Earth Science: Earth – Islands and Atolls Earth’s largest island is Greenland, with an area of over 830,000 square miles. The smallest islands are just dots in the ocean. Many islands are part of a continent; others owe their existence to volcanic eruptions. Islands are categorized into continental and oceanic islands. Continental or shelf islands were … Read more
Earth Science: Earth – Water – Oceanic Crust Oceanic crust covers two-thirds of the Earth’s surface. Crustal rocks are relatively recent, with none older than 200 million years, and they are constantly in motion. This movement expands the oceans and shifts entire continents. The oceanic crust begins beyond the flooded part of the continental shelf. … Read more
Earth Science: Tides, Coasts, and Waves The continental coastline of the Earth is about 250,000 miles (440,000 km) long. But the area of transition between the ocean and land is constantly changing due to the tides and surge. Coastal landscapes are shaped over time by the destructive forces of the seas that slowly but steadily … Read more
Earth Science: Oceans – Ocean Currents Ocean currents, dependent upon the winds and varying salt concentrations, drive huge masses of water over long distances. Numerous surface and deepwater currents act as giant conveyer belts, circulating the water in the world’s oceans. The Earth’s ocean waters can complete a turnover in a few hundred years, though … Read more
Earth Science: Oceans – Physical Characteristics Seawater may appear to the naked eye as if it were a uniform substance. However, oceans are complex environments with varying salt and nutrient contents, as well as different pressures, temperatures, and light conditions. Different substances are continuously washed into the oceans from rivers, melting snow, precipitation, and wind. … Read more
Earth Science: Water – Oceans More than two-thirds of the Earth’s surface is covered in water. The ocean is the largest and oldest habitat on our planet and plays a central role in shaping the climate. It provides energy, natural resources, and one of the major food sources for humans. Nevertheless, large parts of the … Read more
Earth Science: Water on the Earth The name of our planet may not be the most appropriate since only 29 percent of the Earth’s surface consists of land, while 71 percent is covered by water. Composed of two hydrogen atoms and one oxygen atom, water is one of the most important resources on Earth and … Read more
Earth Science: Origins and Geology – Mass Movements Avalanches, earthflows, and rockfalls: all over the Earth where the angle of the natural ground slope is exceeded, gravity makes itself felt and starts to flatten, carry away, and level the landscape. Massive ground movements belong to the processes of large-scale erosion or denudation. This term incorporates … Read more
Earth Science: Origins and Geology – Deposition The surface of the Earth undergoes constant change. In this never-ending process, forces created by wind, water, or glacial ice erode the land in one place and deposit it elsewhere due to the pull of gravity. Rivers transport loose particles and debris, and new land is created where … Read more
Earth Science: Changing Earth – Erosion Once rocks reach the surface of the Earth they begin to disintegrate, and can be carried away as rubble to be deposited elsewhere. All processes that contribute to this leveling of the Earth’s surface are termed erosion. Water is a significant erosive power. When precipitation falls on areas with … Read more
