Forces that Change Earth’s Surface I-Interacting Earth Systems: A-Three spheres of the earth: 1- Lithosphere = rock or land 2- Hydrosphere = water 3- Atmosphere = gases

B- External Forces: wear the land down to sea level. 4- The exchange of energy between the three spheres cause changes in the Earth’s surface. B- External Forces: wear the land down to sea level. 1- Weathering breaking down of rocks into smaller pieces. a- ice, rain, and gases.

2- Types of Weathering: a- Physical weathering: ~Frost Action: repeated freezing and melting {Glaciers}

Water seeps into cracks and expands when it freezes breaking rock apart

~Root-pry: roots grow between cracks and grow causing rocks to break apart.

~Gravity: pulls loosen rocks & soil down. {Landslide} ~Abrasion: wind & water carry solid particles that sand down rock.

b- Chemical weathering: changes occur in the mineral composition or chemical makeup of rock. ~Water: dissolves soluble rock ~Oxidation: Oxygen combines with another substance to form a new material.

~Carbonation: A weak acid is formed when carbon dioxide dissolves in water called carbonic acid which dissolves rock.

~Sulfuric acid: Acid Rain When sulfurous gases combines with water ~Sulfuric acid: Acid Rain When sulfurous gases combines with water. Wears away rock and other materials very quickly.

C- Internal Forces: Forces C- Internal Forces: Forces that produce mountains, earthquakes, & volcanoes. 1-Mountains, Plains, & Plateaus

a- Mountains produced mainly by folding and faulting. ~Folding takes place when the crust presses rock causing it to bend.

~Faulting occurs when forces in the crust squeezes or pull causing it to crack or break along a fault = stress in crust.

~Mountains can also be formed by ~Mountains can also be formed by volcanoes: Lava pours out cools pours out cools forming layers of igneous rock.

b- Plains: are broad, flat regions found at low elevation b- Plains: are broad, flat regions found at low elevation. Made of sedimentary rock layers underwater that have slowly raised.

c- Plateaus: Large area of flat-topped rocks, caused by faulting or lava flows.

D- Earthquakes: Sudden movements of rocks sliding along faults in the crust. Earthquakes cause strong vibrations that travel through the Earth. Earthquakes are measured by seismic graphs which measure earthquake waves

1- Three Types of Waves: a- Primary waves (P-waves) can travel through liquids and solids. b- Secondary waves (S-waves) travel only through solids. c- Longitudinal waves (L-waves) surface waves.

E- Structure of Earth: 1- Crust: Outer layer of Earth. Composed of solid rock material about 8-32 km thick. a- Moho: between the crust and Mantle

2- Mantle: Below the crust about. 2900 km thick consisting of iron 2- Mantle: Below the crust about 2900 km thick consisting of iron and magnesium. 3- Outer Core: Below the mantle about 2300 km thick liquid. {S-waves cannot go through it} 4- Inner Core: Solid material about 1200 km {P-waves travel faster through it}

F- Continental Drift: was proposed by Alfred Wegener in 1912, based on the continents fitting together like a puzzle known as Pangea {pan-jee-uh}

1-Wegener also based his theory of fossils, rocks, mountains, and glacial features found on both sides of the Atlantic.

G- Seafloor Spreading Oceanographers discovered an underwater mountain ridge running north-south down the middle of the Atlantic Ocean (Mid-Atlantic Ridge). Along the ridge, there was volcanic activity. This building of new rock which moves east and west supports Wegener theory.

H- The Theory of Plate Tectonics is the combination of continental drift and ocean floor spreading. 1- According to the theory the Earth’s crust is broken up into large plates that move an interact. 2- Scientist believe the plates move due to the heat is the mantle circulating.

Mapping the world

A-Latitude- The Earth is a sphere if you cut it horizontally or vertically into circles. The distance between the North Pole and the equator is 900. If a circle is drawn around the Earth at each degree this is equal to a line of latitude.

3. Equator = 00 latitude. 4. Lines of latitude run west to east and are measured in degrees north-south.

B-Longitude: Lines run north-south and are measured in degrees west-east. 1-00 longitude = the Prime Meridian. Greenwich England.