Test 1 review Flashcards
1
Q
define disaster
A
hazardous events that occur over a limited time span in a defined geographic area
2
Q
define catastrophe
A
massive disaster that requires significant expenditure of money and time for recovery
3
Q
define recurrence interval
A
probability that an event of a given magnitude will occur at any time
4
Q
what is the recurrence interval equation
A
r=(n+1)/m
m=rank
n= number of observations
5
Q
what is a cyclic event
A
events that come at evenly spaced times
6
Q
are overlapping cycles cyclic
A
overlapping cycles make the resultant extremes non-cyclic
7
Q
how are event magnitude and frequency related
A
event magnitude and frequency are inversely related
8
Q
risk is a function of ?
A
risk is a function of (probability of occurrence)(cost of losses)
9
Q
structure and composition of tectonic plates
A
- mantle
- lithosphere
- athenosphere
10
Q
composition of the lithosphere
A
continental crust
oceanic crust
11
Q
describe the continental crust
A
20-70 km deep
granite
thick
less dense
12
Q
describe the oceanic crust
A
5-10km
mostly basalt
thin
really dense
13
Q
what are the three types of basic plate movement
A
- convergent margins
- divergent
- sliding
14
Q
describe rebound theory
earthquake cycles
A
- stored elastic strain
- earthquakes occur because of rebound/elastic strain
- stored elastic strain along subduction zone will generate earthquakes
- foreshocks and aftershocks
15
Q
seismic waves
A
body vs surface waves
16
Q
primary waves
A
compressional, fastest, parallel motion
17
Q
shear waves
A
only through solid material, perpendicular motion
18
Q
what are the two types of body waves
A
primary, shear
19
Q
what are the two types of surface waves
A
love, Rayleigh
20
Q
describe love waves
A
horizontal shaking
21
Q
describe Rayleigh waves
A
slow moving, elliptical motion, surface moves vertically
22
Q
what are the hazards associated with earthquakes
A
-generally result of the ground shaking or ground displacement caused by earthquakes
23
Q
where do the largest earthquakes occur
A
largest earthquakes happen in subduction zones
24
Q
why do the largest earthquakes occur in subduction zones
A
because of all the stores tension
25
what is thrust faulting created by
created by compression
26
what are joints and faulting
deformation of the earths crust
27
define folding
rocks and crust deforming
28
what are joints
rock fractures and there is no offset
29
what are faults
rock fractures and there is movement along the fracture
30
what percentage of earthquakes occur at plate boundaries
90%
31
what is deformation
the bending, breaking, and tilting of crust
32
what are the three types of stress
1) compressional
2) tensional
3) shear
33
describe compressional movement
plates move together (reverse/thrust)
34
describe tensional movement
plates move apart
| rift valleys
35
Describe shear movement
up and down movement
36
what creates a transform fault and where would you find one
shear movement, San Andreas fault
| North American and pacific plates
37
example of a fault not on a plate boundary
Denali fault
38
subaqueous landslides:
tsunami generators
39
what are the directional forces associated with normal faulting
extensional forces
40
what are the directional forces associated with thrust faults
compressional forces
41
give examples of normal faulting
North American plate being pulled away from eurasian plate
42
give examples of thrust faults
subduction zones, cascadiam JDF
43
when there is a collision between an oceanic and continental plate, what occurs?
subduction zone
44
what is the ring of fire
pacific plate
45
most volcanoes are near?
plate boundaries
46
what allows molten rock to reach earths surface
mid-oceanic ridges and subduction zones
47
difference between lava and magma
magma is molten rock, lava is magma on the earths surface
48
where can you find stratovolcanoes
subduction zones (Mt Hellens, fuji)
49
where can you find shield volcanoes
hot spots in the earths mantle (Hawaii)
50
where can you find calderas
spreading ridges or rift valleys (divergent plate boundaries)
ex) neuogango
51
what is volcanism
the surface expression of the forces within the earth, not limited to subduction zones or hotspots
52
what makes magma more explosive
explosive magma is typically at a cooler temperature and has more silica content
53
describe Rhyolte
super explosive, high silica content
54
describe Basalt
not really explosive, low silica content
55
shape of stratavolcanoes
cone shaped
56
how are stratavolcanes built
built from a combination of lava flows and pyroclastic deposits
57
what tectonic setting will you find stratovolcanoes
subduction zones
58
example of a stratovolcano
Mt Hellens
59
what are craters
depressions formed by explosion or collapse of volcano top
60
what are calderas
very large craters formed by violent explosions
61
what are vents
any opening for lava debris, can produce flood basalts
62
what re hot springs
hot rocks heat groundwater discharge at surface
63
what are geysers
groundwater boils, erupting steam at surface
64
what are resurgent calderas and super eruptions
very very large violent eruptions from super volcanoes, they produce calderas
65
describe Mount Fuji
strata volcano in a subduction zone
66
where is cakbuco found
subduction zone
67
describe shield volcanoes
largest volcanoes, built almost entirely of lava flows
| non explosive eruptions
68
what are shield volcanoes made up of
shield volcanoes are built almost entirely of lava flows
69
describe the eruptions of shield volcanoes
non explosive
70
example of a shield volcano
hawaii and iceland
71
where are shield volcanoes found
divergent plate boundaries
72
what are volcanic domes and lava lakes made of
they are made up of highly viscous rhyolite magma
73
describe the explosions of volcano domes and lava lakes
highly explosive due to the rhyolite magma
74
example of lava laker volcano dome
lassen peak, mono craters, Kati volcano is still errupting
75
where was the most recent caldera
Yellowstone
76
pahoehoe lava flow
basalt lava that has a stool or ropy surface
| typically advances in small lobes and tows that continually break out from a cooled crust
77
what triggers a pyroclastic flow
collapsing lava flow
78
A a lava flow
lava flows that have a rough cubby surface composed of broken lava blocks (clinkers)
79
where do divergent boundaries typically occur
divergent plate boundaries typically occur at mid-oceanic ridges (seafloor spreading)
80
what does seafloor spreading form
seafloor spreading forms a broad ridge, commonly with a central Rift Valley
81
example of divergent plate boundary
Iceland
82
describe what happens at am oceanic and continental convergent plate boundary
the denser oceanic plate is submerged under the continental plate
83
example of an oceanic and continental plate boundary
JDF and north America
84
describe what happens at an oceanic and oceanic convergent pate boundary
one plate goes beneath the other, creating a subduction zone and an arc-shaped chain of volcanoes
85
example of oceanic and oceanic convergent plate boundary
pacific and Philippine
86
describe what happens at a continental and continental convergent plate boundary
mountains
87
describe what happens at a transform plate boundary
plates slide horizontally past one another
88
example of a transform plate boundary
San Andreas Fault
89
What is a hot spot
partly molten materials are hit and buoyant enough to move up through the mantle into an overlying lithospheric plate
90
example of a hotspot
hawaii
91
what is the epicentre of an earthquake
point on the surface of earth directly above the fault rupture
92
what is the focus of an earthquake
location of the initial rupture along the fault
93
describe a strike slip fault
horizontal displacement
94
describe a dip slip fault
vertical displacement
95
what are the two body waves
primary and secondary
96
describe primary waves
fastest body wave, can travel through any material
97
describe secondary waves
can only travel through solid materials
98
what are the two types of surface waves
love ,Rayleigh
99
describe love waves
causes horizontal shaking
100
describe Rayleigh waves
elliptical motion, slower moving
101
describe a strike slip earthquake
occurs on transform faults, slides horizontally
102
describe a thrust earthquake
occur on large thrust faults
| largest on earth
103
describe normal earthquakes
common at divergent plate boundaries
104
describe shield volcanoes
largest volcanoes on earth
| non explosive eruptions q
105
example of a shield volcano
hawaii
106
describe stratovolcanoes
erupt less frequently but very explosive
107
example of a stratovolcano
Mount Fuji
108
describe a volcanic dome
steep sided mounds of lava that form around vents from the eruption
109
describe cinder cones
small volcanoes with a crater on top
110
What is a caldera
circular depressions that form during explosive ejection of magma
111
what is a volcanic vent
openings that things erupt from
