Continental shelf
Ocean water is a mixture of dissolved salt and gasses. Salinity is the proportion of dissolved salt in water. 35 grams of salt is in a kilogram of ocean water. Rain dissolves salt from the surface of rocks and the river carries them to the ocean. Volcanic eruptions send elements such as sulfur and chlorine to the atmosphere and ocean. Animals and plants removes salt out of the sea and also by deposition.
Light and temperature decreases with depth, whereas pressure increases. Light cannot penetrate deeper than 200m. The top 100m to 500m are well mixed and warm in the temperate and equatorial zones. Deeper the water is much cooler and denser. At depth of 500m, pressure is 50 times greater than the atmospheric pressure at sea level.
Continental shelf is a gently sloping plain that forms an apron of shallow water along the edges of a continent. Beyond this there is a continental slope which descends steeply into the deep ocean. The ocean floor itself is a vast, flat plain dotted with volcanic peaks. The deepest point in the ocean is the Mariana Trench, more than 11 km below sea level.
Density Currents
Surface current is a large stream of ocean water that continuously in the same path. Winds blowing across the surface d the ocean cause the continuous flow of surface currents. Global surface currents reflect the wind patterns of the atmosphere. Currents with warm water flows from the equator along the east side and the currents of cold water flow away from the pole along the west side.
Deep ocean currents are caused by differences in the density of ocean water. Since deep ocean currents are affected by density, they are called density currents. Density currents slowly mixes the water between the surface and deeper ocean.
The movement of water from the deep ocean to the surface is called upwelling. In upwelling, winds blow warm surface water aside. This allows cold water from the deep ocean to rise and take the place of the warmer water. currents and wind pull surface water of both side into the pole. Upwelling occurs in the strip where surface currents move apart.Areas of upwelling support large populations of fishes and whales.
Deep ocean currents are caused by differences in the density of ocean water. Since deep ocean currents are affected by density, they are called density currents. Density currents slowly mixes the water between the surface and deeper ocean.
The movement of water from the deep ocean to the surface is called upwelling. In upwelling, winds blow warm surface water aside. This allows cold water from the deep ocean to rise and take the place of the warmer water. currents and wind pull surface water of both side into the pole. Upwelling occurs in the strip where surface currents move apart.Areas of upwelling support large populations of fishes and whales.
Hydraulic erosion
On rocky coasts, wave erosion creates cliffs, arches, caves, and tall rock towers called sea stacks. Two physical processes, hydraulic action and abrasion, are responsible for much wave erosion.
Hydraulic erosions occur when wave pounds on cracks in rocks. Wave fills a crack with water then before the water drains, another wave forces more water into the crack putting more pressure. Waves also compresses air as they slam into the crack which contribute to wave erosion. Abrasion also breaks rock rubbing away the rocks by sediment carried by waves. Longshore drift is the process that moves sand along the shore. Waves carrying sediment sediment approaches the shore and as the wave break, they carry sand up the beach. The water and sand then flows directly back which makes longshore drifts produce a zigzag motion that moves sand a great distance.
Currents and waves deposit sediment in bays and inlets and overtime sediment can collect along the shore. Rivers that discharges into the ocean are the main source of sand in oceans. When currents meet a bend in the shoreline, they slow down and deposit sediment, this sediment is called spit.
Hydraulic erosions occur when wave pounds on cracks in rocks. Wave fills a crack with water then before the water drains, another wave forces more water into the crack putting more pressure. Waves also compresses air as they slam into the crack which contribute to wave erosion. Abrasion also breaks rock rubbing away the rocks by sediment carried by waves. Longshore drift is the process that moves sand along the shore. Waves carrying sediment sediment approaches the shore and as the wave break, they carry sand up the beach. The water and sand then flows directly back which makes longshore drifts produce a zigzag motion that moves sand a great distance.
Currents and waves deposit sediment in bays and inlets and overtime sediment can collect along the shore. Rivers that discharges into the ocean are the main source of sand in oceans. When currents meet a bend in the shoreline, they slow down and deposit sediment, this sediment is called spit.