Tectonics Flashcards
1
Q
What are compressional waves?
A
- go through everything
- gases and liquids
- expansion/ compressions
- fast below/slow above = bends down
2
Q
what are transverse waves?
A
- s waves
- wiggle
- up and down
- can’t go through liquids
3
Q
why can’t transverse waves go through liquids?
A
no shear strength
4
Q
How do we know the Earth’s interior structure?
A
- compressional and transverse waves
- earthquake in one area with detectors on the other -> found shadow zones
5
Q
core
A
solid, dense
6
Q
out core
A
fluid, molten iron
7
Q
mantle
A
- solid and liquid
-moves slowly - transmits s waves
8
Q
asthenosphere
A
mushy and weak
9
Q
lithosphere and crust
A
solid
10
Q
what kinds of rocks do we find in the ocean lithosphere?
A
basalts and gabbros
11
Q
what kinds of rocks do we find in the continental lithosphere?
A
granites and rhyolites
12
Q
How did we discover tectonic plates?
A
- seismic energy behavior
- rock distributions
- paleo distribution
- magnetic field
13
Q
why does the earth have a magnetic field?
A
- chaotic convective motions in the liquid core
- when iron (magnetite) is hot, liquid minerals align with the magnetic field
- when iron (magnetite) is cold, align locks in (curie temperature)
14
Q
what is the curie temperature for basalt?
A
300
15
Q
How does the switching magnetic field contribute to the theory of tectonic plates?
A
- will point to magnetic north
- if turned or twisted will look like magnetic north is else where
