Reading...
Play button
Play button
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;
52 Cards in this Set
- Front
- Back
|
magma
|
molten rock below earths surface
|
|
|
3 way silicate rock melts
|
-decompression
-addition of volatiles -addition of heat |
|
|
decompression
|
pressure is decreased
(divergent plate, continental rifts, hot spots) |
|
|
addition of volatiles
|
chemical compounds that lower the melting temp. of the rock
|
|
|
addition of heat
|
as magma rises heat is released to overlying rocks
|
|
|
magma is formed at...
|
plate boundaries
|
|
|
silica content high to low
|
Basaltic, andesitic, rhyotitic
|
|
|
viscosity
|
resistance to flow in fluids
|
|
|
viscosity determined by...
|
-silica content
-amount of dissolved gases -temperature |
|
|
lava tubes
|
where magma moves underground
|
|
|
where are shield volcanoes found
|
Hawaiian islands, Iceland
|
|
|
shield volcanoes
|
-largest
-non explosive -basaltic |
|
|
composite volcanoes
|
-cone shaped
-explosive and lava flows -andesite and rhyolite -responsible for most deaths |
|
|
where are composite volcanoes found
|
mount fuju japan, mount saint Helen and mount rainier
|
|
|
volcanic domes
|
-highly viscous
-horizontal blasts -highly explosive |
|
|
where are volcanic domes found
|
lassen peak and mono craters in cali
|
|
|
cinder cones
|
-built by tephra near vent
-small -nut to fist sized lava -common on flanks of larger volcanoes |
|
|
where are cinder cones found
|
central Mexico farm eruption
|
|
|
craters...
|
depressions at top of volcanoes that form during eruptions (1 mile diameter)
|
|
|
calders...
|
giant depressions ejecting magma. contain vents and hot springs (12 miles)
|
|
|
volcanic vent
|
opening through which lava and pyroclastic debris erupt
|
|
|
fissures
|
elongated cracks
|
|
|
hot springs
|
when groundwater comes into contact with hot rock
|
|
|
geysers
|
water in underground chambers that release steam and hot water
|
|
|
caldera eruptions
|
very rare, extremely violent, supervolcanoes
|
|
|
primary effects of volcanoes
|
lava flows, pyroclastic flows, gases, lateral blasts
|
|
|
secondary effects
|
debris flows, landslides, floods, fires, tsunamis
|
|
|
lahars
|
when loose volcanic ash is mixed with water
|
|
|
debris flows
|
when hot volcanic material melts snow and ice
|
|
|
mud flows
|
on the flanks of volcanoes. finer than debris
|
|
|
landslides
|
can cause affects far from source. can cause tsunamis
|
|
|
mt. st. helens
|
-may 18, 1980
-Washington state -57 killed -cascade volcanic eruption |
|
|
a tsunami is...
|
caused by a sudden vertical displacement of ocean water
"larger harbor wave" |
|
|
caused by
|
-earthquakes
-underwater landslides -volcanic flank collapse -submarine volcanic explosion |
|
|
runup
|
furthest horizontal and vertical distance the largest wave moves inland
|
|
|
edge waves
|
travel parallel to shore
|
|
|
highest areas at risk
|
-pacific ocean rim
-northern Mediterranean -northeastern Indian ocean |
|
|
major areas at risk for tusnamis
|
Cascadia, Chilean trench, japan
|
|
|
flooding
|
the natural process of overbank flow
|
|
|
runoff
|
surface drainage
|
|
|
drainage basin
|
area drained by a single stream
|
|
|
discharge
|
volume of water moving through a cross section of a river per unit time
|
|
|
the total load consist of...
|
-bed load
-suspended load -dissolved load |
|
|
bed load
|
materials that bounce or roll or slide along the bottom
|
|
|
suspended load
|
slit or clay particles that are carried in the water
|
|
|
dissolved load
|
materials carried as a chemical solution
|
|
|
braided channels
|
sand and gravel bars that divide and unite the main channel
(wide and shallow) |
|
|
meandering
|
migrate back and forth within a flood plain.
|
|
|
primary effects of flooding
|
-injured/loss of life
-property damage -erosion and deposition of sediment |
|
|
secondary effects
|
-short term pollution of water
-hunger and disease |
|
|
flood stage
|
elevation of water surface that will cause property damage
|
|
|
channelization
|
straightening, deepening, widening of existing stream channels
|
