Erosion is the natural and chemical process by which the surface of the earth is constantly being carved and shaped by water, wind, heat, cold, gases and plants.
Geological forces account for the erosion of the surface layers of rocks.
As these surfaces come in contact with rain and wind, or expand from the heat of the sun, fragmented pieces break away. These pieces of fragmented rocks are carried away by rain or wind. Rivers are carved out of rock as rain water meanders down the face of a mountain, searching for the path of least resistance. Rain dissolves some minerals and can destroy others. When water seeps into the cracks of rocks and freezes, this expansion can cause the rock to crack. Roots of plants, such as trees, can also split a rock.
The waves and currents of the ocean are instrumental in sculpturing the cliffs and beaches of the coastal areas. During severe weather coastal erosion may cause some serious damage.
The erosion of soil has been accelerated by the activities of humans. Lumbering, agriculture, and housing developments have removed much of the vegetation which would have protected the soil from the effects of erosion. With this mantle of greenery in place, the effects of erosion would have been greatly impeded as plants would have acted as windbreakers preventing the wind from carrying away the soil, while the roots would prevent the soil from being carried away by the water.
Ocean Currents & Waves
Ocean currents are like rivers flowing through the ocean. Unlike true rivers, which meander over the land, and are bound by mud, stone, or sand, the ocean currents are bound by other currents or the boundaries of the continents. The major cold water currents flow towards the equator. Warm water currents, which are found mainly at the surface of the ocean as a result of solar heating, begin near the equator and move northward towards the Arctic Circle
The Gulf Stream
The Gulf Stream is a river whose path flows through the ocean. The path of the Gulf Stream is longer than that of the Amazon River and the currents produced are stronger than those of the Mississippi River.
Like any river, the Gulf Stream has its tributaries. These tributaries flow through the Gulf of Mexico, the Caribbean Sea, and around the coast of Cuba. The current continues southeastward along the coast of the United States and then carouses northeast across the Atlantic Ocean up to the British Isles where it then moves toward the Arctic Circle.
Winds blowing across the surface of the ocean currents are called the westerlies or trade winds. these winds blow towards Europe and are warmed by the waters of the Gulf Stream. This warm air helps to temper the climate of western Europe.
Currents can run swift and deep and can be virtually undetected by the human eye. This is why it is important to observe the rules of water safety when boating, fishing, or swimming. Each year rapidly moving currents are responsible for the drowning deaths of many individuals.
Tides & Waves
Gravity pulls at the ocean waters causing them to bulge towards the moon. As the moon travels around the earth, this watery bulge strains to follow its path, resulting in high and low tides. Extremes in tides occur when the sun and the moon are aligned and the gravitational pull of the sun reinforces that of the moon.
Waves are formed as the wind rushes over the water. The increased velocity of the wind creates larger and larger waves. Tidal waves are not powered by the wind but instead are the result of underwater volcanic activity, avalanches, or earthquakes. Tidal waves can strike the coast with a terrifying force causing much destruction of property and loss of life.