Ocean

Currents

A current is a body of water that is moving in a certain direction through a surrounding body of water in which there is less movement. These can develop throughout the ocean and there are two that can influence their formation. These are seawater temperature and the amount of salt in seawater/ salinity.

Starting off with seawater temperature, while the Ocean is one giant body of water, it is not the same throughout. One difference is the temperature, caused by the suns unequal heating of the earths surface. This results in water near lower latitudes to be warmer and water at higher latitudes to be colder. Colder water is dense, leading to it sinking while warmer water is less dense, leading to it floating.

The other factor that effects the development of currents is salinity. Ocean water contains salt and salt content affects whether the water sinks or floats. The more salt in water, the more dense it will be and the more likely it will sink. Some factors that can affect how much salt there is in the water are evaporation and precipitation. Evaporation removes fresh water, leaving the salt, and therefore making the water more dense. Precipitation rains fresh water, lowering the salt contents, and making the water less dense.

The Geosphere

As you move farther and farther away from the continents, there are various landforms at the bottom of the ocean. The first which is also closest to the continents is know as the continental shelf. These start at the shore and can go as far as 10m to 1000's of km. They are also the shallowest part of the ocean, usually not reaching more than a hundred meters.

Once this section ends, the ocean floor starts to slope much farther downwards, known as the continental slope. The slopes are covered by mud and silt, but they frequently slide downwards to the base of the slope. The continental rise is at the base of the continental slope, and is mainly made up of mud, silt, and other sediments that slid off of the slope. The continental margin is the continental shelf, slope and rise together. Following the continental margin are the abyssal plains. These are considered the deep ocean, and are generally 4-5km below the surface. Also near the plains are abyssal hills, which are rock formations that can rise as far a 900m above the plains. Abyssal hills and plains cover the majority of the ocean, up to 3 quarters.