Earth's Physical Geography: Tectonics, Water, and Climate

Tectonic Theory

The Earth's crust is formed by several tectonic plates moving slowly. These plates separate, overlap, and collide, creating new forms of relief.

Volcanoes

Openings in the crust through which hot material from inside the ground reaches the surface.

Earthquakes

Ground shaking caused by the fracture and displacement of rocks. When occurring in the sea, they can trigger tsunamis, which are capable of destroying everything in their path.

Landforms

• Mountains: Elevations with high slopes. Isolated peaks are called hills, while grouped or jagged formations are known as mountain ranges.
• Highlands: Extensive flat or slightly inclined surfaces located at a certain altitude above sea level.
• Plains: Large flat or gently undulating surfaces at a low altitude relative to sea level.
• Depressions: Sunken areas that are lower than the surrounding land.

Water Resources

Water covers over 70% of the Earth's surface. Of this, 2.5% is freshwater, with only 0.25% found in lakes, rivers, and underground reservoirs; the rest is frozen.

Oceans

Large bodies of saltwater with constant currents. When a current's temperature is higher than the surrounding water, it is a warm current; otherwise, it is cold. These currents significantly affect climate and biological productivity.

Rivers

Continuous freshwater flows that empty into the sea or other rivers. River flow is considered regular if the volume is maintained, or irregular if the volume fluctuates significantly.

Lakes

Permanent, closed bodies of water.

Groundwater

Almost 25% of the Earth's freshwater is found beneath the surface, serving as the main potable water reserve. Underground water flows are known as subterranean rivers, and deposits are called aquifers.

Climatic Zones

Warm Climates

• Equatorial: Warm with abundant precipitation (over 2000mm annually).
• Tropical: Warm with precipitation concentrated in specific months.
• Desert: High temperatures with scarce precipitation.

Temperate Climates

• Mediterranean: Mild and warm temperatures.
• Oceanic: Mild temperatures with abundant precipitation throughout the year.
• Continental: Extreme temperature variations between cold and hot seasons with humidity.

Cold Climates

• Polar: Very low temperatures and scarce precipitation.
• High Mountain: Cold temperatures with high precipitation.

Atmosphere

The layer surrounding the Earth that absorbs a portion of the sun's rays while reflecting others back into space. It maintains an average temperature of 15°C, though without it, the temperature would drop to -18°C.