Water in Nature: Oceans, Rivers, and the Water Cycle
Water in Nature
Saltwater: Oceans and Seas
Most of the planet’s water (97.21%) is saltwater found in seas and oceans.
- An ocean is a vast body of water separating continents. The major oceans are the Pacific, Atlantic, and Indian Oceans. Together, they form the Southern Ocean surrounding Antarctica. The Pacific and North Atlantic connect to form the Arctic Ocean.
- Seas are extensions of the oceans closer to continents, like the Cantabrian Sea or the Caribbean Sea, which are part of the Atlantic Ocean.
Glossary of Climate and Environmental Terms
Anticyclone
A zone of high atmospheric pressure surrounded by a series of isobars, where pressure decreases from the center outwards. It is marked on a weather map with an ‘A’. An anticyclone is formed when a mass of cold, dense air located at a certain height descends, increasing the pressure in that area.
Dryness
Although it can coincide with periods of no rain, dryness occurs when evapotranspiration is greater than total precipitation. This means the land loses more water to the atmosphere than
Read MoreEarth’s Movements, Relief, and Climate
Movement of the Earth
The Earth is a planet in constant motion as it travels through space. Two of its most important movements are rotation and translation.
Rotation Movement
Rotation is the movement where the Earth spins counterclockwise on an imaginary line called the axis of rotation, which passes through the poles. This rotation takes 24 hours and results in the sequence of days and nights. When the sun’s rays hit a part of the Earth’s surface, that area is illuminated, and the temperature increases,
Read MoreSoil Erosion, Desertification, Deforestation, and Waste Management
Soil as a Vital Medium: Erosion and Pollution
Soil plays a vital ecological role, providing a substrate for plants and essential mineral elements. It’s a habitat for microorganisms that detoxify waste and convert it into plant nutrients, and a crucial reservoir for biogeochemical cycles.
Soil erosion, the loss of nutrient-rich topsoil by wind or rain, is exacerbated by reduced vegetation. This loss weakens the soil structure, making it more susceptible to further erosion.
Soil contamination is critical,
Read MoreEarth’s Formation, Interior, and Plate Tectonics
Earth’s Formation and Early Characteristics
Formation of Earth and Solar System (4.6 Billion Years Ago)
The Earth and solar system originated from a nebula, a swirling cloud of gas and dust. As the nebula spun faster, hydrogen concentrated at the center, forming the Sun.
The accretion theory proposes that remaining nebula materials formed planetesimals, varied rocks floating in space. Collisions between planetesimals created a molten mass of rocks, the primitive Earth.
As the molten Earth rotated,
Read MoreGeological Evolution of the Iberian Peninsula
The Plateau
An elevated plain at 600-800 m, formed by the erosion of the Hesperian Massif. It was reshaped by the Alpine orogeny, creating three distinct units:
a) The Former Paleozoic Base
Located west of the peninsula, erosion exposed raw materials like granite, slate, and quartzite. The relief is primarily peneplain, with occasional residual mountains. Rivers crossing the plateau have carved deep gorges.
b) The Mountain Ranges of the Plateau
Formed during the Tertiary period by the Alpine orogeny.
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