Layers of the Earth
Inner Core, Outer Core, Mantle, Crust
Inner Core
Solid, mostly iron extremely dense center of the Earth
Outer Core
Liquid, mostly iron, second layer from the inside of the Earth
Mantle
Liquid, where convection occurs, below the crust
Crust
Extremely thin, cool, brittle layer broken into lithospheric plates
Two Types of Crust
Oceanic & Continental Crust
Oceanic Crust
Thin, very dense, newer crust; under the ocean
Continental Crust
Older crust that is not as dense; land that we live on
Convergent Boundary
Formed when two plates are pushing together
Divergent Boundary
Formed when two plates are moving away from each other
Transform Boundary
Formed when two plates are sliding past each other, like the San Andreas Fault
Continental-Continental Convergent Boundary
Two pieces of continental crust push together; forms folded mountains such as the Appalachians or the Himalayas
Oceanic-Oceanic Convergent Boundary
Two pieces of oceanic crust push together; forms trenches & island arcs such as the Tongan Trench & islands
Continental-Oceanic Convergent Boundary
A piece of oceanic crust pushes underneath a piece of continental crust; forms volcanic arcs such as the Andes and the Northwest US (Cascades Volcanic Arc)
Oceanic-Oceanic Divergent Boundary
Two pieces of oceanic crust are pushed away from each other as magma creates new crust in the middle; forms mid-ocean ridges such as the Mid Atlantic Ridge
Continental-Continental Divergent Boundary
Two pieces of continental crust are pushed away from each other; forms a rift valley and eventually new oceans such as the East African Rift Valley and the Red Sea
Hot Spot Volcano
A volcano that forms in the middle of a plate instead of at a plate boundary, as the crust moves over a super-hot stationary column of magma; examples: Yellowstone, Hawaii
Hawaii
Islands formed by a hot spot volcano
Yellowstone
Hot spot volcano located in the continental US
Iceland plate boundary
Island that sits on top of the Mid Atlantic Ridge and is being pulled apart
Mount St. Helens
Volcano in the northwestern US that formed due to oceanic-continental convergence
Pacific Ring of Fire
Ring around the Pacific Ocean where many volcanoes and earthquakes occur
Tongan Trench
Trench that formed due to oceanic-oceanic convergence; formed the Tongan Islands
Appalachian Mountains
Formed due to continental-continental convergence; formed when Africa collided with America during the formation of Pangaea
Pangaea
Supercontinent that existed 200 million years ago
Sea-floor Spreading
The creation of new oceanic crust at divergent plate boundaries
Paleomagnetism
The study of iron-bearing minerals along new oceanic crust; iron particles match up identically along either side of the mid ocean ridge
San Andres Fault
Transform fault in California
Subduction Zone
Area where one plate is being pushed below another plate, into the mantle
Features of Convergent Boundaries
Folded mountains, subduction zones
Features of Divergent Boundaries
Mid-ocean ridges, rift valleys, flood lavas
Earthquakes
Shaking of the crust that occurs due to movement at plate boundaries
Fault
Break or crack in the Earth's crust where movement has occurred
Alfred Wegener
Scientist that proposed the theory of Continental Drift
Continental Drift
Alfred Wegener's theory of plate movements -- "the plates are moving, but we don't know why
Harry Hess
Scientist that proposed the theory of Sea-floor Spreading
Coastal Plain
Province of VA that is made of young, unconsolidated sediment produced by erosion of the Appalachian Mountains
Piedmont
Province of VA known for rolling hills underlain by ancient igneous and metamorphic rocks
Blue Ridge
Province of VA that is a high ridge that separates the Piedmont from the Valley and Ridge; made of billion-year-old igneous and metamorphic rocks
Valley and Ridge
Province of VA known for long parallel ridges and folded/faulted sedimentary rocks produced during the collision of North America & Africa (formed the Appalachian Mountains --- NOT the Appalachian Plateau!)
Appalachian Plateau
Province of VA know for rugged topography and lots of coal
Ring of Fire
Area of frequent earthquakes and volcanoes that surrounds the Pacific Ocean