Earth's Dynamic Systems: Motions, Spheres, and Climate

Earth's Fundamental Motions

Two Primary Earth Movements

• Rotation: The spinning of Earth on its axis. Consequences: Day and night cycle, Coriolis effect.
• Revolution: The orbiting of Earth around the Sun. Consequences: Seasons, varying daylight hours.

Earth's Interconnected Spheres

The Four Spheres of Earth

• Atmosphere: The layer of gases surrounding Earth. It provides air for breathing and protects from harmful solar radiation.
• Hydrosphere: All water on Earth, including oceans, rivers, lakes, and glaciers. It plays a key role in the water cycle and supports aquatic life.
• Lithosphere: The rigid outer layer of Earth, consisting of the crust and upper mantle. It forms landmasses and ocean floors.
• Biosphere: All living organisms and their interactions with the other spheres. It includes ecosystems and supports life on Earth.

Interrelation of Earth's Spheres

These spheres interact continuously, influencing climate, weather patterns, and sustaining life on Earth.

The Lithosphere: Earth's Solid Outer Layer

Definition of the Lithosphere

The solid, outer part of the Earth, including the crust and upper mantle.

Tectonic Plate Movements and Boundaries

• Divergent Boundaries: Plates move apart. Causes: Mid-ocean ridges, rift valleys.
• Convergent Boundaries: Plates move towards each other. Causes: Mountain formation, subduction zones.
• Transform Boundaries: Plates slide past each other. Causes: Earthquakes.

Seismicity, Volcanism, and Landform Formation

• Seismicity: Earthquakes occur due to the movement of tectonic plates.
• Volcanism: Volcanic activity occurs at convergent and divergent boundaries.
• Landform Formation: Mountains, valleys, and other features form due to tectonic activity and erosion.

The Hydrosphere: Earth's Water Systems

Definition of the Hydrosphere

All the water on Earth in various forms.

The Water Cycle

Processes include evaporation, condensation, precipitation, and runoff.

Divisions of the Hydrosphere

• Continental Waters: Rivers, lakes, glaciers. Elements: Freshwater ecosystems.
• Oceanic Waters: Oceans, seas. Elements: Marine ecosystems.

The Atmosphere: Earth's Protective Gas Layer

Importance of the Atmosphere

Protects from harmful solar radiation, provides oxygen, and regulates temperature.

Weather Versus Climate

• Weather: Short-term atmospheric conditions.
• Climate: Long-term patterns of weather in a region.

Understanding Climate

Factors Influencing Climate

• Latitude
• Altitude
• Proximity to water bodies
• Ocean currents

Microclimate Explained

A local atmospheric zone where the climate differs from the surrounding area.

Climate Change

Historical Factors of Climate Change

• Volcanic eruptions
• Solar radiation changes
• Natural greenhouse gas variations

Global Warming

• Difference from Climate Change: Specific to the increase in Earth’s average surface temperature.
• Causes: Greenhouse gas emissions, deforestation.
• Effects: Rising sea levels, extreme weather events, loss of biodiversity.