and participates in nutrient cycling, with oxygen minimum zones affecting deeper layers.

The seabed hosts hydrocarbon resources and potentially minerals such as nodules; exploration and mining pose ecological risks. Mapping and monitoring use sonar, submersibles, and remotely operated vehicles. Conservation measures include protection of seabed habitats and sustainable management.

Seabed mapping supports navigation, climate science, and ecology; international efforts produce bathymetric charts and habitat maps.