Earth's Layers
Is most water on earth usable or unusable to humans?
Unusable
What is deposition?
The process where agents of erosion (wind, water, etc.) lay down sediment.
What theory did Alfred Wegner propose?
Theory of the continental drift
How rocks change from one form to another
Liquid iron and nickel
What is earth primarily composed of?
Rock
Name three causes of weathering.
Heat, Cold, Water, Ice, Gases
Heat
Cold
Water
Ice
Gases
What was the supercontinent that existed approximately 250 million years ago?
Pangea
How do igneous rocks form?
When molten rock (magma and lava) cools and crystalizes
Which layer of earth is most dense?
Inner core
What is the relatively thin layer of gas that surrounds the earth called?
Atmosphere
Define weathering.
The process that breaks down rock and other substances.
How many major plates is the lithosphere broken into?
8
How do sedimentary rocks form?
The inner core, with the combination of the rotation of earth, around the outer core creates a _______ effect.
Dynamo
What are the two types of crust?
Continental and Oceanic
What is the major difference between mechanical weathering and chemical weathering?
Chemical weathering results in new substances and mechanical weathering does not.
What causes tectonic plates to move?
Convection currents in the earth's mantle
How do metamorphic rocks form?
When rock is pressurized and heated deep underground
What are two pieces of evidence used to support the theory of the continental drift?
Evidence of continental drift included fossils that were found on separate continents, landform shapes and features, identical rock formations on separate continents, and climate evidence.
What type of current takes place in the mantle?
Convection
Define erosion.
The process where natural forces move weathered rock and soil from one place to another
What are the three types of plate boundaries, explain each.
Convergent- plates move towards each other
Divergent- plates move away from each other
Transform- plates slide past each other
When sedimentary rocks undergo high heat and pressure, what type of rock do they become?
Metamorphic rock
What do we call the rigid outer layer of earth consisting of the crust and the upper part of the mantle?
Lithosphere