Earth's Planetary Structure Flashcards
1
Q
What is Earth’s interior composed of?
A
- primarily solids
- molten portions
2
Q
How do we know the composition of the Earth?
A
indirect and direct means
3
Q
What do DIRECT means refer to?
A
- mining and drilling
- can only examine a small portion of the Earth
4
Q
What do INDIRECT means refer to?
A
- seismic waves
- seismograph
5
Q
What are the two types of seismic waves?
A
- primary waves (P)
- secondary waves (S)
6
Q
What are PRIMARY waves?
A
- arrives first
- straight and stretched apart
- travels through all states of matter
7
Q
What are SECONDARY waves?
A
- arrives second
- wavy
- travels through solids
8
Q
What are the 3 layers of the Earth?
A
- core
- mantle
- crust
9
Q
What is the CORE?
A
- 1/3 of Earth’s mass
- solidified core due to pressure
- molten outer core due to temperature
- iron and nickel
10
Q
What is the MANTLE?
A
- largest interior zone
- less dense than the core
- upper and lower
11
Q
What is the UPPER MANTLE composed of?
A
- asthenosphere
- lithosphere
- mohorovicic
12
Q
What is the ASTHENOSPHERE?
A
- bottom layer of the mantle
- plastic-like fluid
- responsible for plate tectonics
13
Q
What is the LITHOSPHERE?
A
top layer made of cold, dense rock
14
Q
What is the MOHOROVICIC DISCONTINUITY?
A
a boundary between the crust and mantle where the velocity of seismic waves decrease
15
Q
What is the CRUST?
A
- 1% of the Earth’s mass
- lithosphere exterior
