Earth Science Flashcards
Theory of Plate Tectonics:
The lithosphere is broken into large plates that interact and cause geological events
Tectonic Plates
Large plates that float slowly on a layer of fluid-like rock in the Earth’s Mantle
Layers of the Earth and their Order
Crust, Upper Mantle, Lower Mantle, Outer Core, Inner Core
Primary Wave 4 Aspects
Cause rock particles to move forward and backward
(compress and expand like an accordion),
Move the fastest,
Are the first ones detected
in an earthquake,
Can travel through liquids and solids (Earth’s
interior)
Secondary Wave 3 Aspects
Move slower than P waves, faster than surface waves, Causes rock particles to move up and down or side to side, Can only travel through solids
Surface Wave 4 Aspects:
On the surface and often cause, the greatest damage Cause rock particles to move up and down, and side to side, Slowest of the three waves, Can travel along the surface of Earth (not through Earth’s interior)
Mid Ocean Ridges
Mountain Ridges on the ocean floor
Sea Floor Spreading
The process of magma rising to the surface at mid ocean ridges to from new crust.
Divergent Plate Boundaries
When two tectonic plates move away from each other
Convergent Plate Boundaries
When two tectonic plates move towards each other
Transform Boundaries
When two tectonic plates slide past each other
Mantle Convection
the process of the mantle heating up and rising to the surface where it cools and sinks down once more, repeating the process
Hot Spots
hot regions of Earth’s
mantle where magma rises to the
surface by breaking through weak parts
of the lithosphere
Hot Spot Volcanoes
Tectonic plates can move over fixed
areas called hot spots, creating a trail
of volcanic islands, Volcanoes can form above hot spots as the
magma rises and melts through the crust
Fault
Fractures (cracks) in the Earth’s
crust. They can be as small as a
few millimeters and as large as
several kilometers.
Normal Fault
Tension causes crust to drop down
Reverse Fault
Compression causes crust to move up
Strike Slip Fault
Shearing forces cause the crust move alongside each other
Earthquake
Sudden shaking of the Earths crust caused by a sudden release of energy caused by movement along faults
Trenches
Deep Valleys on the ocean floor
Focus
The point where
breakage of rock inside
Earth first happens
Epicentre
the point on Earth’s surface above where an earthquake starts (above the focus)
Seismic Wave
an elastic wave in the earth produced by an earthquake or other means
Magnitude
the size of an Earthquake
Volcano
opening in Earth’s
surface where magma and
other materials are released
Lava
Magma that has been released to the Earths surface
Three types of Mountain formation
folding, fault block, volcanic activity
Folded Mountain Formation
Rock is compressed at convergent plate boundaries
Fault Block Mountain Formation
Formed along faults where large pieces of rock are forced up while others are forced down
Volcanic mountain formation
Volcanic mountains form when
molten material reaches the
surface through a weak area of
the crust.
