The Earth System Lithosphere Biosphere Hydrosphere and Atmosphere

The Earth System: Lithosphere, Biosphere Hydrosphere, and Atmosphere

This Island Earth About 4. 5 billion years old As far as life is concerned: “Goldilocks of the Solar System” (relative to Sun, not too far, not too close, just right !)

Earth’s Four Spheres 1. Lithosphere n 2. Atmosphere n 3. Hydrosphere n 4. Biosphere n

The Earth’s Four Spheres

Lithosphere: comprises the solid Earth and includes both Earth’s surface and the various layers of the Earth's interior. n 94 % percent of the earth is composed of the elements oxygen, iron, silicon, and magnesium n

Earth’s Layers: Composition and Mechanical Characteristics

ATMOSPHERE • This is the gaseous envelope that surrounds the Earth and is the transition between its surface and the vacuum of space • consists of a mixture of gases composed primarily of nitrogen, oxygen, carbon dioxide, and water vapour

Atmospheric structure exosphere Satellites and space shuttle orbit in the upper themosphere Auroras in lower troposphere Many meteors burn up here Majority of atmospheric mass here

HYDROSPHERE n n This includes all water on Earth (including surface water and groundwater) Liquid water on Earth makes it distinct from other bodies in the solar system

Subcomponents of hydrosphere are connected via the hydrologic cycle

BIOSPHERE This includes all living organisms, and all organic matter that has not yet decomposed. n Plants, animals, bacteria, viruses, fungi, everything that is or was alive. n

BIOSPHERE n n Life began at least 3. 5 billion years ago and The biosphere makes our planet different from all others (as far as we know) It is structured into a system known as the food chain whereby all life is dependent upon the plants that are capable of photosynthesis. Food chain is more realistically viewed as a web

Food Web Note that interactions within even a single ecosystem are very complex !