Earths Physical Geography Forces Shaping the Earth Inside

Earth’s Physical Geography Forces Shaping the Earth

Inside the Earth • Earth is made up of several layers, each of which has different characteristics – Inner Core – Outer Core – Mantle – Crust – Atmosphere

Inside the Earth • Inner Core – Very hot, dense, solid ball – Roughly 1500 miles in diameter – Roughly 3300 miles below the surface – Mostly made up of iron and nickel – Under immense pressure

Inside the Earth • Outer Core – Metal is in liquid state – Temperature can reach as hot as 8, 500 o. F – Still primarily iron and nickel, but with silicon and oxygen added – Roughly 1630 miles below the surface

Inside the Earth • Mantle – Layer of hot, dense rock • Mostly silicates • Roughly 1770 miles thick • Solid nearest the core • Squishy nearest the crust – Magma: Melted rock below the Earth’s surface – Movement in the mantle relieves pressure

Inside the Earth • Crust – Thin, rocky shell that contains land forms – Maximum 62 miles deep – Supports the continental plates – Volcanos that release pressure from the mantle (lava)

Shaping the Earth’s Surface Plate Tectonics • Plate Movements – Each continent sits on a separate plate – Plates move 1 to 7 inches per year – 200 million years ago, Earth had a single super continent: Pangaea Earth’s crust is in a constant state of motion

Shaping the Earth’s Surface

Shaping the Earth’s Surface Plate Tectonics • When Plates Meet – Pulling Away causes a rift in the crust that will fill in with material from the mantle as the gap widens • Usually in ocean areas such as the central Atlantic • Iceland East Africa Earth’s crust is in a constant state of motion

Shaping the Earth’s Surface Plate Tectonics • When Plates Meet – Colliding: Ocean plate collides with land mass • Ocean plate is thinner • Land mass is thicker • Ocean plate pushes below land plate, creating pressure and forcing magma to the surface Earth’s crust is in a constant state of motion

Bell Ringer 02 -01 1. When an oceanic plate collides with a continental plate, does the ocean crust ride on top, go underneath, or crumple against? 2. A rift on the ocean floor causes what actions? 3. How fast is the North American continental plate moving, and in what direction?

Shaping the Earth’s Surface Plate Tectonics • When Plates Meet – Volcanoes: Earth relieves pressure in the mantle (caused by one edge of crust slipping under another) by expelling magma through vents – “Earth zits” Earth’s crust is in a constant state of motion

Shaping the Earth’s Surface Plate Tectonics • When Plates Meet – Colliding: Two land masses meet • Causes upward thrust of land mass into mountains • Mostly sedimentary rock, but may be small amounts of magma Earth’s crust is in a constant state of motion

Shaping the Earth’s Surface Plate Tectonics • Earthquakes – May be caused by plate collision • Convergent: Two plates running into each other • Divergent: Two plates ripping apart from each other Earth’s crust is in a constant state of motion

Bell Ringer 02 -02 1. What three things happen (one after the other) to cause a volcano? 2. What grows over millions of years when two continental crusts collide? 3. The terms Convergent and Divergent refer to what motions?

Shaping the Earth’s Surface Plate Tectonics • Earthquakes – May be caused by movement along faults • Fault: A crack in the Earth’s crust • Transform: Two pieces of crust slipping against each other along a fault Earth’s crust is in a constant state of motion

Bell Ringer 02 -03 1. What is defined as a crack in the Earth’s crust that contributes to earthquakes? 2. What is an earthquake? 3. Name three things that cause weathering

Shaping the Earth’s Surface • Weathering – The systematic breakage of rock caused by water, ice, chemicals, or plants • Erosion – Movement of weathered rock caused by water, wind, and ice

Shaping the Earth’s Surface

Earth’s Physical Geography Landforms and Water Resources

Types of Landforms

Types of Landforms • On Land – Mountains: • huge towers of rock • The tallest landforms ranging from as small as 2, 000 feet to well over 25, 000 feet above mean sea level • Mount Everest is the tallest mountain above sea level at 29, 028 feet

Types of Landforms • On Land – Hills: • Lower and more rounded that mountains • Less than 2000 feet between the lowest and highest points • May be worn down mountains or carved up plateaus

Types of Landforms • On Land – Valleys: • Long stretch of land that is lower than the land on either side • Generally occur between hills and/or mountains • May be caused by shifts in the underlying crust or by running water

Types of Landforms • On Land – Flatlands: Two types based mostly on height above mean sea level • Plains: Flat lowlands typically found along coasts and lowland river valleys • Plateaus: Flat highlands typically found at higher elevations in inland locations

Types of Landforms • Special Landforms – Defined based on their relationship to water – Isthmus: • A narrow strip of land connecting two larger land masses • Water (generally an ocean or sea) on two sides

Types of Landforms • Special Landforms – Defined based on their relationship to water – Peninsula: • A narrow strip of land connected to a larger land mass on one side • Water (generally an ocean, sea or lake) on three sides

Types of Landforms • Special Landforms – Defined based on their relationship to water – Isle: • Smaller than a continent • Completely surrounded by water on all sides

Types of Landforms • Under the Oceans – Continental Shelf • A plateau that lies off the coast of each continent • Stretches for several miles under water • Drops off suddenly toward the ocean floor

Types of Landforms • Under the Oceans – Trenches • Deep cuts in the ocean floor • The deepest trench in the world is the Marianna Trench located in the western Pacific Ocean – Plunges to 36, 198 feet below sea level

The Water Planet • Roughly 70% of the Earth’s surface is water • Water Forms – Liquid • Streams / Rivers • Lakes • Oceans / Seas – Solid • Glaciers • Ice Bergs – Atmospheric water vapor

The Water Planet • Salt Water – All oceans on Earth are part of one continuous body of salt water – Oceans and seas make up 97% of the Earth’s surface water • Bays and Gulfs are smaller • Straits and Channels are narrow connectors

The Water Planet • Fresh Water – Only 3% of Earth’s water is fresh • Mostly frozen in polar ice – Lakes • Large inland bodies of fresh water • Often not safe to drink unless it has been filtered or purified

The Water Planet • Fresh Water – Rivers / Streams • Long, flowing bodies of water • Source: where the river originates • Mouth: where the river empties into a lake, bay, sea, or ocean • Tributaries: smaller streams that flow into rivers

The Water Planet • Delta: – Marshy land mass forming between the end of a river and the start of the sea – Buildup of sediment carried by a river that settles when the water slows down – Brackish

The Water Planet • Fresh Water – Groundwater: Water filtered through soil – Aquifers: Layers of rock through which groundwater flows • Aquifers may be tapped into for wells • Aquifers may produce springs or oases

The Water Planet • The Water Cycle – The process by which water moves from the oceans to the air, to the ground, and back to the oceans – Uses Evaporation, Condensation, Precipitation, and Collection to make the cycle work

The Water Planet • The Water Cycle 1. Evaporation: The process of changing from liquid to gas (water vapor) caused by warming collected bodies of water 2. Condensation: The process by which gas becomes liquid (dew point) caused by cooling 3. Precipitation: The process by which liquid falls from the air to the ground (rain, snow, sleet, etc. ) 4. Collection: Water comes together to form lakes, rivers, and oceans, repeating the cycle