Chapter+Two+Key+Concepts

1. **Weathering** 2. **Erosion** __** Internal Forces of Change **__ 1.**Coliding/Spreading of Plates** 2. **Squeezing/Sliding of Plates** 3. **Results**
 * __ External forces of Change __**
 * breaks down rock
 * phisical: broken intp amaller pieces (ice)
 * Chemical: changes the chemical makeup of rock (CO2 in rainwater)
 * Wind
 * Glacier (Sheet or Mountain)
 * Flowing H2O
 * Create mtns.
 * Continent Growth
 * Island Formation
 * Rifts
 * Fold -> bend in rock layers
 * Fault -> cracks in Earth's crust
 * Earthquake
 * Volcanic Eruption
 * Hot Springs/Geysers

= **__ The Water Cycle __** = > 2. **Condensation** > 3. **Precipitation** > 4. **Runoff**
 * 1. **Evaporation**
 * liquid to vapor (gas) by heat of the sun
 * warm, moist, air cools (clouds)
 * the falling to earth of any form of water
 * process of forming a chemical precipitate
 * gravity pulls H2O to oceans



__** Inside the Earth **__


 * Crust **
 * 0-45 milies below Earth's surface
 * less than 1800 Degrees Fahrenheit
 * Mantle **
 * 1860 miles below Earth's surface
 * 1800-6300 Degrees Fahrenheit
 * Outer Core **
 * 3200 miles below Earth's surface
 * 6300-7200 Degrees Fahrenheit
 * Inner Core **
 * 3960 miles below Earth's surface
 * 7200-8500 Degrees Fahrenheit

__** Asteroids, Comets, and Meteoroids **__ __﻿__ __** Forces of Change **__
 * Asteroids **
 * Small, irregular shaped, planet-like objects
 * Found mainly between Mars and Jupitar in the Asteroid Belt
 * A few follow paths that cross Earth's orbit
 * Comets **
 * Made of icy dust particles and frozen gases, look like bright balls with long, feathery tails
 * Orbits are inclined at every possible angle to Earth's orbit
 * May approach from any direction
 * Meteoroids **
 * Pieces of space debris-chunks of rock and iron
 * When they enter Earth's atmosphere, friction usually burns them up before they reach the Earth's surface, the ones that collide with earth are called meteroids.
 * Can significally afffect the landscape
 * Subduction **
 * The heavier sea plate dives beneath the lighter continental plate. Plunging into the Earth's interior, the sea plate becomes molten material. Then, as magma, it bursts throught the crust to form volcanic mountains.
 * Examples: The Andes, a mountain system is South America.
 * Accretion **
 * Pieces of the Earth's crust come together slowly as the sea plate slides under the continental plate. This movement levels off seamounts, underwater mountains with steep sides and sharp peaks, and piles up the resulting debris in trenches. This build up can cause continents to grow outward.
 * Examples: most scientists believe that much of western North America expanded outward into the Pacific Ocean over more than 200 million years.
 * Spreading **
 * One plate moves under the other, often forming an island chain at the boundary. The resulting rift, or deep crack, allows magma from within the Earth to well up between the plates. The magma hardens to build undersea volcanic mountains or ridges and some islands.
 * Examples: Occurs down the middle of the Atlantic Ocean's floor, pushing Europe and North America away from each other.
 * Faulting **
 * Occurs when the folded land cannot be bent any further. Then the Earth's crust cracks and breaks into huge blocks. The blocks move along the faults in different directions, grinding against each other. The resulting tension may release a series of small jumps, felt as minor tremors on the Earth's surface.
 * Examples: San Andreas Fault

=__ Plate Tectonics __= The Earth is made up of shifting plates that are constantly moving. There are 3 types: =__ Landforms __= __﻿__ =__** Earth's water **__=
 * Colliding plates that crash into each other and cause subduction.
 * Some plates drift away from each other. This is called spreading.
 * Some plates slide together. This act is called faulting.
 * Landforms are the natural features of the Earth's surface.
 * Landforms often contain rivers, lakes and stereams.
 * The Earth's most visible landmasses are the 7 continents.
 * A continental shelf is an underwater extension of one of these landmasses called a coastal plain.


 * 70 % of the planets surface is made up of water. This is called the Hydrosphere.
 * Oceans, lakes, rivers, and any other water source is also included in the hydrosphere.
 * 97% of the Earth's water source is salt water like in the oceans.
 * 3% of our water sources are usable by humans.


 * Weathering **
 * The Earth is made by two kids of weathering
 * Physical weathering occurs when lage massa of rock are physicallybroken down to smaller pieces.
 * Chemical weathering changes the chemical makeup of rocks


 * Earth's Heights and Depths **
 * **Mount Everest** the highest point on Earth which is ** 29,028 above sea level **
 * The lowest dry land point at ** 1,349 ** below sea level is the Shore of the ** Dead Sea ** in ** SouthWest Asia **
 * Earth's deepest depression is SouthWest of Guam in the ** Mariana Trench, ** which is a narrow underwater canyon about ** 35,827 ** feet deep


 * Folds and Faults **
 * ** Folds: ** Bends **, ** in the layers of rock
 * **Faults:** Plates that grind or slide past each other, creating cracks in the Eath's crust