Plate Tectonics
______ states that Earth’s continents had once been joined as a single landmass that broke apart and sent the continents adrift
Continental Drift Theory
Why are volcanoes not random throughout the world?
they mostly form at plate boundaries.
Pyroclastic flows can have an internal temperature up to _________ degrees C.
Pyroclastic flows can have internal temperatures of more than 700 C.
An earthquakes characteristics are determined by its ________ and __________
Orientation and magnitude
the displacement of the mantle by earth’s continental and oceanic crust is called _________
Isostasy
The largest supercontinent was called ____
Pangea
random spots in the mantle that are overheated and push the magma up through the crust
What are sills?
Sills form when magma intrudes parallel to the layers of rock
What type of stressor decreases the volume of a material?
compression
Why do mountains have roots?
To counterbalance the enormous mass of the range above earth’s surface
What type of evidence to support Pangea was present from rock formations?
When Pangea began to break apart, large geologic structures (such as mountain ranges) became separated
This should show similar rock types on opposite sides of the Atlantic ocean
What type of volcanoes are formed by violent eruptions?
composite volcanoes
What is the name of the town we studied that was destroyed by a volcanic eruption?
Pompeii
When ___ and ______ reach a critical point, an earthquake can occur.
stress and strain
_________ is all of the processes that form mountain ranges
Orogeny
This is the theory that explains how new oceanic crust is formed at ocean ridges, slowly moved away from the ridges, and destroyed at deep-sea trenches
Seafloor Spreading
Magma composition is determined by what factors?
Temperature, pressure, silica content, and dissolved gases
How are Earthquakes Forcasted?
THEY AREN'T
The _______ is the point at the surface where surface waves from an earthquake spread out
epicenter
What causes large uplifted mountain areas?
It isn't well understood. AKA We don't know!!
What type of plate boundary is described by an oceanic plate being completely subducted, dragging an attached continent behind it toward the subduction zone but does not subduct and instead collides with the other continent
Continental-continental
What is a pyroclastic flow?
Rapidly moving clouds of tephra mixed with hot, suffocating gases are called pyroclastic flows.
What caused the bodies left at Pompeii to vaporize and mummify in place?
pyroclastic flows.
Describe each type of wave.
p-wave :
s-wave :
surface wave :
p-wave : squeeze and push rocks in the direction the wave is traveling
s-wave : the rocks move perpendicular to the direction of the waves
surface wave : which travel only along earth’s surface and cause the ground to move sideways and up and down like ocean waves
Earth's tallest mountain ranges are formed by these boundaries
Earth's tallest mountain ranges, including the Himalayas, are formed at continental-continental plate boundaries