Search results
Results from the WOW.Com Content Network
The opposite of transgression is regression where the sea level falls relative to the land and exposes the former sea bottom. During the Pleistocene Ice Age, so much water was removed from the oceans and stored on land as year-round glaciers that the ocean regressed 120 m, exposing the Bering land bridge between Alaska and Asia.
As the balance shifts between the global cryosphere and hydrosphere, more of the planet's water in ice sheets means less in the oceans. At the height of the last ice age , around 18,000 years ago, the global sea level was 120 to 130 m (390-425 ft) lower than today.
The surface salinity of the ocean is a key variable in the climate system when studying the global water cycle, ocean–atmosphere exchanges and ocean circulation, all vital components transporting heat, momentum, carbon and nutrients around the world. [84] Cold water is more dense than warm water and salty water is more dense than freshwater.
The largest ocean-based source of plastic pollution is discarded fishing gear (including traps and nets), estimated to be up to 90% of plastic debris in some areas. [56] [57] Continental plastic litter enters the ocean largely through storm-water runoff, flowing into watercourses or directly discharged into coastal waters. [58]
The typical tidal range in the open ocean is about 1 metre (3 feet) – mapped in blue and green at right. Mean ranges near coasts vary from near zero to 11.7 metres (38.4 feet), [ 4 ] with the range depending on the volume of water adjacent to the coast, and the geography of the basin the water sits in. Larger bodies of water have higher ...
Stratification occurs in all ocean basins and also in other water bodies. Stratified layers are a barrier to the mixing of water, which impacts the exchange of heat, carbon, oxygen and other nutrients. [1] The surface mixed layer is the uppermost layer in the ocean and is well mixed by mechanical (wind) and thermal (convection) effects.
The eustatic sea level (from Greek εὖ eû, "good" and στάσις stásis, "standing") is the distance from the center of the Earth to the sea surface. [1] [2] An increase of the eustatic sea level can be generated by decreasing glaciation, increasing spreading rates of the mid-ocean ridges or increasing the number of mid-oceanic ridges.
Water carried into the mantle eventually returns to the surface in eruptions at mid-ocean ridges and hotspots. [131]: 646 Estimates of the amount of water in the mantle range from 1 ⁄ 4 to 4 times the water in the ocean. [131]: 630–634 The deep carbon cycle is the movement of carbon through the Earth's mantle and core.