dynamic earth earth systems, plate tectonics, layers, earthquakes, valcanoes
TRANSCRIPT
Earth as a System Four parts:
Geosphere (rock) Mostly located in Earth’s interior
Atmosphere (air) Hydrosphere (water)
Oceans ¾ of the globe Biosphere (living)
Layers of the Earth Crust, Mantle, Core Lithosphere
the crust and the upper mantle Divided into plate tectonics
Asthenosphere Plastic, solid layer of mantle made of rock Allows tectonic plates to move on top of it (slow)
Mesosphere Lower layer of the mantle between the
asthenosphere and outer core
Continued… Outer Core
Dense, liquid layer Outer shell of core made up of liquid iron
and nickel Inner Core
Sphere of solid nickel and iron at center of the Earth
Earth’s inner and outer core make up about 1/3 of earth’s mass
Plate Tectonics Continental Drift
Fossil Evidence of the same kinds of animals living on separate continents.
The types of rocks found on each continent today show similar strata and ages. Mt. Ranges on the coast of West Africa disappear then suddenly reappear again on the coast
Plate Movements Divergent:
Sea Floor spreading: where new land is created. Occurs in the ocean (mid-ocean ridges)
Transform: As 2 plates slide past one another friction
builds. (Earthquakes) Convergent:
Plate collisions Subduction: plates push up continental plates
(Volcanoes) Uplift: Mountains form
Convection Currents Occurs in the magma Magma is heated, becomes less dense
and rises, then cools, more dense and sinks
Heating, cooling (rising, sinking) creates currents = plate movement
Volcanoes Shield:
Large, broad with a crater at the top Slow eruption and lava oozes Examples: Mauna Loa in Hawaii and Mount
Wrangell in Alaska Composite:
Tall, steep, symmetrical (explosive, hard to predict
Examples: Mount Hood in Oregon, Mount St. Helens in Washington (many of these all over the world
… Cinder Cone
Lava in the form of cinders Most common type Examples: Mount Mazama in Oregon (Crater
Lake) Hot Spot: magma emerges from Earth but
not at plate boundaries (middle of plates) Examples: Hawaiian Islands, Galapagos,
Iceland, Yellowstone