The Geosphere

The Earth as a System

The Earth is a system of 4 interacting components. Consists of:

- Geosphere - Hydrosphere- Atmosphere - Biosphere

The GeosphereComposition

• The solid part of the Earth (rocks, minerals, soil, etc.)– Most of the geosphere is below the surface

What is it?

Lithosphere Cool, rigid layer that includes the crust; divided into plates

Asthenosphere Flexible layer of the mantle that flows slowly, allowing plates above it to move

Outer Core Liquid nickel and iron

Inner Core Solid nickel and iron

• Look at the world map. Does anything look like it could fit together like a puzzle?

The GeospherePlate Tectonics

Pangaea – Wegener’s idea that all of Earth’s continents were joined into one giant landmass 200 million years ago.

The GeospherePlate Tectonics

• The tectonic plates ride atop the asthenosphere, moving in different directions

Boundary Movement Result

Convergent 2 plates move together

Mountains, volcanoes, earthquakes

Divergent

Transform

Convergent Plate Boundaries

Continental-continental

Oceanic-continentalOceanic- oceanic

The GeospherePlate Tectonics

• The tectonic plates ride atop the asthenosphere, moving in different directions

Boundary Movement Result

Convergent 2 plates move together

Mountains, volcanoes, earthquakes

Divergent 2 plates move apart

Ocean ridges (volcanic), rift valleys, earthquakes

Transform

Divergent Plate Boundaries

Mid-ocean ridge

Rift Valley

The GeospherePlate Tectonics

• The tectonic plates ride atop the asthenosphere, moving in different directions

Boundary Movement Result

Convergent 2 plates move together

Mountains, volcanoes, earthquakes

Divergent 2 plates move apart

Ocean ridges (volcanic), rift valleys, earthquakes

Transform 2 plates slide past each other

Faults, earthquakes

Transform Plate Boundaries

The GeospherePlate Tectonics

Global Earthquake Distribution Global Volcano Distribution

The GeosphereEarthquakes Volcanic Eruptions

How does it happen?

Earth’s crust slips along a fault (crack in the crust)

Local Effects

Destruction, injuries, death

Global Effects

Tsunamis

Which of these geologic hazards poses the greatest threat to the environment? Why?

The GeosphereEarthquakes Volcanic Eruptions

How does it happen?

Earth’s crust slips along a fault (crack in

the crust)

Pressure of magma inside the volcano becomes so great that it blows open the solid surface.

Local Effects

Destruction, injuries, death

Destruction, injuries, death, mudflows,

*improved soil fertility

Global Effects

Tsunamis Ash clouds from major eruptions can

block sunlight & change drop the

average global temp.

The GeosphereErosion

• Rocks on the surface are changed by wind, running water, and weather.

• Erosion is the removal and transport of weathered surface materials.

• Over long periods of time, erosion can wear away entire mountains and produce spectacular landforms.

How is the land in this picture being used?

The Land

How We Use LandUrban land = land covered mostly with buildings & roads and containing 2500 or more people.

Rural land = land containing few people & large areas of open space.

Think-Pair-ShareHow are each type of land cover important to

people?

The Urban-Rural ConnectionThink About It… Are people dependent on the

resources produced in rural areas?Ecosystem services – resources produced by natural

& artificial ecosystems

Development of Marginal Lands• Some suburbs have been built on land that

is not well suited to support buildings.• This land is prone to landslides because it is

unstable– Ex: Los Angeles, Mexico City

Urban Environmental ConditionHeat Islands – increased temperature in a city

Why? - roads & buildings absorb more heat than vegetationEffects? – local weather patterns change, more rainfall in cities

Pollution of air, water, & land

Urban Planning• Land-use planning is essential for pleasant

urban living experiences. • Ex:

– Transportation in cities involves mass transit systems (buses, trains)

• Mass transit saves energy, reduces traffic, lowers air pollution, & limits the loss of land to roads & parking lots

– Open space is set aside in urban areas for recreational enjoyment (parks, gardens, bike paths, hiking trails)

• Open spaces absorb CO2, produce oxygen, filter pollutants, lower temperatures, absorb rainwater

Land Management & ConservationLand Type What is it? How is it used by

people?What are the

problems/threats to this land?

How can it be maintained / protected?

Farm landLAND USED FOR

CROPS AND FRUITS

FOOD URBAN DEVELOPMENT

FARMLAND PROTECTION

PROGRAM

Range landLAND THAT SUPPORTS

VEGETATION (GRASSES)

GRAZING LIVESTOCK

OVERGRAZING PUBLIC RANGELANDS

IMPROVEMENT ACT

Forest landLAND THAT SUPPORTS

TREES

WOOD, LUMBER,

PAPER, ETC.

DEFORESTATION (CLEARING WITHOUT

REPLACING)

REFORESTATION

Parks & Preserves

LAND PROTECTED

AGAINST DEVELOPMENT

RECREATION, WILDLIFE REFUGE,

PROTECTING ENDANGERED

SPECIES

INCREASED DEVELOPMENT,

VISITOR DESTRUCTION &

LITTERING

US WILDERNESS

ACT –PROTECTS

FROM EXPLOITATION

Designing A Community• You are a land-use planner. Design a model

community that is to be home for 1000 people. Name your community & tell us where in the world you are located.– Sketch your plans for the following:

• Housing• Commercial• Transportation routes• Open spaces• Community services (electricity, water, trash

collection, police & fire protection, schools, hospitals, etc.)

• Where will resources come from?