Plates move apart; new crust is built, forming mid-ocean ridges and rift valleys
100
What is a fault?
A fracture, or break, in Earth's lithosphere, along which blocks of rock move past each other
100
An opening in Earth's crust through which molten rock, rock fragments, and hot gasses erupt is called a....
Volcano
100
What day is your test?
THURSDAY
200
Earth's continents were once joined in a single landmass and gradually moved apart. What theory is this?
Continental Drift
200
An earthquake begins at the...?
Focus
200
Describe a shield volcano.
Shaped like a broad, flat dome. It is built up by many eruptions of lava that is relatively low in silica and therefore flows easily and spreads out in thin layers.
200
A Richter Scale measures....
The magnitude of earthquakes
300
What is the difference between a convergent boundary and a transform boundary?
Convergent=plates push together Transform=plates scrap past eachother
300
What's another name for transverse waves?
Secondary waves
300
What causes a fault-block mountain to form?
As the lithosphere is stretched and pulled apart, they form along normal faults.
300
Out of the three types of seismic waves, which is the most destructive?
Surface waves; a combination of P and S waves
400
Name a type of convergent boundary. Describe what happens at that type
Name one of the three types of faults and describe the movement that occurs along that fault
Normal=block to the right moves down. Both are pulling apart.
Reverse=block on left moves down. The two rocks are pushing against each other.
Strike-Slip=move horizontally in opposite directions. Sliding
400
This volcano is usually coned-shaped and is built up of layers of hardened lava and of rock fragments
Composite volcano
400
What causes a folded mountain to form?
As an oceanic plate sinks under the edge of a continent or as continents collide. The crust crumples and bends into folds.
500
Name one piece of evidence that supports continental drift AND plate tectonics
C.D=fossils, climate, geology
P.T=sea-floor spreading, age of the sea floor, ocean trenches
500
What is the epicenter?
The point on the surface directly above the focus
500
Why do most volcanoes occur along plate boundaries where oceanic plates sinks beneath other plates?
As a plate sinks deep into a subduction zone, it heats and begins to melt (magma). If the magma reaches the surface it can build volcanic mountains.
500
How does an earthquake form?
A sudden release of stress (the force exerted when an object presses on, pulls on, or pushes against another object) in the lithosphere