final study guide Flashcards
1
Q
climate change
A
- Increase over time of the average temperature of Earth’s atmosphere and oceans
- more contraversial
2
Q
Keeling curve
A
- shows us the CO2 concentration in atmosphere over time
- exponential increase
3
Q
global verticle energy balance
A
- some energy is trapped by our atmosphere, some leaves and bounces back
4
Q
climate proxies
A
- how we know about past climates
- Tree rings, rock formations, earth material chemical compositions, lake-floor sediments
5
Q
Greenhouse effect
A
- Earth absorbs sunlight, and some energy is given back to space, while some is absorbed - Necessary and natural, but it shouldn’t be enhanced with more gases in the atmosphere
6
Q
carbon cycle
A
- plate tectonics allow for flow of carbon throughout atmosphere
7
Q
three milankovitch cycles
A
- Eccentricity- circular or oval like
- Obliquity- shape of Earth’s orbit
- Precession- wobble that makes the Earth closer of further from the sun
8
Q
ideal combination for glacial development
A
a) circular orbits, which prevent close summer passes
b) small tilts (close to 22.1o) less summer solar heating
c) N.H. summer is farthest from the Sun, which needs a proper combination of the eccentricity and precession
9
Q
global ocean conveyor belt
A
- Heat is transferred through the water to the north towards Iceland
- Warm water exchanges heat with the cooler air becoming colder and saltier
- Near iceland, water becomes more dense (cool and salty) than the water below and sinks, flowing southward along the floor of the Atlantic
10
Q
role of volcanic eruptions
A
- Volcanic eruptions injecting sulfur-containing gases, [SO2 and H2S], into the stratosphere, leading to the formation of liquid sulfate aerosols
11
Q
what extreme weather events are we confident are impacted by climate change?
A
- need more research on things like hurricanes and extra-tropical cyclones, already are very confident on extreme heat and cold
12
Q
internal energy
A
- planet formation energy, gravitational energy, radioactive decay energy
13
Q
gravity
A
- fundamental force that draws matter together
14
Q
potential energy
A
- stored energy
- builds up and drives geological disasters
15
Q
crust
A
- overlies mantle
- light color
- low density rock
16
Q
lithosphere
A
- ridig solid rock
17
Q
asthenosphere
A
- fluid like (plastic rock)
18
Q
strain
A
- can change in form or size of a body due to external forces
19
Q
tension
A
- a state of stress that tends to pull the body apart
20
Q
compression
A
- a state of stress that causes a pushing together
21
Q
shear
A
- slides past eachother
22
Q
isostacy
A
- the less dense material floats on top of more dense material
- impoundment of water in Lake Mead behind Hoover Dam causes area to sink
23
Q
alfred Wegner
A
- came up with Theory of Continental Drift
- German meteorologist
- had 4 main evidences to support his theory that continents drifted apart
24
Q
the theory of continential drift 4 pieces of evidence
A
- fossil evidence- fossils found in different areas from where they are from (split by ocean)
- simmilarities across oceans- rock types, mountain ranges are geologically related but seperated by oceans
- coastlines look like they fit together
- paleoclimate glacial scarring found on rocks in tropical regions, coal in polar regions
25
plate tectonic theory
- Harry Hess
- used echo sounding surveys on the ocean floor and came up with the seafloor spreading theory
- convection currents that recycle magma
26
where are new rocks and old rocks?
- New rock in middle of ridge, old rock at trenches
27
convergent boundary
- push together
- can make mountain ranges and trenches
- subduction zones- one plate sinks below
- this happens when oceanic and continential plates collide
28
divergent boundary
- push apart
- pushes old rock away
- get earthquakes here
- ex: mid-atlantic ridge
29
transform boundary
- one subducts
- get volnacoes and mountains forming, trenches, deep earthquakes
- ex: san andreas fault
30
oceanic-continential convergence
- denser ocean sinks and subducts
- volcanoes
- trenches
- deep earthquakes
31
ring of fire
- area around pacific rim
- lots of volcanic activity here
32
continential-continential convergence
- Himalayan mountain range
- buckling and pushing
- none subduct
- earthquakes here
33
ocean-ocean convergence
- marianas trench
- one moves faster
34
earthquake
- vibrations are felt or recorded
- can be caused by a few things: volcanic activity, landslides, movement of the Earth across a fault (most common)
35
faults
- fracture in Earth across which the two sides move relative to each other
- are complex zones of breakage with irregular surfaces, many miles wide and long
36
elastic rebound theory
- Elastic strain accumulates across a fault
- When elastic strain energy exceeds the friction along the fault, a rupture occurs, and the rocks snap back into place, releasing stored energy
37
types of faults
- dip- slip fault
38
dip-slip fault
- dominated by vertical movement
- ore veins often form in fault zones, so
many mines are actually dug out along
- caused by pushing or pulling force
39
normal fault
- occurs when hangingwall moves
down relative to footwall, and zone of omission results
40
reverse fault
- occurs when hangingwall moves up relative to footwall, and zone of repetition results
41
strike-slip fault (right and left lateral faults)
- Dominated by horizontal movement
- When straddling a fault, if right-hand side moved towards you, it is a right-lateral fault
- When straddling a fault, if the left-hand side has moved towards you, it is a left-lateral fault
42
dip
- angle of inclination from horizontal of tilted layer
43
strike
- compass bearing of horizontal line in tilted layer
44
foreshocks
- smaller events preceeding the earthquakes
45
aftershocks
- smaller events after the earthquake
46
8 things that can form from fault lines
- Compression, uplift, hills
and mountains
- Extensions, down- dropping, basins and valleys
47
epicenter
- the point on the Earth's surface where the rupture happened
48
hypocenter or focus
- the point on the faultline underground where the rupture actually happened
49
Seismometer
- drum with a piece of paper on it and a pen
- mechanism on it that is sensitive to waves
- records how much energy comes in
- seismology is the study of earthquakes
- seismographs are the graphs that come from a seisometer
50
amplitude
- baseline to the height/crest
51
waveline
- crest to crust
52
period
- time between waves (1/frequency)
53
frequency
- number of waves in a second
54
body waves
- pass through entire planet
- could be primary (P) or secondary (S)
- most abundant at high frequencies
- most energetic closer to epicenter
55
surface waves
- move through surface only
- Love and Rayleigh type waves
- take longer to complete a cycle and they carry a significant amount of energy far from epicenter
56
Love and Rayleigh waves
- called L waves because they are long waves
- Love waves are side to side (horizontal)
- Rayleigh waves are like rolling waves (elliptical)
57
P waves
- primary (happen first)
- fastest to reach recording station
- can move through solid, liquid, and gas
- moves in compressional fashion (push-pull) like slinky
58
S waves
- second, slower to reach recording station
- shear waves
- side to side and up and down
- only travel through solids, but due to the shearing action, they cause severe damage
59
seismic waves
- defined by the way they displace the ground
60
locating earthquakes
- Requires at least 3 seismic stations
- Measure the time difference between P and S wave arrivals
- Convert time difference into distance
61
Richter scale
- deals with the amount of energy
- logrithmic
- For every 10-fold increase in the
amplitude of the recorded seismic wave,
the Richter magnitude increases one
number
62
Mercalli Intensity
- based on damage
63
moment magnitude
- Estimates the torque required to move rocks along a fault with a given resistance
64
predicting earthquakes
- hard to predict, but there are some precursors
- we know where they happen (plate boundaries)
65
societal effects of Earthquakes
- Quality of construction, preparedness of people, time of day
66
1886 Charleston Earthquake
- 60 deaths
- magnitude 7
67
Loma Prieta
- magnitude 7.5
- caused 63 deaths
- along San Andreas fault line
68
Nepal earthquake 2015
- 9,000 people died
- 8 magnitude
- triggered avalanche on Mt. Everest
69
direct effects from 1995 Kobe, Japan earthquake
- solely linked to deformation of ground near the fault itself (fault rupture)
- Many earthquakes do not rupture the surface
- Hyogo-Ken Nanbu rupture in rural island area
- Ground displaced just 3 meters
70
tsunamis
- means harbor wave in Japanese
- see them mostly in inlets or harbors
- different than tidal waves
71
crest
- top of the wave
72
trough
- lowest point of the wave
73
wave height
- distance between crest and trough
74
wavelength
- distance between two troughs or crests
75
rogue wave
- unusually tall wave
- Created as waves become synchronized
76
seiches
- Oscillating waves in enclosed body of water – sea, bay, lake, swimming pool
- Energy from strong winds or earthquake
77
causes of tsunamis
- earthquakes in deep ocean
- landslides
- volcanic eruption
- land that collapses into a body of water
78
why do these waves happen?
- Water is not compressible
- Cannot absorb fault-movement energy
- Water transmits energy throughout the
ocean in waves (drop a rock into a pond)
- Vertical-fault movements most commonly
cause tsunami
79
tsunami warning
- feel earthquake
- see a significant draw down in sea level
- hear the wave coming
80
what to do during a tsunami
- seek high ground
- go upstairs in a well built building
- climb a tree
81
costliest tsunami
- 2011, Fukushima Japan
- over 19,000 deaths
- caused by 9.0 magnitude earthquake
- more than $30 billion
- Caused a nuclear meltdown at 3 reactors
82
mass movements
- Large volumes of material move
downslope under the pull of gravity
- Triggered by earthquakes, volcanoes,
heavy rainfall
- annually cause $1.5 billion in damage
83
gravity
- pulls all the time
- Given time, gravity will pull all land into the
sea
- May be catastrophic or very-slowing
moving
84
Power behind agents of erosion
- rainfall, water flow, ice gliding, wind
blowing, waves breaking
85
causes of swelling
- Soil has a high percentage of open spaces,
porosity, water fills the voids, freezes &
expands, uplifting surface
- Soil rich in expandable minerals, i.e. clay,
absorbs water & expands
- Heating by the sun causes increased volume
86
causes for shrinking
- thawing
- drying
- cooling
87
creep
- very slow
- Best seen by looking at the objects on or affected by a slope
-Trees, telephone poles, stone walls
88
external processes (natural) for mass movement
- Steepening the slope (fault movements)
- Removing support from lower part of slope (stream or ocean wave erosion)
- Adding mass high on a slope (sediment
deposition)
89
human causes of mass movement
- Adding fill, creating hills to add views
- Remove material at base to widen or clear
roadways or to create a building lot
90
internal causes of mass movement
- Inherently weak material
- Water
- Decreasing cohesion
- Adverse geologic structures
91
water's influence on mass movement
- Weight
- Interaction with Clay
- Decreased cohesion of rocks
- Subsurface Erosion
- Pressure in pores of rocks and sediments
92
St Francis Dam
- Built in 1926
- Part of foundation in poorly bedded gravels, sands & muds held together by
clay
- Midnight March 12, 1928 base of the dam
failed
- Took 5 hours to travel to Pacific Ocean
- Killed 420 people
93
slow vs fast mass movements
- slow- property damage
- fast- property damage and injury or death
94
triggers for mass movement
- fires- removes vegetation, enhances surface runoff; can make the soil hydrophobic
- roads- natural support has been removed from hillslope
- storms- rainfall intensity and duration; saturated soils are weaker
- earthquakes
95
4 main types of movement
1. falls
2. flows
3. slides
4. subsides
96
falls
- free fall
- dominantly vertical downward movement
- move as seperate blocks
97
flows
- flow over landscape
- move as very viscous fluids
- turbulance within moving mass
- names: Loess flow, mudflow, earthflow, debris flow
98
slides
- Movements above one or more failure surfaces
- move as semisolid mass
- Curved concave- upward
- Nearly planar
99
subsides
- collapse into void
- dominantly vertical downard movement
- move as seperate blocks
100
yosemite
- 162,000 tons of granite rock
- Launched in the air for a 500 m drop
- Hit ground creating a Mag. 3+ earthquake
- 1 death, by tree falling in airblast
101
rotational slide
- Move downward and outward on top of
curved surfaces
- Slump – head moves downward and
rotates backward
- Scarp nearly vertical and unstable
- Toe of slump moves outward
102
translation slides
- Masses move down and out by sliding on surfaces of weakness
- Faults, clays, soft rocks slipping off hard rocks
- Sliding mass may deform and disintegrate
into debris slide
- Lateral spreading may occur where material fails and flows
103
point fermin
- Block Slide
- Layers of sandstone and clay-rich
mudstone
- January 1929, half-mile long block slide
- 5 acres of mass onland
- Slow moving – 1-2 years to slide
- Movement triggered by excess water from
yard irrigation
104
dangers of Vaiont, Italy
- Sedimentary rock layers folded into trough pattern,
causing beds to dip toward river
- Two sets of fractures split rocks apart
- Sliding on hills, historically
- Rock layers with seams of weak clays
- Limestone in hills with numerous caverns
- Increased water pressure at base after dam constructed
105
heavy rain in Vaiont, Italy
- Added weight onto unstable slopes
- 9 Oct 1963 10:41 pm, south wall of
reservoir failed
- Killed 3,000 people in 7 minutes
- Slide 1.8 km long and 1.6 km wide
106
snow avalanches
- Heavy snowfall on steep slopes, pull of
gravity
- Austria has 35 annual deaths from snow avalanches
107
submarine mass movements
- Volcanic Island Collapses into the sea
- Canary Islands
- Mega-tsunami
108
slow subsidence
- Removal of water or extraction of minerals
and oil
- Hawaii – as magma drains, land slumps
- Compaction of soils
- I.e. Mississippi Delta
- Long term – Venice, Italy
109
catastrophic subsidence
- Limestone sinkholes, SE US
- Extensive network of caverns
- Removal of groundwater or prolonged dry
spells can alter internal pressure of cave
- Alabama, 4,000 sinkholes have formed
since 1900
110
mitigation efforts for mass movements
- Install sensors on suspect terrane to measure
– pore water pressure
– Stretching and contraction of the soil
– Listen to noise of movements
- Measure precipitation and temperature
- Install drainage system to release groundwater
- Make the surface impermeable
- Grow some grass
111
volcanism
- Process through which magma rises
through Earth’s crust & extrudes onto
surface
- there are about 1500 active volcanoes on Earth
- 75% are in the ring of fire
112
extinct volcanoes
- not erupting, not likely to erupt
113
dormant volcanoes
- not erupting, has erupted in historic time or expected to erupt in future
114
active volcanoes
- is erupting or expected to in the near
future
115
how we understand volcanoes
1. Plate Tectonics
2. Magma (liquid rocks)
116
where are volcanoes?
- most are along plate boundaries and most others are along hot spots
117
hot spots
- plate moves over stationary mantle plume
- ex: Hawaii, Yellowstone
118
felsic magma
- sticky consistency
- mica and fledspar
119
mafic magma
- iron and magnesium
- basalt, "runny" type of magma
120
viscosity
- internal resistance to flow
- lower- more fluid-like
- higher- more resistant to movement
121
volatiles
- dissolved gases in magma that is like soda
- explodes
122
gases in volcanoes
- 50-80% water vapor
- CO2, N2, SO2, H2S
- release of toxic gases can cause fatalities
123
lava flows
- least dangerous hazard from volcanoes
- types: Pahoehoe and A'a
124
Pahoehoe
- smooth and ropy surface
125
A'a
- jagged irregular blocks
126
pyroclastic materials
- forms when gas release/explosion of viscous magma
- categorized by particle size
127
shield volcano
- wide, gently-sloping
- formed from low viscosity basaltic flows
- gentle eruptions
- common in ocean basins
- largest volcanic type
- ex: Mauna Loa
128
Cinder cones
- small, steep-sided volcanoes
- formed from pyroclastic materials
- single opening
- Often form on flanks or within calderas of
larger volcanoes
– Ex: Wizard Island
129
composite cones or stratovolcanoes
- made up of layers of pyroclastic materials and lava flows
- Lahars common
- intermediate in size and slope
- high viscosity, high volatiles, large volume
- ex: Mt. Fuji, Mt. Rainer
130
lava domes
- variable- Steep-sided, bulbous masses of
viscous lava
- Often found in composite volcanoes
- Usually felsic in composition
- Can be dangerous and can result in pyroclastic flow
- Ex: Mt St. Helens
131
eruptions
- release of internal heat
- Magma formed by melting existing rock
- Lowers pressure
- Raises temperature
- Increases water content
132
how eruption types are categorized
- based on solids, liquids, gases erupted
- can range from gentle flow, to more explosive gas eruptions, to solid eruptions
133
2010 eruptions of Eyjafjallajökull
- In Iceland
- phases: effusive to strombolian/vulcanian types
- ash cloud reached over 5 miles high
134
Mount Pinatubo
- an explosive type of eruption
- in 1992
- pyroclastic flows, blocks and bombs
135
Hawaiian-type eruptions
- Effusive, gentle
- Produces flowing lava
136
strombolian-type eruption
- Explosive, small-moderate eruptions on a
regular basis
- Produces some ash and bombs
137
vulcanian-type eruptions
- Explosive, moderate eruption size,
produces volcanic bombs and more ash
138
plinian-type eruptions
- Incredible gas-powered eruptions & pyroclastic material-ash
- Lots of Pumice
- Dangerous
Plinian-Type Eruptions
139
Giant Continental Calderas
- Huge negative land forms
- Lake Yellowstone in Wyoming
- Long Valley California
- Formed following rapid eruption of
pyroclasts
- Huge volumes of magma pour out in short
amounts of time – ultra-Plinian type
- Ex: Yellowstone National Park, WY
140
volcanic explosivity index
- gentle type: 1-3
- explosive type: 3-5
- catastrophic: anything above
141
volcanic tremors
- siesmic vibration
- minutes to days
142
can volcanoes produce different types of earthquakes?
- yes
143
USGS monitoring volcanoes
- they have people that respond (volcano hazards team) and monitor
