Earth as a System(Sect 1-2 & 1-4)

Satellite image of ash cloud being spewed from fissure in Chile’s Puyehue-Cordón Caulle Volcanic Range, June 7, 2011

• A system is an organized group of related objects or components that work independently and interact to create a whole.

• Systems have matter and energy that flow freely through the system.

• Matter is not part of this exchange.

• How matter and energy are transferred determines whether the system is closed or open.

• A closed system is a system where only energy is transferred or exchanged with its surroundings.

A. System

A. System

• As a closed system, the jar of tea does not share matter with its surroundings.

• Energy, in the form of light, can enter.

• Energy can leave, too, as heat passes out through the glass walls of the jar. But if the jar is tipped over, the tea stays in.

Example of a Closed System

An open system includes the transfer and exchange of both matter and energy with the system's surroundings.

A. System

An example of a open system: The jar of iced tea would become an open system if the lid of the jar were to be removed, allowing some of the tea to evaporate. If a lemon slice were added, new matter would enter the system.

B. Earth’s Major Spheres

Atmosphere

Hydrosphere

Geosphere

BiosphereAll Air, gases

All Liquid/Frozen WaterAll Rock material

All Living Things

C. Atmosphere

• Thin gaseous envelope that surrounds the Earth

• Approximately 100 km above the Earth’s surface.

The Atmosphere Provides:• Air we breath• Protection (solar heat and radiation)

• Energy exchanged between space, atmosphere and Earth’s surface produce weather and climate.

C. Atmosphere

• Geosphere is divided into 3 main parts based on composition of material (Crust,Mantle Core):

D. The Geosphere

• Crust: – Continental (thicker less dense)– Oceanic (thinner, more dense)

D. The Geosphere

• Mantle: – Lithosphere = crust + uppermost rigid mantle– Asthenosphere = upper mantle that is softer, flows– Lower mantle = also called mesosphere

C. The Geosphere

• Core: made of iron and nickel– Outer core (liquid), causes magnetic field– Inner Core (solid): even though hotter, pressure

too high for liquid state)

D. The Geosphere

• The surface of Earth is covered with plates:D. The Geosphere

• Plate Tectonics: Theory (i.e., an explanation) as to why continents have moved and the occurrence of EQs and volcanic eruptions.

• Constructive and destructive process

E. Biosphere

E. Biosphere

• Includes all life on Earth

• Extends from the ocean floor upward into the atmosphere.

• Living things form ecological communities called biomes.

• Examples of biomes include:• Deserts• Grasslands• Tropical Rainforests

F. Hydrosphere

F. Hydrosphere• All of the Earth’s water makes up the hydrosphere.

• Water is continually moving• Evaporation• Precipitation• Running Water (i.e. streams and rivers)

• Oceans account for 97% .

• Fresh water accounts for 3%• Groundwater, streams, lakes and glaciers• Sustaining life• Creates Earths Features

• Availability of fresh water determines where many organisms can live.

F. Hydrosphere

Atmosphere

Hydrosphere

Geosphere

Biosphere

•Spheres are interconnected and interdependent•Soil is an interface between all of these

• The Sun (light) drives external processes that occur in atmosphere, hydrosphere and biosphere

G. Earth as a System

• Humans can alter the system as well.• Environmental Science: focuses on relationships

between people and natural world.• Resources that society depends on are formed by

natural processes on Earth– Water, soil, metal and nonmetal minerals (ores), and

energy

H. People and The Environment

Sample from a zinc ore mine in Franklain, NJ

H. People and The EnvironmentRenewable Resources•Replenished over short time•Ex: plants/animals for food, natural fibers, forest products for lumber and paper•Energy: flowing water, wind, solar energy

Nonrenewable Resources•Replenished only over VERY long time periods because process to create is SLOW•Ex: Aluminum, Copper (though these can recycle)•Energy: fossil fuels like oil, natural gas, coal

H. People and The EnvironmentPopulation•How long will supplies of basic resources last???

http://www.census.gov/main/www/popclock.html

• As population increases, so does demand for resources. Especially as world societies become developed.