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geology test 4
Geology Test 4
324
Geology
Undergraduate 1
11/05/2020

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Term
The amount of ground water is ________ that of all rivers and lakes combined.
Definition
many times
Term
________ is the percentage of a rock or sediment that consists of void space.
Definition
Porosity
Term
_______ refers to the ability of a rock to transmit fluids.
Definition
Permeability
Term
Most ________ and ________ are both porous and permeable.
Definition
sandstone; conglomerate
Term
Shale has high porosity but poor permeability.
Definition
True
Term
Rocks with high porosity always have good permeability.
Definition
False
Term
An ________ rock is one that does not allow water to flow through it easily.
Definition
impermeable
Term
Which of the following earth materials would make the best aquifer?
Definition
sandstone
Term
The ________ is the zone above the water table.
Definition
vadose zone
Term
A ________ is a place where water flows naturally from rocks onto the ground surface.
Definition
spring
Term
A(n) ________ is a body of saturated rock or sediment through which water can move easily.
Definition
aquifer
Term
Which of the following earth materials would make the best aquitard?
Definition
shale
Term
The zone in the earth where all the pore spaces are completely filled with water is called the _______________.
Definition
saturated zone
Term
Ground water dripping in caves releases __________ , causing calcite to precipitate
Definition
carbon dioxide
Term
An area with many sinkholes and caves is said to have ________ topography.
Definition
karst
Term
Which of the following types of bedrock will most likely produce a karst area?
Definition
limestone
Term
________ are icicle-like pendants of calcite hanging from cave ceilings.
Definition
Stalactites
Term
Unsorted and unlayered rock debris carried or deposited by glaciers is called till.
Definition
true
Term
The compacted mass of granular snow, transitional between snow and ice, is called firn.
Definition
true
Term
The upper part of a glacier, the part with perennial snow and ice, is called the ________.
Definition
zone of accumulation
Term
The down-valley part of a glacier is the ________, where melting, evaporation, and calving take place.
Definition
zone of ablation
Term
The boundary between the zone of accumulation and the zone of ablation is an irregular line called the ________.
Definition
equilibrium line
Term
A(n) ________ -shaped valley (in cross section) is characteristic of glacial erosion.
Definition
U
Term
The grinding of rock against rock by a glacier produces a very fine sediment called ________.
Definition
rock flour
Term
Open fissures called ________ develop in the brittle surface ice of glaciers.
Definition
crevasses
Term
Sharp ridges called ________ separate adjacent glacially carved valleys.
Definition
arĂȘtes
Term
A large trunk glacier carves a deeper valley than smaller tributaries. After the glacier disappears the tributary valley remains as ________ high above the main valley.
Definition
a hanging valley
Term
A(n) ________ is a steep-sided half-bowl shaped recess carved at the head of a mountain glacial valley.
Definition
cirque
Term
________ moraines are elongate low mounds of till that form along the sides of valley glaciers.
Definition
Lateral
Term
A(n) ________ is the sharp peak that remains after cirques have cut back into a mountain on several sides.
Definition
horn
Term
Where tributary glaciers come together the adjacent lateral moraines join to form a ________ moraine.
Definition
medial
Term
A(n) ________ is a lake occupying a bedrock depression excavated by a glacier.
Definition
tarn
Term
Global sea level is higher during times of continental glaciation (ice age).
Definition
false
Term
A(n) ________ is a coastal inlet that is formed by a drowned glacial carved valley.
Definition
fiord
Term
________ stress results in a stretching or extension of material.
Definition
Tensional
Term
________ stress results in rocks being shortened or flattened.
Definition
Compressive
Term
If a deformed material recovers its original shape after stress is reduced, the behavior is ________.
Definition
elastic
Term
A rock that behaves in a(n) ________ manner will bend under stress and does not return to its original shape.
Definition
plastic
Term
Geologists sometimes find valuable ore deposits by studying the orientation of ________, fractures or cracks in a rock body along which no displacement has occurred.
Definition
joints
Term
What is the dip direction of Bed A?
Definition
Term
The amount of ground water is ________ that of all rivers and lakes combined.
Definition
many times
Term
________ is the percentage of a rock or sediment that consists of void space.
Definition
Porosity
Term
_______ refers to the ability of a rock to transmit fluids.
Definition
Permeability
Term
Most ________ and ________ are both porous and permeable.
Definition
sandstone; conglomerate
Term
Shale has high porosity but poor permeability.
Definition
True
Term
Rocks with high porosity always have good permeability.
Definition
False
Term
An ________ rock is one that does not allow water to flow through it easily.
Definition
impermeable
Term
Which of the following earth materials would make the best aquifer?
Definition
sandstone
Term
The ________ is the zone above the water table.
Definition
vadose zone
Term
A ________ is a place where water flows naturally from rocks onto the ground surface.
Definition
spring
Term
A(n) ________ is a body of saturated rock or sediment through which water can move easily.
Definition
aquifer
Term
Which of the following earth materials would make the best aquitard?
Definition
shale
Term
The zone in the earth where all the pore spaces are completely filled with water is called the _______________.
Definition
saturated zone
Term
Ground water dripping in caves releases __________ , causing calcite to precipitate
Definition
carbon dioxide
Term
An area with many sinkholes and caves is said to have ________ topography.
Definition
karst
Term
Which of the following types of bedrock will most likely produce a karst area?
Definition
limestone
Term
________ are icicle-like pendants of calcite hanging from cave ceilings.
Definition
Stalactites
Term
Unsorted and unlayered rock debris carried or deposited by glaciers is called till.
Definition
true
Term
The compacted mass of granular snow, transitional between snow and ice, is called firn.
Definition
true
Term
The upper part of a glacier, the part with perennial snow and ice, is called the ________.
Definition
zone of accumulation
Term
The down-valley part of a glacier is the ________, where melting, evaporation, and calving take place.
Definition
zone of ablation
Term
The boundary between the zone of accumulation and the zone of ablation is an irregular line called the ________.
Definition
equilibrium line
Term
A(n) ________ -shaped valley (in cross section) is characteristic of glacial erosion.
Definition
U
Term
The grinding of rock against rock by a glacier produces a very fine sediment called ________.
Definition
rock flour
Term
Open fissures called ________ develop in the brittle surface ice of glaciers.
Definition
crevasses
Term
Sharp ridges called ________ separate adjacent glacially carved valleys.
Definition
arĂȘtes
Term
A large trunk glacier carves a deeper valley than smaller tributaries. After the glacier disappears the tributary valley remains as ________ high above the main valley.
Definition
a hanging valley
Term
A(n) ________ is a steep-sided half-bowl shaped recess carved at the head of a mountain glacial valley.
Definition
cirque
Term
________ moraines are elongate low mounds of till that form along the sides of valley glaciers.
Definition
Lateral
Term
A(n) ________ is the sharp peak that remains after cirques have cut back into a mountain on several sides.
Definition
horn
Term
Where tributary glaciers come together the adjacent lateral moraines join to form a ________ moraine.
Definition
medial
Term
A(n) ________ is a lake occupying a bedrock depression excavated by a glacier.
Definition
tarn
Term
Global sea level is higher during times of continental glaciation (ice age).
Definition
false
Term
A(n) ________ is a coastal inlet that is formed by a drowned glacial carved valley.
Definition
fiord
Term
________ stress results in a stretching or extension of material.
Definition
Tensional
Term
________ stress results in rocks being shortened or flattened.
Definition
Compressive
Term
If a deformed material recovers its original shape after stress is reduced, the behavior is ________.
Definition
elastic
Term
A rock that behaves in a(n) ________ manner will bend under stress and does not return to its original shape.
Definition
plastic
Term
Geologists sometimes find valuable ore deposits by studying the orientation of ________, fractures or cracks in a rock body along which no displacement has occurred.
Definition
joints
Term
What is the dip direc[image]tion of Bed A?
Definition
west
Term
The side of the fault above the inclined fault surface is the ________.
Definition
hanging wall
Term
In a ________ fault the hanging wall block moves down relative to the footwall block.
Definition
normal
Term
A(n) ________ trap is one of the best structures for holding oil.
Definition
anticline
Term
________ are fractures in bedrock along which sliding movement has taken place.
Definition
Faults
Term
In cross section a structural basin looks like a ________.
Definition
bowl
Term
A(n) ________ is a structure in which beds dip away from a common central point, and the oldest rocks are found in the center.
Definition
dome
Term
Normal and reverse faults are the most common types of ________.
Definition
dip-slip faults
Term
In a normal fault, the hanging-wall block has moved ________ relative to the footwall block.
Definition
down
Term
In a ________ fault, the hanging-wall block moves up relative to the footwall block.
Definition
reverse
Term
What kind of fold is shown on the map? (bed 1 = oldest[image]
Definition
syncline
Term
What kind of fold is shown on the map? (bed 1 = oldest)[image]
Definition
structural dome
Term
Which block is the hanging wall?[image]
Definition
Block B
Term
What kind of fault is shown?[image]
Definition
normal
Term
What kind of fault is shown?
[image]
Definition
right-lateral
Term
The San Andreas Fault system can be described as ________.
Definition
right lateral strike-slip
Term
Earthquakes occur most commonly in the plate boundaries.
Definition
true
Term
The point within the earth where seismic waves first originate is the ________.
Definition
focus
Term
P-waves are compressional waves in which the rock vibrates back and forth parallel to the direction of wave propagation.
Definition
True
Term
Both P-waves and S-waves can pass through ________.
Definition
solid rock
Term
Which of the following seismic waves is the slowest
Definition
surface wave
Term
A ________ is the first wave to arrive at a recording station following an earthquake.
Definition
P-wave
Term
________ are seismic waves that travel through the Earth's interior, spreading out from the focus in all directions.
Definition
Body waves
Term
________ are earthquake waves that cause the most property damage.
Definition
Surface waves
Term
The time interval between the first arrival of P-waves and the first arrival of S-waves ________ with distance from the focus of an earthquake.
Definition
increases
Term
________ stations are the minimum needed to determine the location of an earthquake epicenter.
Definition
Three
Term
The Modified Mercalli Scale determines earthquake intensity, a measure of an earthquake's effect on people and buildings.
Definition
True
Term
A magnitude 4 earthquake on the Richter scale is how many times
stronger than a magnitude 2?
Definition
100
Term
A series of earthquakes that occurred near ________ in 1811-1812 were the most widely felt earthquakes to occur in recorded history.
Definition
New Madrid, Missouri
Term
A(n) ________ is a seismic sea wave.
Definition
tsunami
Term
________ is a measure of an earthquake's effect on people and buildings.
Definition
Intensity
Term
ground water
Definition
water that lies beneath the surface, filling pore spaces in rock
Term
ground water is ___ more abundant that surface water
Definition
60 times
Term
how much water on average reaches the surface of the earth and becomes ground water?
Definition
15 %
Term
the volume and flow of ground water depends on
Definition
porosity and permeability
Term
POROSITY
Definition
the percentage of pore spaces in a rock
Term
the more porosity a rock has, the more ____
Definition
water the rock can hold
Term
Porosity ranges from
Definition
0-80%
Term
Porosity depends on
Definition
rock or sediment type
Term
the ability of a liquid to move through pores or fractures in a rock
Definition
permeability
Term
Rocks need to be ______ for rock to be permeable
Definition
interconnected
Term
fluid flows easily through it
Definition
PERMEABLE ROCK
Term
no fluid moves through it
Definition
Impermeable Rock
Term
** rocks or sediment useful for extracting ground water must be
Definition
porous and permeable
Term
highly porous and permeable rock that is saturated with water
Definition
AQUIFER
Term
good aquifers are commonly
Definition
sand and gravel, (sandstone and conglomerate), or highly fractured rock
Term
relatively impermeable rock
Definition
AQUITARDS
Term
examples of aquitards are
Definition
shale, and crystalline rocks (granite schist)
Term
shal has ___ porosity but _____ permeability
Definition
high/low
Term
water percolates down through the ground and fills up pores
Definition
Distribution of ground water
Term
water stops at a dpeth of 5 to 10 km from the surface because what?
Definition
lithification (compaction and cementation) closes pores at these depths
Term
zone in which all pore spaces are filled with
Definition
SATURATED ZONE
Term
- top surface of the saturated zone
Definition
Water table
Term
zone above the saturated zone, which pores are partially filled with water
Definition
VADOSE ZONE
Term
in general water flow is controlled by
Definition
permeability and slope
Term
- the more permeable the rock
Definition
the faster water will move through it
Term
- the steeper the slope
Definition
the faster water will move through it
Term
water table usually
Definition
parallels the topography (flows downhill)
Term
are places where ground water flows to the surface, commonly where the water intersects the land surface
Definition
SPRINGS
Term
deep holes that are drilled or dug into a aquifer
Definition
Water wells
Term
addition of water to the saturated zone
Definition
RECHARGE
Term
** If the rate of water being removed faster than the recharge rate then the water table
Definition
will drop and wells will eventually go dry!!!!
Term
- excessive removal of water caused subsidence of the ground (
Definition
GROUND WATER MINING
Term
Groundwater easily polluted, hard and expensive to clean up
Definition
POLLUTION OF GROUND WATER
Term
- naturally formed underground chambers
Definition
CAVES
Term
Caves are commonly formed in
Definition
limestone
Term
icicle-like pendants of calcite hanging fro the top of a cave
Definition
STALACTITES
Term
cone-shaped masses of calcite formed on cave floors directly below stalactites
Definition
STALAGMITES
Term
- form when stalactites and stalagmites join together
Definition
COLUMNS
Term
from the collapse of a cave roof
-very common around Clarksville
Definition
Sink Holes
Term
area with many sinkholes and cave systems
unpredictable aquifers, commonly polluted
forms karst topography
Definition
Karst Area
Term
springs that have water temperatures warmer than body temperature
form near magma chambers (Yellowstone
form from deep water (2-3 km) moving to the surface
commonly precipitate silica and calcite at surface (temp and pressure reduction)
Definition
hot springs
Term
hot spring that periodically erupts water and steam
Definition
Geysers
Term
How geysers work
Definition
underground plumping above hot rocks prevent water from circulating-narrow, vertical chamber
Term
what are the 5 steps for a Geysers
Definition
water heat-up at bottom, requires temperatures > 100 C to boil (needs higher temperature to boil because of the pressure)2) when water is hot enough -bubbles form and move water out of chamber3) pressure is reduced, because of the water leaving the chamber, causing great quantities of water to turn instantly turn to steam4) steam forces water and steam to erupt out of the vent5) cold water fills up chamber, process repeats (minutes, hours, days, months
Term
a large, long-lasting mass of ice formed on land
-moves down hill because of gravity (think of glaciers as rivers of ice)-
forms any place, over a period of years, where more snow accumulates than melts
Definition
Glacier
Term
Glaciers are important because they are effective agents of
Definition
erosion, transportation, and depos
Term
** Form distinctively different geologic features from those produced by what?
Definition
running water
Term
What are the 2 types of glaciation?
Definition
Alpine and Continental
Term
glaciers found in mountainous region
(formed in valleys
Definition
Alpine Glaciation
Term
glaciers covering a large part of a continent (>50 km2)
glaciers not restricted to valleys, covers most mountains and valleys
Definition
Continental Glaciation
Term
compacted mass of granular snow, (has pore spaces between grains)-forms from compaction of snow
Definition
firn
Term
With more compaction, firn changes to what?
Definition
GLACIAL ICE(no pore spaces
Term
What are the 2 zones that glaciers can be divided into?
Definition
Zone of Accumulation and ablation
Term
upper part of a glacier where snow cover remains all year (more snow falls than melts
Definition
Accumulation
Term
lower part of the glacier where ice is lost by melting, evaporation, and calving
Definition
Ablation
Term
the breaking off of large chunks of ice when a glacier reaches a body of water(blocks float away as icebergs
Definition
Calving
Term
the boundary between the zone of accumulation and the zone of ablation(marks to lowest position were snow remains all ye
Definition
Equilibrium line
Term
if the total amount of snow retained by the glacier equals the amount of ice and water lost, then the ________ of the glacier will not advance or retreat
Definition
terminus (end)
Term
Although the terminus of the glacier is not moving, ice within the glacier
Definition
constantly moving from the zone of accumulation to the zone of ablation
Term
If snow accumulation is >> than water and ice lost -> ADVANCING GLACIER
Definition
glacier gets longer, terminus moves down slop
Term
If snow accumulation is << than water and ice lost -> RECEDING GLACIER
Definition
glacier gets shorter, terminus moves up slo
Term
because most glaciers today are receding earth has been
Definition
getting warmer
Term
what is the movement of valley glaciers
Definition
few mm-15 m/day ( varies during year)
Term
Valley Glaciers move faster in the ____
Definition
Center and top of the glacier
Term
Sliding of a glacier as a single body
(moves over Bedrock)
Definition
Basal Sliding
Term
movement that occurs within a glacier (does not move at base
Definition
plastic Flow
Term
top portion of glacier that rides passively over the plastic zone
Definition
Rigid Zone
Term
open fissures or cracks formed by different rates of movement of ice
Definition
Crevasses
Term
Crevasses commonly form where
Definition
on outside edges of curves and changes in slope
Term
ice moves downward and outward from a central high area towards the edges of the glacier
Definition
Continental glaciers
Term
WHat are the two way in which bedrock below the glaciers are eroded by basal sliding?
Definition
Abrasions and PLucking
Term
Abrasion
Definition
rocks at the bottom of a glacier scrap and grind away at the bedrock
Term
Abrasion produces
Definition
Striations and Rock Flour
Term
grooves and scratches in bed rock
(indicate direction of ice movement)
Definition
Striations
Term
very fine particles (mud-sized) formed from the grinding of bedrock-washes into stream and gives them a milky co
Definition
rock flour
Term
breaking loose of bedrock by melting and freezing of water in cracks
Definition
Plucking
Term
lANDSCAPES PRODUCED BY ALPINE GLACIATION (
Definition
Valley glaciers
Term
valley glaciers produce relatively straight
Definition
U shaped Valleys
Term
U-shaped valleys
Definition
width and strong abrasive power of glaciers carve edges of valleys making them straight and U-shaped
Term
Thicker the glacier, the more _____
Definition
the more vertical erosion it prod
Term
trunk (main) glacier erodes much deeper than____
Definition
smaller tributary glaciers
Term
when glacier disappears what forms?
Definition
Hanging valley
Term
steep-sided, half-bowl shaped depressions carved into a mountain at the head of a glacier
Definition
CIRQUE
Term
lake found in a cirque
Definition
Tarn
Term
sharp peak that remains after cirques cut back into a mountain on several side
Definition
Horn
Term
sharp ridges separating adjacent glacially carved valley
Definition
Aretes
Term
do not form rugged topography like alpine glaciers-form rounded topography-form grooved, striated bedrock and rounded elongated mounta
Definition
Landscapes formed by Continental glaciation
Term
Sediment produced by glaciation
Definition
angular, multi sized, unsorted
Term
unsorted, unlayered rock debris carried by glaciers
Definition
Till
Term
specific types of till deposits that occurs on a glacier orleft behind by a glacier
Definition
Moraine
Term
Types of Moraines
Definition
Lateral, Medial, End
Term
ridge like bodies of till along the sides of a valley glacier
Definition
Lateral
Term
ridge of till formed where two adjacent lateral moraines join and are carried down the glaciers
Definition
Medial
Term
crescent-shaped bodies of till that form at the terminus of a glacial
Definition
End
Term
period of geologic time when world temperatures were cold enough to produce extensive glaciatiom
Definition
Glacial Age or Ice Age
Term
Most recent Glacial Age ended
Definition
10000 years ago
Term
several cold and warm periods-cold periods (ice ages) temperatures were 5 C cooler than present-warm periods were slightly warmer than presen
Definition
During the Pleistocene Epoch (2 m.y to 10,000 years ag
Term
1/3 of the world's landmass was covered by ice!!!!-ice covered large parts of North America-see Figure 12.34 for ice coverage in North America-sea level dropped 130 m (water trapped in glaciers),-formed land bridge between North America and Asia-huge inland lakes formed (example Lake Bonnevi
Definition
Cold Periods
Term
formed extensive recession moraines in U.S. during retreat of ice (Figure 12.34)-sea level rose to near or above present-day levels-formed Fiords
Definition
Warm Periods
Term
coastal inlet that is a drowned glacially carved valley(formed during cold periods, get drowned during warm period)-common along the coasts of: Alaska, British Colombia, New Zealand, Norw
Definition
Fiord
Term
WHAT CAUSED THE EARTH TO GET SO COLD?
Definition
change in earth's orbit and tilt (earth is farther away, less solar energy)2) change in earth's atmosphere a) decrease CO2 (less greenhouse-effect, earth gets cold)b) volcanic eruption (blocks sun, earth gets cold
Term
concerns shape and deformation of rocks and the forces that cause the deformation
Definition
Structural Geology
Term
Tectonic forces move and deform parts of
Definition
Earth's Crust
Term
tectonic forces produce stress causing the rock to what?
Definition
Strain (deform by bending and breaking)
Term
applied force (pressure/unit area)
Definition
Stress
Term
the change in size (volume), or shape, or both while an object is under stress
Definition
strain
Term
What are the 3 types of stress?
Definition
Compressive,Tensional,Shear
Term
forces that tend to shorten a body
Definition
compressive
Term
forces that tend to elongate or pull-apart a body
Definition
Tensional
Term
forces that tend to cause parallel movements in a body, but in opposite directions to each other
Definition
Shear
Term
a body molded or bent while under stress and does not return to it's original shape after relaxation of stress
Definition
Plastic
Term
a deformed body will return to it's original shape after deforming stresses are relaxe
Definition
Elastic
Term
a body that fractures when under stress
Definition
Brittle
Term
what are the 3 types of strain?
Definition
plastic, Elastic, Brittle
Term
rocks near the surface of earth (<10 km depth) can behave
Definition
brittle or plastic to elastic if stress is applied very slowly
Term
rocks below the surface of earth (>10 km depth)
Definition
behave plastic to elastic
Term
a map that shows the distribution of rock types or formations in an area
Definition
Geologic map
Term
display of geologic features in a vertical section
Definition
geologic cross section
Term
Attitudes (direction and amount of tilt) of layers of rock can be describe in terms of
Definition
strike and dip
Term
the compass direction of a line formed by the intersection of an inclined plane (bedding plane) with a horizontal plane
Definition
strike
Term
has two parts (dip angle, dip direction)
Definition
dip
Term
is the acute angle measured downward from the horizontal plane to the bedding plane (ranges from 0-90 degrees
Definition
dip angle
Term
compass direction in which the dip is measure
Definition
dip direction
it is the direction a ball will roll down an inclin
Term
dip direction is always 90 degrees to strike direction
T/F
Definition
true
Term
bends in layered rock
Definition
folds
Term
is an arched-shaped fold
Definition
anticline
Term
is a trough-shaped fold
Definition
syncline
Term
line of maximum curvature of a fold
Definition
hinge line
Term
(rocks dip away or towards hinge line
T/F
Definition
true
Term
portion of a fold shared by an anticline and a syncline
Definition
Limb
Term
have the oldest beds along the hinge line and rocks dip away from hinge line
Definition
anticlines
Term
have the youngest beds along the hinge line and rocks dip towards the hinge
Definition
synclines
Term
are folds with dipping (not horizontal) hinge lines
Definition
Plunging folds
Term
a structure in which beds dip away from a central point
Definition
Structural Domes
Term
when are beds that are bend into an upside down bowl shape
Definition
Structural dome
Term
** oil and gas deposits are found
Definition
below the central portions of structural do
Term
a structure in which beds dip towards a central point
Definition
Structural Basin
Term
Ween are beds that are bend into a bowl shape
Definition
Structural Basin
Term
form when rocks break form stress, but have very little displacement (brittle strain)
Definition
Joints
Term
Joints are important for what type of projects?
Definition
construction for locating ground water and ore deposits
Term
fractures in bedrock along which movement has taken place (mm to 100's of km of movement
Definition
Faults
Term
are faults that have had movements in the last 10,000 ye
Definition
active faults
Term
faults are described in terms of their
Definition
direction of slippage
Term
What are the 3 type of faults
Definition
Dip, strike, oblique
Term
movement is parallel to the dip of the fault
Definition
Dip slip
Term
movement is parallel to the strike of the fault
Definition
Strike SLip
Term
faults that have both strike and dip slip components
Definition
oblique
Term
distinguished by relative movement of footwall block and hanging wall block
Definition
Dip slip faults
Term
What are the 2 types of dip split faults?
Definition
Normal and reverse
Term
underlying surface of an inclined fault plane
Definition
Footwall
Term
overlying surface of an inclined fault plane
Definition
Hanging Wall
Term
hanging wall block moves down relative to the footwall block
Definition
Normal Faults
Term
formed by horizontal tensional stress
Definition
Normal
Term
down dropped block bounded by normal faults
Definition
Graben
Term
rifts are grabens associated
Definition
diverging plat boundaries
Term
uplifted block bounded by normal faults
Definition
Horst
Term
hanging wall block move up relative to footwall block
Definition
Reverse Faults
Term
Reverse faults form from ?
Definition
Horizontal compressive stress
Term
Reverse faults are common in ?
Definition
Convergent plate margin areas
Term
What are the 2 types of strike slip faults
Definition
Left and RIght Lateral
Term
when looking across the fault, the opposite side moves to the le
Definition
Left Laterial
Term
when looking across the fault, the opposite side moves to the right
Definition
Right Lateral
Term
Strike SLip faults are common near
Definition
transform plate margins
Term
San Andreas fault in California is
Definition
Right lateral strike slip fault
Term
shaking of the ground caused by the sudden release of energy stored in rocks beneath the earth's surface
Definition
Earthquake
Term
Examples of sources of stored energy
Definition
stress from tectonic forces (major source)-stress from intrusion of magma(minor, small earthquakes
Term
Why are earthquakes important
Definition
kills thousands of people every year
-tremendous property damage
-Clarksville is located near the most active earthquake area in the eastern half of the U. S
Term
Whats a cause of earthquakes?
Definition
ELASTIC REBOUND THEORY -
Term
rocks stressed by tectonic forces, stored elastic strain until the strength of the rock is exceeded (F
Definition
Elastic Rebound THeory
Term
when strength is exceeded, rocks breaks (along a fault) causing what?
Definition
releasing the stored energy in the form of seismic waves
Term
earthquakes mostly occur where?
Definition
upper, cooler portions of the earth where the rocks behave brittlely
Term
energy waves produced during an earthquake
Definition
Seismic Waves
Term
point in the earth where seismic waves originate endpoint of initial movement on a fault
Definition
Focus
Term
point on the earth's surface directly above the focus
Definition
Epicenter
Term
intersection of the fault with the surface of the earth
Definition
Fault Trace
Term
cliff formed by faulting
Definition
Fault Scarp
Term
What are the two main types of seismic waves?
Definition
Body Waves and Surface Waves
Term
seismic waves that travel through the earth away from the focus
Definition
Body Waves
Term
What are the two types of body waves?
Definition
P waves and S waves
Term
a compression wave that vibrates parallel to the direction of wave propagation
Definition
P Wave ( Primary)
Term
What is the fastest type of wave?
Definition
P wave at 4-7km second
Term
What type of wave can travel through solid and fluid material ?
Definition
P wave
Term
a wave that vibrates perpendicular to the direction of wave propagation (moves likes waves generated by a shaking rope
Definition
S wave (Secondary)
Term
What waves can only travel through a solid?
Definition
S wave
Term
What wave can indicate that outer core of earth is liquid?
Definition
S wave
Term
seismic waves that travel along the earth away from the epicenter
Definition
Surface Wave
Term
What is the slowest type of wave?
Definition
Surface wave
Term
what wave can produce ground movement and last longer causing more property damage than body waves
Definition
Surface
Term
Seismic waves are measured by a
Definition
Seismometer
Term
Seismometer's readings are recorded on a
Definition
Seismogram
Term
The further away a seismometer is from the epicenter, the______
Definition
Later the earthquake will be recorded
Term
time between the arrival of P and S wave gets _____
Definition
Longer with distance from earthquake
Term
From the length of time between the arrival of P and S waves you can determine distance from
Definition
Seismometer to earthquake
Term
Can determine exact position by using ____ seismometers
Definition
Three seperate
Term
Strength of earthquakes are measured in what two ways?
Definition
INtensity and magnitude
Term
masurement of an earthquakes effect on people and buildings
Definition
Intensity
Term
To measure intensity you would use a
Definition
Modified Mercalli Scale
Term
measurement of the energy released during an earthquake
Definition
Magnitude
Term
What are the 2 scales of magnitude
Definition
Richter and Moment
Term
measurement of surface motion (based on how fast the ground shakes
Definition
Richter Magnitude
Term
For magnitude what is the most commonly reported scale
Definition
Richter
Term
logarithmic scale, higher the number the stronger the earthquake
T/F
Definition
True
ten magnitude 2 earthquakes equals one magnitude 3 earthquake
Term
a new scale that measures the amount of energy released during an earthquake more accurately
Definition
Moment Magnitude
Term
Moment magnitude does what for the richter scale
Definition
Indicates each division for the scale and equals about a 30 fold increase in energy released
Term
Most earthquakes located in western U.S are ____
Definition
Tectonically active
Term
Most earthquakes in the world occur along plate boundaries T/F
Definition
true
Term
structures fall down -concrete and brick structure collapse easier than wood frame building
Definition
Ground Motion
Term
gas mains break, water mains break most of San Francisco 1906 earthquake damage was from fire
Definition
Fire
Term
Landslides are a common effect of an earthquake? t/F
Definition
True
Term
water saturated soil or sediment turns from a solid to a liquid from earthquake shaking
Definition
liquefaction
Term
vertical or horizontal movement of the earth along a fault-seldom exceeds 25 fee
Definition
Rupture of Earth Surface
Term
large ocean waves produced by an earthquake
very dangerous (can hit occur many 100's of kilometers away from earthquake)-
moves at speeds up to 450 miles/hour
-can create waves 50 -100 feet high along shore (278 ft record height)
Definition
Tsunamis
Term
small earthquakes that follow the main shock
Definition
Aftershocks
Term
small earthquakes that precede the main shock -not all big earthquakes have foreshocks
Definition
Foreshocks
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