EARTH AS A SYSTEMSection1- Earth: A Unique Planet

Section 2- Energy in the Earth System

Section 3- Ecology

Earth Basics

Third Planet from the sun Made mostly of rock ~71% of Earth’s surface covered by

water Global ocean

Oblate Spheroid

Earth’s Interior

3 major compositional zones 5 major structural zones

Compositional Zones of Earth’s Interior

Crust Mantle Core

Structural Zones of Earth’s Interior

Lithosphere Asthenosphere Mesosphere

Earth as a Magnet

Two magnetic poles North and South

Extends beyond the atmosphere Affects the Magnetosphere

Earth’s Gravity

Gravity Isaac Newton Law of gravitation

Weight and Mass

Weight is a measure of the strength of the pull of gravity on an object

Mass of an object does not change with location, but the weight of an object does

Weight and Location

Weight varies according to location on Earth’s location on Earth’s surface

Section 2Energy in the Earth System

• System• The operation of the Earth’s system is a result

of interaction between two most basic components of the universe Matter Energy

Closed and Open Systems

Closed- A system in which energy, but not matter, is exchanged with the surroundings

Open- A system in which both energy and matter are exchanged with the surroundings

The Earth System

Open However, very limited amounts of matter are

exchanged

Earth’s 4 Spheres

Matter on Earth is in solid, liquid, and gaseous states

4 spheres that are storehouses of all of the planet’s matter are: Atmosphere Hydrosphere Geosphere Biosphere

Earth’s Energy Budget

First Law of Thermodynamics Energy is transferred between systems

It cannot be created or destroyed Second Law of Thermodynamics

When energy transfer takes place, matter becomes less organized with time

Internal and External Sources of Energy

Earth’s Interior Decay of radioactive atoms generates heat to

keep the interior hot Sun

Solar radiation warms Earth’s Atmosphere and surface

Cycles in the Earth System

The Nitrogen Cycle Nitrogen must be “fixed”

The Carbon Cycle Short Term Cycle Long Term Cycle

The Phosphorus Cycle Moves through every sphere but the

atmosphere It is rarely a gas

The Water Cycle Precipitation Evaporation Condensation

Section 3Ecology

Ecology The study of the complex relationships

between living things and their nonliving, or abiotic, environment

Ecosystems

Ecosystem Each ecosystem on Earth is distinct

Self-supporting Producers Consumers Decomposers

Balancing Forces in Ecosystems

The Earth is what type of System? Open, but with limited amount of matter and

energy exchange Organisms use energy and matter

These are limited Populations growth inside a ecosystem is

limited as well Carry Capacity

The largest population that an environment can support at any given time

Ecological Responses to Change

Changes in any one part of an ecosystem may affect the entire system

Environmental change Forest Fire great damage and disruption

Grass and fast-growing plants shrubs and small animal species larger tree species and larger animals

These will return to balance the ecosystem

Energy TransferFood Chains and Food Webs

Sun Ultimate source of energy

Photosynthesis How plants capture solar energy through a

chemical process Food Chain Food Web