Plate Tectonics
Name one piece of evidence presented by Wegener to support continental drift.
fossil, rock formations, climate
What determines the explosivity of a volcano?
composition of magma
The point on the surface directly above the focus.
Epicenter
all processes involved in mountain building
orogeny
what well known island chain was formed from a hot spot
Hawaii
What are the 3 types of plate boundaries and how do they move?
1. Convergent - collide
2. Divergent - apart
3. Transform - slide past
Which volcano type has quiet nonexplosive eruptions?
shield volcano
What depth of focus would cause the MOST damage?
Shallow
condition of equilibrium that describes the displacement of Earth’s mantle by Earth’s continental and oceanic crust
isostasy
Rapidly moving clouds of tephra mixed with hot, suffocating gases are called
pyroclastic flow
Process where the denser plates descends below the other at convergent boundaries
subduction
Which magma has the highest silica content?
rhyolitic
Section along an active fault that has not experienced an earthquake in a long time
Seismic Gap
true/false. If mass is removed from a mountain, then the roots descend in response.
false. roots will rise
How are magnetic reversals tracked?
earth's crust
Name the 3 types of convergent boundaries
oceanic-oceanic
oceanic-continental
continental-continental
1. material that forms volcano
2. type of eruptions
2 factors that help predict the probability of earthquakes.
1. history of earthquakes in area
2. rate at which stress builds up
What boundary do long chains of underwater volcanic mountains called mid ocean ridges form?
divergent
Name the 2 boundary types most volcanoes and earthquakes form around
convergent and divergent
Describe the process of how Convection Currents move plates
As the material heats it rises, the heated material spreads out pushing the plates apart at divergent boundaries. The cooled material falls, pulling the plates down and together at convergent boundaries.
Explain how a caldera forms.
after an eruption that empties the magma chamber and the volcano collapses forming a bowl shaped depression
Explain how a strike slip fault generates an earthquake.
shear stress causes horizontal movement along a fault plane
What is the purpose of mountain roots?
counterbalance the mass of the mountain range
Explain how fault-block mountains are formed.
Form between large faults when pieces of crust are dropped downward due to tensional forces