• 1. conduction– transfer of energy (mostly in

solids) by collisions of particles• 2. convection– transfer of energy by currents

moving through liquids or gases (caused by density differences)

• 3. radiation– transfer of energy through empty

space (no molecules needed)–Ex. energy from the Sun

3 Forms of Energy Transfer

Recycling of Materials Amongst Earth’s Spheres

• Earth is constantly recycling materials– maintains an

overall balance through biogeochemical cycles• water• carbon• etc.

Solar Energy Drives the Water Cyclecondensation

The Water Cycle

1. precipitation–water that

falls from clouds to Earth• drizzle, rain,

snow, sleet, hail

2. infiltration– water soaks into soil

from the surface

3. ground water–water under the

ground; soil is saturated

4. evaporation– warmth from Sun

causes liquid water to turn into water vapor

5. transpiration–when plants give off

water vapor through stomata in their leaves

evaporation

6. condensation– water vapor cools until it turns back into liquid

– forming clouds, fog, or dew

condensation

Groundwater Pollution• pollutants in soil carried by

infiltration into groundwater– oil– nitrates & phosphates• from fertilizers

– pesticides– farm wastes– sewage– salt• to melt ice

– chemicals & hazardous wastes– and more…

• can be a reason for site to be designated a “brownfield”

• remediation (clean up ) expensive– prevention

best

Carbon Cycle

Changes in CO2 & Climate• CO2 levels have

risen steadily since mid-1800s– primarily due to

human activities• combustion of

fossil fuels– coal– gasoline– natural gas

• deforestation– decreased

photosynthesis

• avg. global temps have ~1°C since late 1800s

• Possible effects:– sea-level rise– more/stronger

storms/hurricanes– more frequent heat

waves/droughts– relocation of major

crop-growing areas

Changes in CO2 & Climate

Common Air Pollutants• air pollutant– any airborne gas or

particle concentrated enough to harm people or the environment

– natural causes• volcanoes• forest fires

– human causes• combustion of fossil

fuels (automobiles, factories, etc.)

Acid Rain• pollutants (SOX & NOX)

react w/ H2O vapor in air

• acidity measured using pH

• effects– harm to plants/animals– damage to structures

made of limestone/marble• remember… carbonates

bubble in acid

Weathering• breakdown

of rocks at Earth’s surface

• 2 types:• chemical

• mechanical (physical)

Chemical Weathering• rock is broken down by chemical action

• changed into new substances• agents include acids & oxygen

•rainwater naturally acidic

–CO2 dissolved in rainwater carbonic acid• can weather

carbonate-based rocks• ex. marble &

limestone (CaCO3)

Chemical Weathering

•other rocks are very resistant to acid and do not weather easily

–quartz-based rocks•ex. quartzite

& sandstone (SiO2)

Mechanical (Physical) Weathering• rock is split, cracked, or broken into smaller

pieces of the same material–NOT changed into new substances

The Rock Cycle• continuous process causing rocks to change

from one form to another

Rock Cycle Movie

1. sedimentary– formed by compaction

& cementing of layers of sediments

2. metamorphic– formed by effects of

heat & pressure on other rocks

3. igneous– formed by solidification

of hot, molten rock

BrainPop 3 Types of Rocks

3 Major Classes of Rocks

Sedimentary Rocks• made of

sediments

• cover most of Earth’s surface

Metamorphic Rocks• metamorphism–process by which a rock’s structure is changed

by pressure & heat

•granite gneiss

•shale slate phyllite schist

Examples of Metamorphic Rocks & What They Formed From

• limestone marble

• sandstone quartzite

• form due to MELTING & solidification– Intrusive• magma cools slowly

deep inside Earth– crystals medium to

coarse texture

– Extrusive• lava cools quickly

on/above surface of Earth– crystals very small

or not seen at all

Igneous Rocks

Convection Currents in Magma

• drives plate tectonics

Convection in the Mantle Animation

What Is Plate Tectonics?

• theory that describes formation, movements, & interactions of Earth’s lithospheric plates

Types of Plate Boundaries

• Earth’s lithosphere is broken in to large plates–movement @ plate boundaries determines type

1. divergent2. convergent3. transform

Divergent Boundaries• plates move apart• most are along ocean floor– spreading @ mid-ocean ridges molten rock

forces through cracks (rifts) in valley

Mid-Ocean Ridge• Mid-Atlantic Ridge

Convergent Boundaries• plates move closer together

Transform Plate Boundary• plates slide past each other at fault– stress released earthquake– Ex. California—San Andreas Fault

N

Transform Boundary--San Andreas Fault Animation

Locations of Earthquakes & Volcanoes• occur in concentrated areas @ plate boundaries– strain builds up earthquakes–molten rock rises volcanic activity• Pacific Ocean Ring of Fire

Plates & Volcanoes Video

Ringof

Fire