Earthquakes And Volcanos Flashcards
Focus
Where earthquake begins inside the Earth
Fault
Break in a body of rock along which one block slides relative to another
Epicenter
On Earth’s surface above focus
Elastic Rebound
Deform rock into original shape
Magnitude
Measurment of engery released
Intensity
Felt and damage done
Body wave
Seismic wave that moves through the earth
Surface wave
Seismic wave that travel through the surface of the earth
True or false: earthquakes can only occur along faults
True
True or false: earthquakes can only occur along techonic plates
False: can occur inside plates too
Primary waves
Moves rock in back in forth motion (push-pull)
Secondary waves
Moves rocks in side to side motion
What do surface waves do?
The damage
Two types of body waves
P (primary) and S (secondary) waves
Three types of volcanos
- Composite- formed from explosive and nonexplosive eruptions
- Sheild- built of layers of lava from nonexplosive eruptions
- Cinder Cone- made from pyroclastic material
How to make a stronger eruption
More water, more silica
Four types of pyroclastic material
- Volcanic bombs- large magma blobs
- Volcanic blocks- large pieces of solid rocks
- Lapilli- little rocks
- Volcanic Ash- most of mineral caused by fast expansion of gas
Four types of lava
- Pahoehoe- waxy
- Aa- sharp
- Pillow- underwater
- Blocky- jumbled heaps
Viscosity
How magma flows:
- Low viscosity, flows fast
- High viscosity, flows slow
Active
1 eruption in the last 10,000 years. Can erupt at anytime
Dormant
Hasn’t erupted in some time, but could
Extinct
Hasn’t erupted in a long time and isn’t expected to
Three types of volcanic landforms
- Craters- main vent of volcano
- Calderas- magma chamber empties
- Lava plateaus- lava flows
Explosive and Nonexplosive
- Explosive- explodes, rare, and cloud of hot debris
- Nonexplosive- oozes but never explodes, common, and lava fountain
Magma and lava
- Magma- inside earth
- Lava- on the surface
