The continental landscape features are reflected with analogous features on the ocean basins. Plains, Plateaus, volcanic cones, rolling hills, mountains, and valleys are found underwater in the oceans just like on land. However, research reveals that the largest mountains found beneath ocean waters are higher as compared to those on the continent. Also, the plains found under water are more extensive and flatter than those on the dry land.
The Shape of the Land
The ocean basins can be referred to that surface of the Earth that extends towards the sea from the margins of the continent. Ocean basins are usually submerged in the continent's outer edges and comprise continental slopes and shelf. Averagely, basins lie at a water depth approximated to be about 12,450 feet (Plummer, Carlson, and Hammersley 63). Then the basins drop steeply into the trenches that are deemed the deepest. The seas and oceans on earth form a water layer that covers around 71 percent of the land surface. Lots of sources comprise the margins on the continent as a portion of the ocean basins although these margins are the drowned edges of the land. They are a section of the crust that creates the continent. The shift between oceanic crust and continental crust happens on the slopes of the continent. The oceanic crust is composed of basalt whereas the continental crust mostly comprises granite (Rogers and Santosh 9). Even though, they are different in composition, both are formed from igneous rock that develops during the cooling and solidifying of magma. Basalt is formed when magma with low silica cools faster outside the continent's surface. On the other hand, granite results from magma with high silica substance that cools gradually under the Earth's surface.
The commonly known ocean basins include the Indian, Arctic, Pacific, and Atlantic Oceans. All these oceans contain primary features like abyssal, trenches, seamounts, plains and mid-ocean ridges. Conceivably, mid-ocean ridges are the most impressive features on the ocean basins as they are long and incessant volcanic mountains ranges. These high ridges indicate the section that pulls apart the oceanic crust (Rogers and Santosh 11). Then hot magma comes from under the crust and reaches forth as lava and fills the cracks that were created by the separation (Plummer, Carlson, and Hammersley 73). Later, the lava cools down and fixes to the sections of the edge forming a new ocean floor crust. The crust forms the bottom part of the oceans and is frequently generate between the mid-ocean ridges and mountain ranges that resemble seams of baseball on the seafloor (Monroe, Wicander, and Hazlett 57). This process is referred to as seafloor spreading. Extra lava is placed by multiple volcanoes which erupt alongside the ridges.
The depressions formed between the spreading parts are called rift valleys. Usually, the mid-ocean ridges are allotted into three groups depending on their rates of spreading; slow, medium as well as fast. Those ridges that slowly spread between 0.4 and 2 inches in a year are likely to have a wider and deeper central rift valley. Such Valley can be up to 6 miles wide as well as 2 miles beneath the tops or crests of the ridges, which border on either side. The mid-ocean ridges and new ocean floor are regularly being formed from rising magma from the Earth's mantle (Monroe, Wicander, and Hazlett 64). The formation of the new oceanic crust pushes crust away from the ridge in a conveyor belt fashion. (Rogers and Santosh 13). Ridges with a medium rate spread between rates of 2-4 inches per year. Valleys formed can go up to3 miles across and the depth of their range is 165-655 feet. Lastly, ridges that spread too fast go at a rate of 4-8 inches in one year. Often, their rift valley tends to be smoother in appearance as compared to those of medium and slow rates of spreading.
In most parts of the world, the mid-ocean ridges are about 6,500 feet or even below the ocean's surface. However, in some few locations, the mid-ocean ridges extend above the sea level to form an island. The common mid-ocean is the Mid-Atlantic range. It starts from Greenland and goes down to the middle of the Atlantic Ocean. The mid-ocean ridges join to create an undersea mountain system, which is well known as the mid-ocean ridge system (Plummer, Carlson, and Hammersley 79). It extends for about 40,000 miles, and it is the longest topography feature on the earth surface. The ridge system snakes between the continents encircling the planet just as the seams on a baseball. On the other hand, the seams develop an unremitting loop, a ridge system, which is offset in many areas. The breaks that are prevalent in the lines of the ridges are as a result of fractures and crack in the Earth’s crust, which rock one part and move to rock the other. Either side of the ocean crust with a fracture or fault slides towards the opposite side. This is great in alleviating tension that comes from the different segments of a mid-ocean ridge when they spread at different rates. During magmatic phases, models lead to magmatic extension by allowing the axial lithosphere to open in response to expansion (“Opportunities for Research” 28-37).
Work Cited
Monroe, James S, Reed Wicander, and Richard Hazlett. "Physical Geology: Exploring the Earth". Google Books. Belmont [u.a.: Thomson, 2006. Web. 16 Apr. 2016.
Plummer, Charles C, Diane H. Carlson, and Lisa Hammersley. Physical Geology. New York, NY: McGraw-Hill/Education, Inc, 2013. Print
"Opportunities for Research In The Geological Sciences (Book, 1983) [Worldcat.Org]". Worldcat.org. N.p., 2016. Web. 16 Apr. 2016.
Rogers, John J. W, and M Santosh. "Continents and Supercontinents (Ebook, 2004) [Worldcat.Org]". Worldcat.org. N.p., 2016. Web. 16 Apr. 2016.
