Earth skience Flashcards
1
Q
How do earthquakes occur
A
Plates try to slide through each other and get stuck,
Pressure builds up till the plates move again and, the pressured get released
2
Q
What are they evidence for continental drift
A
- Jigsaw puzzle fit
- Matching Geological/rock structures
- matching fossil /evidence
- Paleoglaction
- glacies in tropical areas
- coal deposition
3
Q
what Continental Drift Theory?
A
Continents are constantly moving & have been shifting
positions throughout history
4
Q
Who Posed the Continental Drift Theory?
A
Alfred Wegener in the late 1900’s
5
Q
How many main layers are there on earth?
A
4
6
Q
List all the layers
A
- crust -top layer of the earth
- Upper Mantle - is made of molten liquid
- Lower mantle - Solid made of dense rocks & minerals
- Outer core -its a liquid made of iron & nickel
- Inner core - center layer, liquid of nickel and iron Generating heat of radioactive decay (5000-6000c)
7
Q
How do you measure earthquakes?
A
Seismographs/ seismometers
*Seismograms are used to determine magnitude of the earthquake on the Richter scale
8
Q
Where do earthquakes occur?
A
Usually, occur at transforms or convergent boundaries
involve subduction
9
Q
What are types of seismic waves?
A
- Surface waves (L waves)
closest to the surface first to arrive
2.Body waves
Travels underground faster than surface waves - (P) Primary waves= travels fastest trough S,L
4.(S) Secondary Waves=detected second going through S
10
Q
What are the three types of volcanos
A
- Shield Volcanoes
* formed at a plate at a hotspot - Rift eruptions
* When Magma erupts between 2 diverging plates - Composite
* Formed at a subduction zone,edge of plate melts forming magma
