Earth's Climate, Greenhouse Effect, and Internal Structure

Greenhouse Gases and Earth's Climate

Greenhouse gases allow transparent solar radiation to pass through, but they are opaque to infrared radiation emitted by our planet.

The Greenhouse Effect

The greenhouse effect raises the temperature of the atmosphere near the Earth's surface. This is due to the difficulty of heat dissipation, caused by the presence of carbon oxides from industrial combustion. Is it harmful to life on Earth?

Origin of the Wind

Winds are caused by the Earth's rotation and differences in solar radiation, mainly longwave radiation, which is absorbed indirectly through the atmosphere.

Earth's Surface and Water

The presence of an atmosphere with greenhouse gases prevents the freezing of the hydrosphere.

Dynamic System: Atmosphere and Hydrosphere

After millions of years of erosion, why isn't the land perfectly flat? The answer lies inside the Earth.

Exploring the Earth's Interior

Seismic waves indicate changes in the Earth's structure and inform us about its physical properties.

Internal Structure of the Earth

• Lower Mantle
• Upper Mantle
• Inner Core
• Outer Core

Discontinuities

• Mohorovicic Discontinuity: Establishes the separation between crust and mantle.
• Wiechert-Gutenberg Discontinuity: S waves do not spread, and P waves sharply reduce speed, establishing the separation between mantle and outer core.
• Lehman Discontinuity: P waves increase speed in the almost totally solid inner core.

Internal Energy of the Earth

The nucleus is the source of the Earth's internal energy.

Wegener's Theory of Continental Drift

Wegener provided evidence for his theory of continental drift:

• Geographic Evidence: The continents could fit together.
• Paleontological Evidence: Similar fossils were found in past continents.
• Geological and Tectonic Evidence: Rock types showed physical continuity.
• Paleoclimate Evidence: Climates did not coincide with those of the past.

Representing Internal Energy

Internal energy is represented by heat, not only in the form of earthquakes.

Oceanic Ridges

At oceanic ridges, volcanic material emerges from the Earth's interior, adding to the ocean lithosphere and expanding it. This is how the Americas, Africa, and Europe separated.

Extracting the Lithospheric Plates

Convection flows in the mantle cause the lithosphere to break into plates.

Plate Movements and Consequences

Plate collisions generate orogenic continental borders, such as the Andes, or intra-continental mountains, such as the Himalayas. In these zones, the oceanic lithosphere is destroyed by subduction.

This process produces the formation of continents and supercontinents, or isolates them, opening new oceans.

Relief and Destruction

Gradual erosion flattens the crust, creating plains.

History of the Earth

1. The Earth is a hot rock field.
2. An object collided with Earth, forming the lava.
3. Formation of the first seas and continents.
4. Almost global glaciation.
5. Formation of the last Pangea.
6. New continents.