Continental Drift
According to Wegener's continental drift hypothesis, there once was a one big supercontinent called _______________. Wegener thought the continents must've once been connected because they look like they would fit together like pieces of a __________.
Pangea; puzzle
At a divergent plate boundary, what direction do the plates move?
Away from each other
At a convergent plate boundary, what direction do the plates move?
towards each other
At a transform plate boundary, what direction do the plates move?
the slide or rub past each other
What is the difference between magma and lava?
Magma is beneath the Earth's surface and lava is above the Earth's surface.
At what types of plate boundaries do earthquakes take place?
All of them!
Who proposed the continental drift hypothesis?
Alfred Wegener
How many different types of divergent plate boundaries are there?
2.
- Continental Divergent
- Oceanic Divergent
How many different types of convergent plate boundaries are there?
3.
- Oceanic-Oceanic Convergent
- Oceanic-Continental Convergent
- Continental-Continental Convergent
Crust is not _____________ or _____________ at a transform plate boundary.
created; destroyed (in no particular order)
What types of plate boundaries produce volcanoes?
Oceanic Divergent, Continental Divergent, Oceanic-Oceanic Convergent, Oceanic-Continental Convergent
Name the 3 types of faults discussed in this unit.
1. Reverse
2. Normal
3. Strike-Slip
This theory states that Earth’s crust and rigid upper mantle are broken into enormous slabs called plates. These plates interact with each other at areas called plate boundaries
The Theory of Plate Tectonics
What event (which supports the continental drift hypothesis) happens at an oceanic divergent plate boundary?
Seafloor Spreading
_____________ is the process where one plate is pushed underneath another. The more ________ plate always goes under the less _________ plate.
Subduction; dense; dense
In the Earth's mantel cooler magma falls and hotter magma rises. This constant flow of magma produces energy which aids in plate motion. What is this called?
Convection Current
Name the 3 types of volcanoes.
1. Cinder Cone
2. Shield
3. Composite or Strato-
The focus of an earthquake is the place in the Earth's lithosphere where the earthquake originates. What will cause more damage, a shallow focus or a deep focus? Why?
Shallow, there is less rock between the focus and the epicenter (surface) the absorb energy released from the earthquake.
Unfortunately, Wegener's hypothesis was initially rejected. It wasn't until many years after he died that Harry Hess proposed this missing piece of evidence which explains how oceanic crust is created and destroyed.
Seafloor Spreading
With the exception of a volcano, what type of landform is created at a continental divergent plate boundary?
Rift Valley
There are two landforms that are created by an oceanic-oceanic convergent plate boundary. What are they?
1. Deep Ocean Trench
2. Volcanic Island Arc
At subduction zones the denser, oceanic plate is being pulled down; because the plate has a high density gravity helps “pull” the rest of the plate down as well. What do we call this idea?
Slab Pull
The __________ (higher or lower) the viscosity, the _________ (faster or slower) the magma, the more ___________ the magma.
An earthquake which is rated a 5 on the Richter Scale is how many times larger than an earthquake rated a 4?
10xs larger
Pangea fit together like puzzle pieces. What were the other pieces of evidence Wegener used to support his continental drift hypothesis? (there are 4)
1. Similar rock layers found in different continents
2. Identical fossils found all around the world
3. Coal found in Antartica
4. Glacial till found near the equator
How was Iceland formed?
Answers may vary....
Iceland was formed along the Mid-Atlantic Ridge, an oceanic divergent plate boundary.
Magma rises from mantle, cool and forms rock Results in underwater mountains
((Mid-Atlantic Ridge – Mid-Ocean Ridge forming down the middle of the Atlantic Ocean))
The Pacific Ring of Fire is formed along what type of plate boundary? You must be specific.
Oceanic-Continental Convergent Plate Boundary
Along with convection currents, this mechanism helps plate motion as new rock is formed along divergent plate boundaries. Gravity plays a large role here as well.
Ridge Push
Name the 2 events we discussed that are associated with a volcanic eruption. Both of these events can cause immense and lasting damage.
Lahar and Pyroclastic Flow (or Pyroclastic Cloud)
According to the moment magnitude scale, an earthquake at a 3 releases ______ times the amount of energy as a 2.