dense overflow

A density current is a flow within a liquid or gas driven by gravity due to differences in density. These density variations can arise from differences in temperature, salinity, or suspended sediment concentration.1

In oceans and lakes, density currents occur when water is colder, saltier, or contains more sediment, making it denser. This denser water sinks and flows along the bottom, maintaining its flow for a considerable distance due to slower mixing with overlying waters.1

"Dense overflows" are a type of density current originating from marginal seas or high latitudes. They form where water becomes exceptionally dense due to cold temperatures and high salinity (from ice formation) or high temperatures and salinity (from evaporation). This dense water then flows downslope, sometimes through constrictions like straits, into deeper ocean basins. Examples include overflows from the Mediterranean Sea and the Denmark Strait, which contribute to deep ocean circulation.1

Turbidity currents are a specific type of density current where suspended sediments increase the water's density, often triggered by underwater landslides or earthquakes.1