The ocean is the main body of saline water, and it covers approximately 71% of the Earth’s surface by the ocean, an unbroken body of water that is usually divided into several oceans and smaller seas and rivers also. If we see the average salinity of the ocean it is around 35 parts per thousand (ppt) (3.5%), and approximately all seawater has a dissolved inorganic salt content of a body of water in the range between 30 to 38 ppt.
The main ocean is divided into the part by the continents, various reefs, and other criteria. These divisions are
- The Pacific Ocean: which separates Asia and Australia from the Americas
- The Atlantic Ocean: which separates the Americas from Eurasia and Africa
- The Indian Ocean: which washes upon southern Asia and separates Africa and Australia
- The Southern Ocean: which has no landmass separating it from other oceans and is therefore sometimes subsumed as the southern portions of the Pacific, Atlantic, and Indian Oceans.
- The Arctic Ocean: sometimes considered a sea of the Atlantic, which covers the Arctic and washes upon northern North America and Eurasia.
Origin of ocean
Origin of ocean water states as Earth combined to create from a cloud of gas and dust more than 4.5 billion years ago, an extremely large amount of lighter elements i.e. hydrogen and oxygen became closed inside the molten inside of the exciting planet formed at that time. During the initial first one to two billion years after Earth’s formation, these elemental gases emerg through thousands of miles of molten and melting rock to become active on the surface through volcanoes and fissures i.e. long narrow cracks. Inside the planet and above the surface, oxygen reacts with hydrogen to form water.
At the top of the atmosphere, where the heat unable to recovered to outer space, water vapor condensed to liquid and come down back into the water vapor layer below, cooling the layer. This atmospheric cooling process continued till the first raindrops come down to the Earth’s surface and move back into steam. This was the process of beginning rain that, with the passing of time, due to this process slowly filled the ocean basins.
Cosmic rain increases the size of one inch of water to Earth’s surface to every 10,000 to 20,000 years. This amount of water could have been sufficient to fill the oceans if these comets also known as falling star have been entering Earth’s atmosphere since the planet’s beginning 4.5 billion years ago.
Life In Ocean
Ocean evaporation, as it’s a closed process of the water cycle, is the major source of most rainfall, and ocean temperatures decide climate and wind as a guide that affects life on land. Life within the ocean developed gradually take times approx 3 billion years to life on land. Both the depth and distance from the coast impact the amount and kinds of plants and animals that live.
Physical Properties Of Ocean
The volume of the ocean is approximately 1.3 billion cubic kilometers and its area is about approximately 361.9 million square kilometers (139.7 million square miles). This can be the approx idea of a cube of water with an edge length of 1,111 kilometers (690 mi). Its average depth is 3,790 meters (12,430 ft), and its maximum depth is 10,923 meters. Nearly half of the world’s marine waters are over 3,000 meters (9,800 ft) deep. The vast expanses of deep ocean (anything below 200 meters (660 ft) cover about 66% of the Earth’s surface. This does not contain seas not connected to the World Ocean, such as the Caspian Sea.
Water has a very slight blue color that can only be seen in considerable or relatively great volumes. While the sky’s reflection does helps cause the blue appearance of the surface, we can not say that its the main reason. The primary reason is absorbed by the water molecules’ nuclei of red photons from the incoming light and reflect as blue, the only known example of color in nature resulting from vibrational, rather than electronic, dynamics.
Ocean also emits a visible glow, or luminescence, which extends for miles at night. In 2005, scientists release a formal public statement that for the first time, they had obtained photographic that they have information of this glow. It may be due to the bioluminescence process. The “milk sea” in a formed from more than two or more satellite images, and the region of the Indian Ocean off the coast of Somalia where it was discovered by the Defense Meteorological Satellite Program.
The newly released by scientists images that show a great extent of the region of the Indian Ocean, about the size of Connecticut, glowing three nights in a row. The luminescence was also marked from a ship in the area.
Scientists suspect bioluminescent bacteria are behind the phenomenon of the glow of the ocean. Such creatures produce a continuous glow, in the state of being strikingly different from something else to the brief, bright flashes of light produced by dinoflagellate‖ bioluminescent organisms that are seen more commonly lighting up ship wakes and interrupt waves.
Mesopotamian and Indo-European culture tradition, imagining the world to be covered by a closed circle of the great river. Okeanos in Greek reflects the ancient Greek observation that a strong current flowed off Gibraltar and their succeeding assumption that it was a great river. Compare also Samudra from Hindu mythology and Jörmungandr from Norse mythology. The world was assumed to be enclosed by a celestial ocean above the heavens, and an ocean of the underworld below.
The average range of ocean basin from the basins of the ocean is approximately about 6,500 feet (2,000 meters) down into the deepest trenches. Ocean basins cover about 70 percent of the total ocean area. The largest underwater mountains, for example, are higher than those on the continents. Underwater plains are admiring and more extensive than those on the continents. All basins contain certain same property as others have that include oceanic ridges, trenches, fracture zones, abyssal plains, and volcanic cones.
Mountain ranges or oceans ridges cover the ocean floor. The Mid-Atlantic Ridge, for example, start at the tip of Greenland, moves down the center of the Atlantic Ocean between the Americas on the west and Africa on the east, and ends at the southern tip of the African continent. At that point, it expands around the eastern edge of Africa, where it begins to be the Mid-Indian Ridge. That an elongated region of high barometric pressure continues eastward, making connections with other natural evaluation that eventually end along the western coastline of South and Central America. Some scientists believe that this is a single oceanic ridge that encircles Earth, one that stretches a total of more than 40,000 miles (65,000 kilometers).
Ocean ridges are formed when molten rock, or magma, form of a temporary distraction from Earth’s interior to form the seafloor, a process known as seafloor spreading. Rifts may be the identified parts of the ridges where the magma escapes.
Trenches are long, narrow, canyon-like structures, mainly found next to a continental margin. They are commonly found in the Pacific ocean than in any of the other oceans. The deepest trench on Earth is the Mariana Trench, which extends from the coast of Japan south and then west toward the Philippine Islands at a distance of approximately about 2,540 kilometers.
- The longest trench is located along the coast of Peru and Chile.
- Its total length is 5,950 kilometers
- It has a maximum depth of 8,050 meters.
- Earthquakes and volcanic activity are mostly associated with trenches.
Magma flows upward from the mantle in volcanoes to the ocean bottom not only through the break but also through numerous volcanoes and other openings in the ocean floor.
- Seamounts are submarine volcanoes and can be either active or extinct.
- Guyots are extinct volcanoes that were once above sea level but have since receded below the surface.
- As they receded, wave or current action eroded the top of the volcano to a flat surface.
The largest known seamounts are Great Meteor Seamount in the northeastern part of the Atlantic Ocean. It extends to a height of more than 1,300 feet (4,000 meters) above the ocean floor.
For Ocean layers or for Ocean zones you can read :https://aquatic4u.com/ocean-zones/