Exam 3 Flashcards
1
Q
2 types of igneous rocks
A
extrusive and intrusive
2
Q
extrusive igneous rocks
A
volcanic
3
Q
intrusive igneous rocks
A
plutonic
4
Q
What do igneous rocks erupt?
A
lava and pyroclasts
5
Q
Fragmented volcanic rock ejected upward explosively
A
pyroclasts
6
Q
pulverized magma also a type of pyroclasts
A
ash
7
Q
molten rock in the earth
A
magma
8
Q
magma that reaches the surface
A
lava
9
Q
3 parts of characteristics of magmas
A
- Composition
- Viscosity
- Volcanic Gases
10
Q
Compositions
A
what something is made up of
11
Q
What is the overall composition of magmas?
A
made of silica
12
Q
Silica minerals are made of
A
silicon and oxygen
13
Q
What are the 3 types of compositions of magmas?
A
- Mafic
- Felsic
- Intermediate
14
Q
Mafic is ____ poor
A
silica
15
Q
Why is mafic dense
A
because of minerals
16
Q
Felsic is what type of composition
A
silica rich
17
Q
Felsic has a high amount of
A
gases
18
Q
Felsic rocks
A
rhyolites
19
Q
light, less dense rock
A
rhyolites
20
Q
Intermediate silica content
A
intermediate
21
Q
rocks of intermediate composition
A
andesites
22
Q
Andesites are found in
A
the Andes
23
Q
Where are andesites abundant
A
over subduction zones
24
Q
The resistance to flow
A
viscosity
25
Viscosity is controlle by
silica content and temperature
26
Higher temp = ___ viscosity
less
27
Something that doesn't resist flow
has a low viscosity
28
Mafic magma viscosity
silica poor, very hot = low viscosity
29
Felsic and Intermediate magmas viscosity
silica rich
| cooler = higher viscosity resists moving
30
2 most abundant volcanic gases
H2O and CO2
31
Once an eruption starts the pressure is _____ and drive the explosion _____.
lowered; upward
32
Why do you want to avoid dead tree areas in Mammoth?
volcanic gases are escaping to the surface and you could breath CO2
33
Lake Nyos is a lake on top of what
active volcano structure
34
Everything killed without a volcanic eruption
lake nyos
35
Magmas: Hot, silica poor and low viscosity
Mafic
36
Result of a mafic magma
fluid eruption and lava flow
37
Magma: Silica rich, cooler, high viscosity
Felsic and Intermediate magmas
38
Result of felsic and intermediate magmas
explosive eruption with pryoclasts
39
Pressure decrease
mid-ocean ridges
40
water added
subduction zones
41
heat added
hot spots
42
What is important to allow plates to move?
Lower pressure
43
What is a catalyst for melting rocks?
Water
44
Where are the majority of land volcanos?
at subduction zones, in the pacific rim of fire
45
Which kinds of eruptions are the most hazardous?
Pyroclastic Eruptions
46
Opening of a volcanic edifice (1km or less)
Crater
47
Opening of a volcanic edifice, larger than 1km
Caldera
48
Volcanic building connected to magma chamber below crater
volcanic edifice
49
Mt. Pinatubo is an example of what
caldera
50
Phillipines and Mt. Tambora are examples of what
Calderas
51
One possible cause of the information of a caldera
summit collapse
52
Volcano: Broad dome, gentle slope and very large
Shield
53
Volcano: Composition of basaltic lava flows
shield
54
Volcano: fluid magmas with low viscosity and low silica
Shield
55
Volcano: Basaltic, mafic and largest
Shield
56
2 Examples of shield volcanos
Hawaii and Iceland
57
Hawaii is a
hot spot
58
Iceland is a
mid-ocean ridge
59
Volcano: Steep, tall and layered
strato
60
Volcano: composition of andesite lava flows
strato
61
Volcano: pyroclastic and lava flows
Strato
62
Volcano: high viscosity and high silica
Strato
63
Volcano: Andesites, rhyolites, basalts
Strato
64
2 nd largest volcano
Strato
65
Mt. St. Helens is an example of
strato volcano
66
Mt. Vesuvius is an example of
strato volcano
67
Mt. Rainer and Mt. Fuji are examples of
strato volcano
68
Mt. Hood in Oregon and Mt. Shasta are examples of
strato volcanos
69
Land slides and toxic gases are hazards associated with
Strato Volcanos
70
Lava dome collapse and acid rain are hazards associate with
Strato volcanos
71
Lava flows and ash falls are hazards associated with
Strato Volcanos
72
Type of flows associated with Strato Volcanos
pyroclastic and mudflow (lahar)
73
Crater Lake in oregon collapsed
inwards (summit collapse)
74
Crater Lake in Oregon is approximately
10km
75
Crater lake in Oregon is filled with
water
76
Is Crater Lake in Oregon active or inactive?
active
77
What type of cone is Crater Lake in Oregon
Cinder cone
78
Pacific Northwest volcanoes are a result of the ______ and occurs at ______
Juan de Fuca Plate; Subduction Zones
79
The shape of volcanoes is controlled by what it
spits out
80
Cone that is steep, small and short lived
Cinder cone
81
Cinder Cone is a ______ pyroclasts composition
basaltic
82
Cinder cones occur adjacent with
other big volcanoes
83
Viscosity of cinder cone
viscous
84
From largest to smallest volcanoes
Shield --> Strato --> Cinder
85
What kind of cone was a Paricutin eruption, Mexico?
Cinder cone
86
What kind of flow is paricutin eruption, mexico?
lava flows
87
Is Paricutin eruption, mexico active?
not active anymore
88
Volcanic Explosivity Index is from what to what numbers?
0 to 8
89
Powerful vertical ejection of pyroclasts, gas
plinian
90
Most explosive eruption
Plinian
91
Plinian eruptions VEI range
3 to 8
92
Where are plinian eruptions common over
strata volcanoes
93
What type of eruption has a small eruption of pyroclasts?
Strombian
94
What type of eruption is a fluid basaltic lava flows?
Hawaiian
95
Yellowstone is so big that we call it
a collapse caldera
96
Yellowstone is a result from
a continental hotspot
97
Why are geysers erupting in Yellowstone?
because there is so much heat
98
When yellowstone emptys its magma all of it goes out then collapses downwards then refills
catastrophic summit collapse
99
Anak Krakatau, Indonesia
- cinder cone
| - pyroclast type eruptions
100
Crater lake
- cinder cone inside a strato peak
| - still active
101
Santorini
- Lost city of Atlantis
| - Caldera
102
Today Atlantis looks like
a crater lake
103
City on top of active volcano
Phira
104
Here lavas are really fluid, hot and low viscosity
Hawaii
105
example of mafic composition
Hawaii
106
How many big shield volcanos in hawaii
5
107
Most active volcano in the world
Kilauea
108
What des Mauna Loa have?
calderas because they are over 1km in width
109
Dormant and going to be extinct, it moved from the source of lava
Mauna Kea
110
Why is Mauna Kea not active?
because it has stepped out of the hot spot
111
2 shielf Volcanos in Hawaii
- Kilauea
| - Mauna Loa
112
In the future there will be a new island in the south called?
Loihi
113
Hawaii has what types of volcanos
Strato, shield and calderas
114
2 deadliest volcanic hazards?
pyroclastic flows and volcanic mud flows
115
When the column decides to collapse outwards this causes
pyroclastic flow
116
Scalding avalanche of ash and toxic, expanding gases
pyroclastic flow
117
2 ways to make a pyroclastic flow
dome and column collapse
118
Viscous lava that grows on the inside the crater of volcano
Dome
119
Dome collapse is a cause of
pyroclastic flows
120
Dome collapses are quite
unpredictable
121
When a pyroclastic column starts to go up and then comes down
Column collapse
122
Full plinian column comes down and incinerates everything in its path
Column collapse
123
Which are the most deadly volcanoes?
Strato
124
Examples of Strato pyroclastic flows? (4)
- Mt. St. Helens
- Mt. Pineatube
- Mt. Montserrar
- Mt. Mayon
125
A flood flow of ash
Volcanic mud flow or lahar
126
Rapid flood of pyroclasts and water
lahar
127
- Rainfall and loose ash
- Melting of snow and ash
- Breakout of a crater lake
- Rivers and lakes
Causes of Lahar
128
In Mt. St. Helens the ____ plate is ____ under the ____ plate
- Juan de Fuca
- Subducting
- North American
129
In Cascadia subduction one the volcanoes are young or old?
quite young
130
Recurrence interval of Mt. St. Helens
around 200 years
131
The eruption of Mt. St. Helens was similar to
500x the force of the Hiroshima explosion bomb
132
- Swarms of EQs
- Steam/ ash explosions
- M= 5 EQ
- VEI = 5
- Gigantic landslide
- steam blast
- mudflows
- plinian column with pyroclastic flows
Precursor Events of Mt. St. Helens
133
Death toll of Mt. St. Helens
57 people
134
What remains after explosion
a caldera
135
Why did the Mt. St. Helens volcano not catastrophically collapse?
because the Magma chamber did not fully empty
| and this is common event as opposed to summits collapse
136
What hazard can a dome produce?
a pyroclastic flow
137
In Nevado del Ruiz what plates are involved?
Nazca plate is subducting under the South American Plate
138
_____ overcomes friction in a mass waste
gravity
139
Tectonic forces ____ uplift the ground and are seen at subduction zones
uplift
140
Where do Tectonic forces occur?
in the Cascades on the East Coast
141
Solana Beach
is a disaster waiting to happen because coastal erosion is occurring
142
1. Soft loose sediment and silts erode very rapidly and that is how the beaches form in CA
2. People are building on these cliffs
3. People carve out notches and ruin the base. Do not stand at base of cliff
Hazards in Solana Beach
143
What are the 5 factors of mass wasting?
1. Water content
2. Slope angle
3. Geological
4. Human
5. Vegetation
144
excess water increases slope failures
water content
145
Steep slopes increase slope failures
slope angle
146
til of rocks, types of rocks, clay, faults
Geological
147
Overloading of slopes, artificial fill, excavation of highways and deforestation
Human
148
Decreases slope failures
Vegetation
149
Water is ____ from soil in vegetation. They provide ___and ___. The only thing that is good
- removed
- cushions
- cover
150
3 types of mass wasting
- Falls
- Slides
- Flows
151
Free fall of rocks; very rapid and common in mountains
Rock fall
152
movement of rock down a failure
Slides
153
Slump (rotational slide)
curved surface, weak sediments, small
154
Rockslide
planar surface, more coherent
155
La Jolla is a
slump
156
Most fluid and it results from very heavy rainstorms
Mud flow
157
Volcanic mud flow; comes from rain, lake, river
Lahar
158
Largest, fastest and most deadly flow, also very rare. Encompass huge areas
Debris Flow
159
Slow moving, not very harmful but can lead to other types of mass wasting
Creep
160
Triggering Events for mass wasting
1. Rainstorms
2. Earthquakes
3. Volcanoes
161
Product of a large earthquake off shore
Yungay, Peru
162
Nazca plate is sliding under the south american plate
Yungay Peru
163
Yungary, Peru is on a
convergent boundary
164
Yungary, Peru was triggered by
subduction quake of M=7.7
165
Yungary Peru was a compositie event of
rock fall and flow
