Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
62 Cards in this Set
- Front
- Back
Where do volcanoes form?
|
Subduction zones, hot spots, spreading centers, plate edges
|
|
Why are volcanoes that form due to subduction andesitic and not basaltic?
|
Water carried with the plate lowers the melting point, so the continent melts as the magma rises, changing it's composition
|
|
What does SiO2 have to do with the type of eruption?
|
More SiO2=More explosive
|
|
Viscosity to do with an eruption?
|
More=more volatile
|
|
Dissovled gasses to do with an eruption?
|
More=more explosive because temp decreases=more solubility
|
|
Where do the most explosive volcanoes form?
|
Subduction zones
|
|
What makes volcanoes at subduction zones more explosive?
|
Lower melting point=higher SiO2, H2O content, viscosity, and gases
|
|
What three things generate an eruption?
|
Low Pressure, temperature rises, water content increases
|
|
6 types of volcanoes
|
Shield, Cinder/Scoria, Composite/Strato, Fissure/Flood, Lava dome, caldera
|
|
6 types of eruption styles
|
Vulcanian, Plinian, crater collapse, icelandic, hawaiian, stromboilian
|
|
Where is crater lake? How did it form?
|
Oregon, Mt. Mazma roof collapse
|
|
Volcanoes and eruption styles at spreading centers?
|
Fissure, flood. Stromboli and icelandic
|
|
Volcanoes and eruption styles at subduction zones?
|
Composite, vulcanian, plinian, caldera
|
|
3 cascade mountains and the one that has erupted the most in the past 4000 years
|
Mt Rainier, Shasta, Lassen Peak; St. Helens
|
|
How do we know the age of eruptions?
|
Radiocarbon dating of the surrounding trees
|
|
Describe the eruption of Mt. St. Helens
|
Earthquake caused a lahar, which released pressue and caused a lateral pyroclastic flow followed by a plinian eruption
|
|
Why are Shasta and Rainier eruptions so dangerous?
|
Lahars, high populations
|
|
Ways a volcano can kill you
|
Bombs, pyroclastic flow, lava flow, lahar, acid rain, landslide, gases
|
|
How does a P flow work and why is it so dangerous?
|
hot ash/gas/air flowing at high speeds
|
|
What makes a Nuee Ardente different from a pyroclastic flow?
|
It glows because it's incandescent
|
|
What causes a mass movement?
|
Gravity
|
|
External causes of slope failure
|
Material pulls away (tear away) or accumulates (pile up)
|
|
Internal causes of slope failure
|
weak material
water reduced cohesion Adverse Geologic Structure |
|
Inherently Weak Material
|
Small, book like structure
|
|
Water
|
Water fills pores and dissolves rocks or erodes loose material
|
|
Reduced Cohesion
|
Rock is compressed, then expands when compressor is lifted.
|
|
Adverse Geologic Structure
|
Ancient slip surfaces
Rock Layer Orientation Rock Weakness |
|
Mass Movement Triggers
|
Heavy Rain
Earthquakes Thawing of frozen ground Construction |
|
Quick Clay
|
clay flour+salt from glaciers. Gets lifted above sea level, water removes salt which makes it weak
|
|
Sink hole creation
|
Collapse into void, vertical downward movement, move as separate blocks
|
|
Maria
|
Sea on the moon
|
|
Why are few impacts visible on Earth?
|
erosion
|
|
Comets
|
orbit far past outer planets in the Oort Cloud
|
|
Asteroids
|
Inner planets/asteroid belt
|
|
Meteroide vs. meteor vs. meteroite
|
-ide=orbiting
-or=in atmosphere -ite=hit earth |
|
Rate of impact
|
100,000/24 hours
|
|
How are we protected?
|
The atmosphere acts like a solid
|
|
Where is meteor crater?
|
Arizona
|
|
Evidence for meteor impacts?
|
No local volcanoes, steep sides/rim, no sinkholes in area, high temp and pressue minerals found, fused sand
|
|
What is the K/T boundary?
|
Crutaceous/Tertiary iridium boundary
|
|
Life after an impact
|
Aftershocks
Wildfires Acid Rain Dust Global Warming Tsunami |
|
Crater forming process
|
Impact, melts, debris, vapor
|
|
Torino Scale
|
Rates possible impacts 0-10
|
|
Icelandic
|
Non-explosive, basalt, shield
|
|
Hawaiian
|
Non explosive, basalt, shield
|
|
Strombolian
|
Low explosions, basalt to slight andesite, scoria/cinder
|
|
Vulcanian
|
Moderately explosive, basalt to rhyolite, scoria and strato
|
|
Plinian
|
Highly explosive, andesite to rhyolite, strato
|
|
Caldera
|
Highly explosive, andesite to rhyolite, caldera
|
|
Shield/Flood Basalts
|
Low viscosity, low volatiles, large volume
|
|
Scoria
|
Low/med viscosity, med/high volatiles, small volume
|
|
Strato
|
med/high visco, med/high vol, large volume
|
|
Lava Dome
|
high visco, low vol, small volume
|
|
Caldera
|
high viscosity, high volit, large volume
|
|
Creep
|
Slow and dry
|
|
Falls
|
Fast and dry
|
|
Transitional Slide
|
rapid and moist
|
|
Rotational Slide
|
slow and moist
|
|
Mudflow
|
Rapid and saturated
|
|
Snow avalanche
|
Rapid and moist
|
|
Subsidence
|
Rapid and moist
|
|
Debris flow
|
Rapid and saturated
|