Describe the major topographic features of the ocean basin floor - Research Paper Example

it is these basins that are of most interest when studying the topology of the ocean floor, as they differ greatly from the features of the surrounding landmasses (Garrison, Oceanography). This essay will briefly discuss several types of the features of the deep ocean basins and some of their implications for the science and study of oceanography. These features are primarily related to various effects of tectonic plate shifting. A significant portion of the ocean floor is categorized as the abyssal plain, which are large and mostly flat areas, covered in oceanic sediment (Garrison, Oceanography).

In fact, the abyssal plain covers the largest proportion of the Earth's surface, more than any other known geographical feature (Garrison, Essentials of oceanography). The abyssal plain is the portion of the seabed found at the bottom of the ocean basins, in the absence of other features or tectonic activity. They may sometimes contain areas of abyssal hills, which are formed through low-level volcanic activity (Karleskint). The seafloor has numerous geological structures that rise up out of this abyssal plain, most of which are also volcanic in nature.

One of these is seamounts, which are volcanic protrusions from the ocean bed taller than 100 meters from base to summit (Wessel, Sandwell, & Kim). These make up approximately 5% of the known area of the ocean floor (Yesson et al.). Seamounts can be active or extinct, and play a myriad of roles in the ocean ecosystem and the flow of surrounding water (Wessel, Sandwell, & Kim). Another are knolls, which are similar to seamounts in origin, but are smaller and do not have such a large effect on the surrounding ocean.

These make up approximately 16% of the ocean floor habitat. Tens of thousands of such seamounts and knolls exist on the ocean floor, many of them still unmapped or even undiscovered; the ones that are known are biased towards areas with heavier ship activity and so such proportions may be considerably different from the actual makeup of the rest of the ocean basin (Yesson et al.). Larger volcanic structures may even be exposed above the surface of the ocean water, and result in chains of volcanic islands (Garrison, Oceanography).

These chains, and many other volcanic bathygraphic features, are generally found along the boundaries of the tectonic plates making up the Earth's crust. Island chains may also be found along the borders of deep ocean trenches, another feature of the seabed. This type of island chain is referred to as an island arc (Karleskint). Rugged oceanic ridges are another feature of the deep ocean floor, appearing in areas where the ocean floor is spreading due to a divergent plate boundary. The area where the highest volcanic activity is found is called the rift valley, and the locations where new ocean floor is being formed due to such activity are referred to as the rift zones.

These rift areas are often home to vibrant communities of deep-sea ocean life, unlike the ecosystem seen on the relatively lifeless abyssal plain (Karleskint). These communities exist as a result of the hydrothermal vents, or springs of hot water, produced by these zones (Garrison, Essentials of oceanography). Ocean ridges are also usually accompanied by fracture zones, which run perpendicular to the direction of the ridges. (Karleskint). The