MIDTERM Flashcards
1
Q
Sustainability is engineering that meets the ______ __ ___ _______ without compromising the ________ __ ___ ________
A
needs of the present
viability of the future
2
Q
What is the triple bottom line
A
balance btw social, environmental and financial impacts
3
Q
explain physical geology
A
study of materials, processes on and below the Earth
4
Q
explain historical geology
A
origin of the Earth and development
5
Q
explain engineering geology
A
analysis of Earth history, processes and impact on human history
6
Q
what are the 4 spheres?
A
geosphere
hydrosphere
atmosphere
biosphere
7
Q
Ground water makes up ___% of all fresh water
A
31
8
Q
what is hydrology?
A
how water flows across the surface: water balance, flow channel systems
9
Q
who came up with catastrophism
A
James Usher
10
Q
what is catastrophism
A
the Earth’s landscapes (mountains, canyons) had been shaped primarily by great catastrophes
11
Q
who came up with uniformitatianism
A
James Hutton
12
Q
explain uniformitarianism
A
physical, chemical, biological laws that operate today here also operated in the geological past
THE PRESENT IS THE KEY TO THE PAST
13
Q
“forces that appear small could have great impact over longer periods of time”
catastrophism or uniformitarianism?
A
uniformitarianism
14
Q
how old is the earth approximately
A
4.6 million years old
15
Q
what is relative dating?
A
events are placed in proper sequence or order w/o knowing their age in years
16
Q
what is the law of superposition?
A
in layers of sedimentary rocks/lava flows, the youngest layer is on top and the oldest is on the bottom
17
Q
when did the Big Bang happen
A
approx 13.7 million years ago
18
Q
what is continental drift
who proposed it?
A
the continents moved about the face of the planet
Alfred Wegner
19
Q
example of continental drift
A
pangea
20
Q
the lithosphere consists of:
A
the crust and the upper most (brittle) part of the mantle, broken into smaller units called plates
21
Q
what is thin, rocky, oceanic or continental, made of granite and basalt?
A
crust
22
Q
mantle is:
A
solid, rocky shell that extends to a depth of 2900 km
23
Q
what is made of an iron-nickel alloy w minor amounts of oxygen, silicon and sulphur? It is also very dense
A
core
24
Q
the hydrosphere is a dynamic mass of _______, continually on the move, ___________, precipitating on the ______ and returning to the ocean again
A
water
evaporating
land
25
the atmosphere is a
life-giving, gaseous envelope surrounding the Earth, produces weather/climate
26
thin and tenuous is describing the:
atmosphere
27
biosphere?
all life on Earth
28
geosphere?
beneath the atmosphere and oceans
| continents w mountains and shields, directly reflect tectonic processes
29
what is paleomagnetism?
rocks that formed thousand/millions of years ago and recorded the location of the magnetic poles at that time, and are said to possess fossil magnetism
30
explain polar wandering?
the idea that the magnetic poles had migrated through time
| magnetic poles have gradually wandered due to continental drift
31
explain the sea floor spreading
- deep-ocean trenches are sites at which ocean crust is drawn back to the planet
- the older portions of the sea floor are gradually consumed as they descend into the mantle
32
due to sea floor spreading, continents have:
wandered
33
lithosphere is broken into how many plates?
7
34
divergent plate boundaries:
this plate boundary occurs where 2 plates move away from one another another at oceanic ridges where continents split, upwelling material
35
what do divergent plate boundaries create?
new ocean basins
36
convergent plate boundaries?
2 plates move together with descent of oceanic crust into mantle or collision of 2 continental plates
37
transform fault boundaries
where plates slip past each other, typically between 2 oceanic ridge segments
38
list proof that supports plate tectonic theory:
- continental rifts
- magnetic polar wandering paths
- mid-ocean ridges
- volcanic arcs
- ocean trenches
- volcanic islands associated w hot spot tracks
- increasing sediment age
- symmetrical pattern of magnetic intensities recorded in ocean floor rock
39
the tunnel boring machine Earth Pressure Balance is designed for :
clay but not for running sand
40
oceans accounts for what % of the earths water?
71%
41
how is earths system powered?
energy from the sun and from the heat from the earths core
42
explain the big bang theory
large explosion that sent all matter in the universe flying outwards at incredible speeds
43
what is the nebular hypothesis?
bodies in solar system evolved from solar nebula
44
the crust solid/rigid solid is composed of
silica materials
45
the mantle/plastic solid is composed of
magnesium/iron minerals
46
what are the 2 types of seismic waves
body
| surface
47
body wave
travel through earth's interior
| p and s
48
surface wave
travel on the earths surface
49
difference between a p and s wave
p: faster, travel through every material
s: can't travel through water
50
what is the rock cycle?
the loop that involves the processes by which one rock type changes to another
51
go through the rock cycle (5 steps):
- molten magma becomes igneous rock
- weathering creates sediments
- sediments lithify to sedimentary rocks
- burial and heat produce metamorphic rock
- add more heat and it repeats
52
greatest expanse of time
eon
53
phanerozoic
visible life
| the most recent eon, began just over 540 million years ago
54
a subdivision of an eon is:
an era
55
what are the eras of the phanerozoic eon
cenzoic (recent)
mesozoic (middle)
paleozoic (ancient)
56
eon-->era-->_______-->______
period
| enoch
57
how and why is isotope analysis and decay used?
igneous rocks contain uranium
uranium decays to lead at a defined rate
relative ratio of lead to uranium gives age of rock
58
radioactive decay
breakdown of an isotope
59
radiometric dating
calculate ages of rocks and minerals that contain particular isotopes
60
half-life
time required for half the parent radioactive nuclei in a sample to decay to daughter products
61
what is relative dating?
events are placed in their proper sequence or order w/o knowing their age in years
62
law of superposition
younger rocks are deposited over older rock layers
63
principle of fossil succession
fossil organisms success each other in a determinable order
64
principles of horizontality
layers of sediment originally horizontal
| flat rock layers have not been disturbed
65
principle of cross cutting relations
younger features cut across older features
66
what is an unconformity
break or gap in the rock record caused by erosion or nondeposition
67
index fossils
widespread geology and limited to a short span of geologic time
68
continents
prominent features are linear mountain belts
| shields
69
ocean basins
ocean ridge system
| deep ocean trenches
70
what is our current detailed understanding of the continents?
plate tectonics
71
what is a geomagnetic reversal?
earths magnetic field periodically reverses polarity
72
the magnetic field is preserved in?
cooling lava
73
dates when the polarity of the earths magnetism changes was determined by:
lava flows
74
the lithosphere consists of _________ mantle and overlying _______
it is broken into _______ ______
uppermost
crust
moving plates
75
what are the main methods for measuring plate motion used today?
- GPS tracking
- hot spots trace movement of Pacific plate relative to mantle
- average rate of motion calculated by the time interval between oldest and youngest volcanic structures
76
what drives the movement of the plates?
convection in the mantle
77
_________ plates move relative to one another at very _____ rates (plate tectonics)
lithospheric
| slow
78
where do divergent boundaries occur
mid-ocean ridges
| underneath rift valleys
79
subduction zone
consumption of crust into mantle
80
Isostasy is why the earth isn't _______
smooth
81
For any earth material to be considered a mineral it must exhibit the following characteristics (5):
1. occur naturally
2. solid at surface temperatures and pressure
3. possess an orderly internal structure, atoms must be arranged in a definite pattern
4. definite chemical composition, can vary w/in specific limits
5. USUALLY inorganic
82
Atoms are bonded to form a particular _________
structure
83
polymorphism is
when elements are able to join together in more than one type of geometric arrangement
ex. graphite and diamond
84
explain crystal habit:
shape
| external expression reflecting orderly internal arrangement of atoms
85
explain lustre:
quality of light reflected from the surface of a mineral crystal
metallic/non metallic
86
explain colour:
the colour lol
| obvious, but not always diagnostic due to alterations from impurities
87
explain streak:
colour of a mineral in its' powdered form
| obtained by rubbing mineral across piece of unglazed porcelin
88
explain hardness:
measure of minerals resistance to abrasion or scratching
89
explain cleavage:
tendency of a mineral to break along planes of weak bonding
90
explain fracture:
depending on the chemical structure of a mineral and the balance of strength in the bonds, it may break or fracture in a distinctive matter
91
explain specific gravity:
numbers representing the ratio of the weight of a mineral to the weight of an equal volume of water
92
define a rock:
a solid mass of minerals
93
define an element:
basic building blocks of minerals
94
atomic number
number of protons in an atom
95
atomic weight
approx. the total number of protons and neutrons in nucleus
96
list the other properties of minerals (3):
malleability, elasticity, striations
97
describe the silicates
most common mineral group
| Si-O tetrahedron
98
list some of the non silicates
```
oxides
hydroxides
sulphides
sulphates halides
carbonates
phosphates
```
99
2 oxides include:
magnetite
| hematite
100
2 hydroxides include:
limonite
| bauxite
101
2 sulphides include:
galena
| sphalerite
102
2 sulphates include:
gypsum
| anhydrite
103
2 native elements include:
gold
| copper
104
2 halites include:
halite
| fluorite
105
2 carbonates include:
calcite
| dolomite
106
2 phosphates include:
turquoise
| apatite
107
how and what are igneous rocks made from?
the cooling of molten lava
108
what does magma form from?
the partial melting of rocks inside the earth
109
lava is magma that:
reaches the surface of the earth
110
another word for extrusive is
volcanic
111
another word for intrusive is
plutonic
112
extrusive igneous rocks are rocks that
form when magma solidifies AT THE SURFACE
113
intrusive igenous rocks are rocks that
FORM AT DEPTH from magma that crystallizes slowly
114
what is a body of plutonic rock called?
a pluton
115
what are extrusive igneous features (3):
1. lava flows
2. fissure eruptions
3. volcanoes
116
what are intrusive igenous features (5):
1. batholiths
2. laccolith
3. sills
4. dykes
5. volcanic necks
117
what are the 3 components of magma?
melt, solids, volatiles
118
what is in the melt?
liquid portion of magma composed of mobile ions
119
what is in the solids?
silicate minerals that have already crystallized from the melt
120
what are the volatiles?
gases dissolved in the melt, water, carbon dioxide, sulphr dioxide which are confined by immense pressure exerted by the overlying rocks
make magma lighter so it rides
121
explain texture:
describes the overall appearance of a rock based on the size, shape and arrangement of its interlocking crystals
122
what are the 3 contributing factors to the texture of igneous rocks:
1. rate of cooling of magma
2. amount of silica present
3. amount of volatiles in the magma
123
geothermal gradient:
T increase in the Earth's upper crust, increasing with the depth
124
melting beings if:
CONFINING PRESSURE drops slightly
TEMP increases slightly
VOLATILES are introduced
125
what occurs when confining pressure drops?
decompression melting
126
cooling magma resulting in the systematic arrangement of ions into crystal structures is:
crystallization
127
magmatic differentiation:
formation of one or more secondary magmas from one parent
128
primary mafic magmas:
| also what is another name for them
originate from direct melting of mantle
| periodite
129
Andesitic and felsic rocks
found only w/in continents
| mixing of mafic magma and melted continental crust
130
felsic: _________ composition
granitic
131
mafic: _________ composition
basaltic
132
intermediate: _________ composition
andesitic
133
Ultramafic composition:
composed entirely of ferromagnesian silicates
134
glassy texture:
very rapid cooling of molten rock
| obsidian
135
aphanitic texture:
fine grained
rapid rate of cooling or magma
microscopic crystals
136
phaneritic texture:
coarse grained texture
slow cooling
larger crystals
137
pegmatitic texture:
very coarse grained texture
very slow cooling
forms in late stages of crystallization
138
poryphitic texture:
minerals form at different temperatures and rates
| large and small crystals intermixed
139
pyroclastic texture:
ejected during a violent volcanic eruption
140
factors that impact viscosity of magma:
1. dissolved gas increases fluidity
2. viscosity (silica content)/composition
3. temperature
141
eruption volumes
jets of hot ash-laden gases that evolve into buoyant plumes
142
Nuee ardente
fiery pyroclastic flow made of hot gases infused with ash and debris
race down the slopes of volcanos at up to 200 km/h
143
lahar
debris flow composed of mostly wet volcanic materials off steep sided/ flanks of volcanoes
144
fluid _______ lavas generally produce quiet eruptions, allowing the gases to _______ upwards and _______ with ease
mafic
migrate
escape
145
highly ________ lavas, also known as _________ or __________ produce more explosive eruptions
viscous
rhyolite
andesite
146
Shield volcano
produced by the accumulation of fluid mafic lavas
| broad, slightly domed (caldera)
147
Cinder Cones
ejected lava fragments that harden while in flight
148
Calderas
large collapse depressions having a more or less circular form
149
Fissure Eruptions
lead to immense buildups of basalt
150
Lava Domes
as thick silica-rich lavas flow/squeeze through the vent, might produce a steep-sided dome-shaped mass of congealed lava
151
weathering
breakdown of a rock at or near the Earths surface
152
mass wasting
transfer of rock and soil down slope by gravity
153
erosion
physical removal of material by water, wind, ice, etc.
154
mechanical weathering
breaking of rocks into smaller pieces by physical forces
chem comp of rock stays same
increases surface area
155
chemical weathering
chemical transformation of rock into one or more new compounds
breaks down components and internal structures of minerals
156
frost wedging
water in cracks freezes, expands and breaks the rock
| creates large piles of talus slopes
157
unloading (2 types)
sheeting: concentric slabs coming loose
| exfoliation dome
158
what causes unloading?
temperature cycling and stress relief
159
biologic activity (mech)
disintegration resulting from plants (roots), burrowing animals and humans
160
dissolution (chem)
soluble ions released from rock, aided by acidity
161
oxidation
chemical reaction in which an element loses electrons
| rusting
162
hydrolosis
H+ ion from water attacks and replaces other positive ions in the mineral, causing the crystal structure to collapse
163
rocks containing calcite or halite dissolve ________
readily
164
rocks containing silicate minerals are relatively _________
resistant
165
Differential weathering
since masses of rock do not weather uniformly, this results in many unusual and spectacular rock formations
166
what are the controls of soil formation?
```
parent material
time
climate
drainage
plants and animals
topography
```
167
pedalfer is a type of soil that is
accumulation of oxides and clays
organic-rich soil
temperate climates
168
pedocal is a type of soil that is
high accumulations of calcium carbonate
temperate grassland
low clay
169
laterite is a type of soild that is
wet and tropical climates
| concentrates iron and aluminum
170
clay as foundation is:
unpredictable
sensitive to disturbance
can fail catastrophically
171
silt as foundation is:
sensitive to frost and variations
172
sand as foundation is:
good
good drainage
sensitive to water content and density
173
gravel as foundation is:
rough and angular
| or rounded
174
talus slopes:
sections of rock that are wedged loose and may tumble into large piles
base of steep rock outcrops
175
infiltration capacity is controlled by:
```
intensity and duration of rainfall
slope of the land
soil texture
nature of the vegetative cover
prior wetness of the soil
```
176
what are the 2 types of water flow?
laminar
| turbulent
177
laminar flow is
slow, smooth channel
178
turbulent flow is
fast, rough channel
179
what are the 4 methods of flood control?
1. artificial levees
2. flood-control dams
3. channelization
4. floodplain management
180
waves derive ______ and __________ from wind
energy
| motion
181
wave height
distance btw trough and crest
182
wavelength
horizontal distance between crests
183
wave base is approx
1/2 wavelength
184
surf is
turbulent water created by breaking waves
185
tides are:
daily elevation of ocean surface
186
an incoming tidal current is known as a _______ current
flood
187
a seaward-moving tidal current is known as a _______ current
ebb
188
areas affected by tidal currents are called
tidal flats
189
an estuary is
an inlet of the sea formed at the mouths of streams
190
sedimentary rocks form from:
precipitation, sedimentation and accumulation of weathered rock material
191
diagenesis
all of the chemical, physical and biological changes that take place after sediments are deposited, but PRIOR TO METAMORPHISM
recrystallization and lithification
192
recrystallization
development or replacement of more stable minerals with less stable ones
193
lithification
when sediments are transferred into solid sedimentary rock by compaction and cementation
194
list the 5 types of sedimentary environments:
1. continental
2. transitional
3. marine
4. deep
5. sedimentary facies
195
continental sedimentary environment:
rivers and streams
glacial
wind
196
transitional sedimentary environment:
- Tidal flats
- Beaches
- Lagoons
- Deltas
197
marine sedimentary environment:
Shallow (to about 200 metres);
198
deep sedimentary environment:
Deeper than 200 m
199
sedimentary facies sedimentary environment:
each unit has characteristics reflecting a particular environment
different sediments often accumulate adjacent to one another at the same time
200
detrital sedimentary rocks
sediment transported as solid particles
201
chemical sedimentary rocks
chemical sediment that was in solution
202
organic rocks
from carbon rich tissues of once living things
203
strata or beds are
layers
204
bedding planes are
flat surfaces that separate strata
205
cross-bedding are
inclined layers
206
mudcracks are
shrinkage on exposure to air
207
ripple marks are
small waves of sand formed by moving water
208
remains or traces of prehistoric life preserved in sediment/sedimentary rock are known as
fossils
209
the 2 types of fossils are:
body
| trace
210
the three types of preservation fossils are:
Recrystallization
Petrification or Replacement
Mould – internal and external impressions
211
fissility means the rock splits into ....
| what rock does this? what rock doesn't?
thin layers
shale does
siltstone does not
212
describe sandstone
cement, sand sized particles
| transported by wind and water
213
types of sandstone (3)
quartz, arkose, wacke
214
conglomerate consist of ________ gravel
rounded
215
breccia is composed of large _______ particles
angular
216
evaporites:
rock salt
rock gypsum
potash
217
salt flats
dissolved material precipitated as
| white crust on ground
218
describe limestone
most abundant chemical rock
| composed mainly of calcite
219
metamorphism
changes in solid rock when a rock
is subjected to temperatures or pressures very
different from where they formed
220
true or false: for metamorphic rock, the parent rock can be any type?
true
221
the most important metamorphic agent is ______
heat
222
what do chemically active fluids do?
* Enhance migration of ions; act as catalysts
* Aid in re-crystallization of existing minerals
* Hydrated minerals lose water during heating
223
Uniform Confining pressure
applies forces equally in all
directions;
=denser metamorphic rocks
224
Directed pressure
which is unequal in different
directions,
=results in distortion
225
foliation
preferred orientation of platy minerals in a metamorphic rock
226
what are the three factors that influence foliation?
1. Rotation of platy and/or elongate mineral grains into a
new orientation
2. Changing the shape of equidimensional grains into elongate shapes aligned in the preferred orientation
3. Re-crystallization of minerals to form new grains growing in direction of preferred orientation
227
Contact metamorphism occurs when
rocks around an igneous body are cooked as magma invades the host
228
regional metamorphism
develops metamorphic rocks
229
describe slate
v. low grade
Very fine-grained
originally mudrocks and volcanic ash
flat, slaty, rock cleavage
230
Phyllite
Glossy sheen and wavy surfaces, wavy cleavage
Platy minerals not large enough to be identified with the
unaided eye
fine crystals of muscovite and chlorite
231
schist
medium to coarse grained
platy minerals dominate
schistosity
232
gneiss
```
Medium- to coarse-grained
Banded appearance
High-grade metamorphism
composed of light feldspar-rich bands with layers of dark
ferromagnesian minerals (gneiss texture)
```
233
greenschist
low grade
ferromagnesian minerals
foliation
green colour
234
amphibolite
higher grade than greenschist
chlorite converted to amphibole
less distinct foliation
235
granulite
very high grade
| amphiboles converted to pyroxene and garnets
236
rocks begin to melt at the ________ zone
transititon
237
what is a glacier
thick mass of ice that originates on land from the accumulation, compaction and recrystallization of snow
238
how does glacial ice form?
- snowflakes become granular snow
- air is forced out
- recrystallized into a denser mass, called a firn
- at 50m depth, firn fuses into a solid mass of interlocking crystals
239
internal deformation
occurs within ice
| under pressure, ice is plastic
240
basal slip
entire ice mass slipping along ground
241
meltwater
acts like a hydraulic jack, lifting ice to move over rocks
242
Soft bed deformation
Water-saturated sediment deform under glacier
243
Zone of fracture
-Upper 50 metres
-Tension causes crevasses
to form in brittle ice
244
rapid movements of a glacier called a
surge
245
Ice advances if accumulation _______ loss
exceeds
246
ice front “retreats” if ablation _______ or accumulation _________
increases
| decreases
247
a glacier forms in the:
zone of accumulation
248
there is a net loss to the glacier at:
zone of ablation
249
lower limit of the glacier is the:
equilibrium line
250
calving is the
breaking off of large pieces of ice into water
251
plucking
• Lifting and transport of rock
blocks (Erratics) at the base of
the glacier
252
abrasion
Rocks in ice acting like
sandpaper
Produces rock flour and glacial
striations
253
glacial trough
u shaped
| Transformed by deepening, widening & straightening
254
hanging valley
Former tributary valleys above the glacier
255
cirque
head of a glacier
256
tarn
lake in a cirque
257
arete
sharp ridge
258
horn
pyramid mountain
259
spur
triangular cliff
260
Roche moutonnées
asymmetric bedrock knobs with steep
| sides indicating direction of ice movement
261
fjord
water-filled glacial trough along a coast
262
Glacial drift
refers to all sediments of glacial origin
263
Till
Material deposited directly by glacial ice
264
Stratified drift
Sediments laid down by meltwater
265
what is a lateral moraine
ridges along the sides glaciers
266
what is a medial moraine
form where two glaciers merge
267
end moraine marks limit of ________
advance
268
Ground moraine
spreading under overriding ice
269
Deformation
changes in the original form and/or size of a rock body
270
force puts ___________ objects in motion or ________ the motions of moving bodeis
stationary
| changes
271
stress
force applied to a given area
272
strain
changes in the shape or size of a rock body caused by stress
273
what type of stress?
| -applied unequally from different directions
differential
274
what type of stress?
| -shortens a rock body
compressional
275
what type of stress?
| -elongates a rock body
tensional
276
what type of stress?
| -changes the shape of a rock body
shear
277
brittle fracture
low temps and pressures near the surface
278
ductile fracture
high temps and pressures deep: solid state flow
279
joints are fractures that
result from brittle deformation –typically no displacement
280
during crustal deformation, rocks are often bent into a series of wave-like undulations
this is called a
fold
281
what are the 4 parts of a fold?
| and describe
limbs - 2 sides of a fold
axis - crest of a fold
plunge - inclined axis
axial plane - divides a fold as symmetrically as possible
282
what are the 3 types of folds?
| and describe
Anticline–up-warped or arched rock layers
Syncline–down-warped or troughs of layers
domes and basins - 3D anticlines and synclines
283
what is a fault?
fractures in rocks along which appreciable displacement has taken place
284
```
hanging wall block moves down relative to the footwall
Accommodate lengthening (extension) of the crust
what type of fault?
```
normal
285
Graben is where
central block drops as plates separate
286
Horst are
raised blocks between graben
287
Dip-slip faults:
| Reverse(thrust) faults are:
hanging wall block moves up relative to footwall
| accommodate shortening of crust
288
dominant displacement is horizontal and parallel to the strike of the fault
what type of fault?
strike slip
289
stress =
force/area
290
linear strain=
change in length/ original length
291
elastic stiffness/elastic (Young’s) Modulus, E:
Resistance (Reaction Force) to Deformation BEFORE yield or failure
292
stress= __________ x strain
modulus
293
Shear Strength NOT dependent on normal pressure means:
cohesion
294
shear Strength FULLY dependent on normal pressure
friction
295
strength (in terms of failure)
Stress Level WHEN Failure or Yield Occurs
296
stiffness (in terms of failure)
Relationship between Stress & Strain BEFORE Yield
297
ductility (in terms of failure)
Relationship between Stress & Strain AFTER Yield
298
porosity is the
• Volume of Void Space Divided by the Total Volume
299
permeability is the
ability of fluid to flow through a porous solid
300
what are 4 ways to mitigate landslides?
Removal of Water
Movement of Slope Material
Restraints
Protection
301
removal of water means adding ________ __________
surface drainage
302
Lower Water Pressure= _________ in Effective Normal Stress = Greater ______ Strength
increase
| shear
303
mass wasting is
the downslope movement of rock and soil under the direct influence of gravity
304
what is the role of mass wasting?
geologic process that often follows weathering
| Combined effects of mass wasting and running water (erosion) produce stream
305
Gravity is the __________ force
controlling
306
what are other contributing factors to mass wasting? (4)
saturation of the material with water
Over-steepened slopes -unstable
Loss of anchoring vegetation
Earthquake ground vibration
307
explain the role of water in mass wasting (4)
saturation of the material with water
Water pressure reduces frictional resistance
Water interaction reduces particle cohesion
Water adds weigh
308
the stable slope angle is the
angle of repose
309
list and describe the 4 controls and triggers of mass wasting
over-steepened slopes: slope too steep for that type of material
removal of vegetation: root systems bind soil and regolith; leaves protect slope surface from raindrop
earthquakes as triggers: an dislodge large volumes of rock and unconsolidated material
liquefaction: water saturated surface materials behave as fluid-like masses that flow
310
explain the 3 types of motion in the mass wasting process
fall: detaches, forms talus slope
slide: material moves along a surface as a coherent mass)
flow: material viscously deforms
311
rockslides are when:
blocks of bedrock slide down a slope
312
a slump is a ___________ slide and is when
rotational
| downward sliding of a mass of rock or unconsolidated material as a unit along a curved surface
313
a debris flow is a
rapid event that involves a flow of soil and regolith with large amount of water
314
slow viscous movement on hillsides means (3)
waster saturates the soil and regolith
Prone to viscous (slow) flow but can be fast
Materials often rich in clay and silt
315
underwater “_________” are common and widespread geographically
landslides
316
earthquake is
the vibration of Earth produced by the rapid release of energy
317
what is the focus of an earthquake?
point of energy release -radiates in all directions from its source
318
Earthquakes generate _________ ______ that radiate throughout the earth
seismic waves
319
Following an earthquake, adjustments along a fault generate a series of smaller earthquakes referred to as ____________
aftershocks
320
small earthquakes often precede a major earthquake by days or even by as much as several years referred to as __________
foreshocks
321
seismology is the:
study of earthquake waves
322
seismographs are instruments that:
record seismic waves
323
travel through Earth’s interior (P and S)
| what kind of wave?
body
324
travel on the Earth’s surface
| what kind of wave
surface
325
what is the epicentre?
location on the surface above the focus
326
intensity:
measure of the degree of earthquake shaking at a given location
327
magnitude:
estimates the amount of energy released at the source of the earthquake
