Oceans (Explore)The last erosion in this aspect is ocean. In the ocean, light and temperature decrease with depth, and pressure increases. Continental shelf will be seen in the ocean if the water was drained away. Continental shelf is a gently sloping plain that forms an apron of shallow water along the edges of most continents. Beyond the continental shelf, the continental slope descends more steeply to the floor of the deep ocean.
Ocean currents are the patterns of flow in Earth's oceans. Ocean currents are affected by winds, Earth's rotation, and the positions and shapes of the continents. A surface current is a large stream of ocean water that moves continuously in about the same path. Winds blowing across the surface of the ocean cause the continuous flow of surface currents. The deep ocean currents are caused by differences in the density of ocean water. Colder temperatures or higher salinity (the proportion of dissolved salts in water) water is more dense. Density currents are responsible for a slow mixing of water between the surface and deeper ocean. Upwelling is the movement of water from the deep ocean to the surface. 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. This process can also be referred to convection that we talked about. Convection is the evidence that this aspect is also related to the Sun's energy. |
Two physical processes, hydraulic action and abrasion, are responsible for much wave erosion.
Hydraulic Action |
Hydraulic action occurs when waves pound on cracks in rocks. Waves fill a crack, which increase the pressure, just like the mechanical weathering. Waves also compress air into the crack, which increase the pressure. Eventually, the rock breaks into smaller pieces. This process continues and create many different landforms.
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Longshore Drift |
Longshore drift is the process that moves sand along a shore in a zig-zag motion. Also, slowed down currents deposit sediment in a process called spit.
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This is the end for Aspect 2, the Earth's surface. Next aspect will be about the interior of Earth!