Exam 1 Flashcards
(208 cards)
1
Q
universe is geocentric
A
heavenly bodies circle around a motionless central earth
2
Q
universe is heliocentric
A
sun centered universe, unpopular until renaissance
3
Q
Renaissance
A
new age discovery in 1400’s Europe, spawned new age of scientific exploration
4
Q
amount of visible galaxies
A
100 billion
5
Q
percent of mass in solar system of the sun
A
99.8%
6
Q
why isn’t pluto a planet
A
it doesn’t clear its neighborhood
7
Q
groups of planets
A
terrestrial and giants
8
Q
terrestrial planets
A
small, dense, rocky planets
9
Q
giant planets
A
large, low density
10
Q
exoplanets
A
planets found outside our solar system
11
Q
how to see exoplanets
A
kepler space telescope
12
Q
milky way contains about how many “earth” planets
A
14 billion
13
Q
moons
A
solid body locked in orbit around a planet, mercury and venus don’t have one
14
Q
asteroids
A
rocky or/ metallic objects that orbit the sun
15
Q
dwarf planets
A
rocky or/ icy bodies that are greater than asteroids
16
Q
comets
A
icy objects that orbit the sun beyond neptune
17
Q
Eratosthenes
A
calculated the circumference of earth in 200 b.c. by using shadows (39,300km)
18
Q
circumference of earth
A
40,008 km
19
Q
rotational velocity
A
1,674 km/h
20
Q
orbital velocity
A
108,000 km/h
21
Q
solar system velocity
A
720,000 km/h
22
Q
Doppler effect
A
waves compress with a relative motion, so galaxies are moving away from earth not closer
23
Q
compressed waves
A
shorter wavelength, higher frequency (blue light)
24
Q
relaxed waves
A
longer wavelength, lower frequency (red light)
25
light moving torward and observer
compresses (blue light)
26
light moving aways from an observer
expands (red light)
27
Expanding universe theory
the whole universe is expanding, galaxies farther from earth are moving faster than ones closer to us
28
big bang theory
all matter and energy compressed to a single point that exploded and continues to expands
29
The three criteria to call a celestial body a planet
orbit a star, roughly spherical shaped, and clear its neighborhood
30
nebulae
patchy clouds of atoms and molecules from expansion, rotating cause of mass
31
cause for collapse of gaseous nebulae
gravity
32
collapse resulted in increase in
temperature, density, and rate of rotation
33
star is born when
nuclear fusion starts
34
first generation stars
were massive but short lived (few million)
35
star explodes
supernova
36
big bang nucleosynthesis formed
He, H, L, Be, B
37
Elements are left over from the big bang
Helium and hydrogen
38
Nebular theory
The solar system started as a nebula, from the H and He left over from the big bang
39
NT nebula condenses into
protoplanetory disk from collapse
40
NT In nebular theory sun is born from
fusion reaction
41
NT dust in the rings
condenses into particles
42
NT particles coalesce to form
planetesimals
43
NT Planetesimals clumps into a
lumpy protoplanet, interior heats softens and forms a sphere
44
NT interior differentials into
nickel, iron core and strong silicate mantel
45
NT 5 billion years ago a mars planetoid collides with earth and they are
disintegrated
46
NT debris around earth forms
the moon
47
NT atmosphere develops from
volcanic gases
48
Interstellar space
region between stars, is a vacuum (vast) less than 1 atom/liter
49
astronomical units (AU)
93 million miles, distance from earth to sun
50
suns gravity felt
50,000 au away
51
layers of earth
interstellar space, Oort cloud, heliosphere, kuiper belt, interplanetary space, earths magnetic field
52
Oort cloud
populated by seeks, flakes, and balls of "ice" (water, carbon dioxide, ammonia, and methane), inner edge is 3,500 au from earth
53
heliosphere
200 au from the sun, outer reach of solar wind, outer edge of solar system
54
kuiper belt
icy band of objects, includes dwarf planets, comets originate here, inner edge is 30 au away
55
interplanetary space
denser than interstellar space, 5,000-100,000 atoms/liter
56
Van Allen belts
the solar wind that makes it create northern and southern lights
57
What are the steps for forming the solar system via nebular theory
nebula, planetory disc, planetismals, differentiation
58
nebular theory is just the formation of
earth and sun
59
Why does earth have a thick atmosphere
magnetosphere
60
Earths atmosphere is
N and O
61
The atmosphere here is denser than
interplanetary space
62
atmosphere is denser when
closer to the sun
63
atmospheric layers
troposphere, stratosphere, mesosphere, thermosphere
64
troposphere
lower mixing layer, weather here, temp decreases upward
65
stratosphere
no mixing occurs, temp increases upward
66
mesosphere
temp decreases upwards
67
thermosphere
outermost layer, temp increases upward
68
percent of dry and surface water
30% and 70%
69
91.2% of earth is comprised of these four elements
Fe, O, Si, and Mg
70
Elements that combine a variety of earth materials
organic chemicals, minerals, glasses, rocks, grains, sediment, metals, melts, volatiles
71
organic chemicals
carbon containing compounds
72
minerals
crystalline solids, silicate minerals are most common
73
glasses
noncrystalline solid
74
rocks
aggregate of minerals (igneous, metamorphic, and sedimentary)
75
grains
individual mineral crystals
76
sediment
accumulation of loose grains
77
metals
composed of metal ions
78
melts
solid materials are heated to liquid form
79
volatiles
materials that transform into gas
80
silicate rocks
minerals that contain silica (granite, gabbros,basalt, and peridotite
81
felsic
light and fluffy
82
mafic
dark and dense
83
granite
felsic rock with large crystals
84
gabbro
mafic rock with large crystals
85
basalt
mafic rock with small crystals
86
peridotite
ultramafic with large crystals
87
Land is usually
felsic
88
ocean land is usually
mafic
89
change with depth
change in temp and change in pressure
90
change in temp
heat is generated in earths interior causing increase
91
the geothermal gradient
temperature increase as we dig deeper
92
first key in understanding earths interior
density
93
study of earthquake gave
clues on layers of earth
94
seismic (surface) waves provide
insight on earth interior, velocity change with density,
95
continental crust is
thicker than oceanic crust
96
oceanic crust is
denser than continental crust
97
The base at the crust is called
the moho
98
The mantle
solid rock not magma, largest earth layer, 82% of earths volume
99
The core
iron rich sphere where seismic waves segregate two radically different parts
100
outer core flow generates
earths magnetic field
101
we also separate layers based on
rock strength
102
lithosphere crust and uppermost mantle
rigid/brittle (breaks rather than bends), broken into tectonic plates
103
Asthenosphere
upper mantle below the lithosphere, plastic/ductile (bends rather than breaks), flows as a soft solid
104
What evidences do we have that shows earth is layered
seismic waves, meteorites, plum-bob density, mantle rocks, high P-T experiments
105
How do we know the earths mantle is a solid and not a liquid
lack of tidal motion, all seismic waves can pass through the mantle
106
What are the two layers of earth, that are differentiated by there strength
the lithosphere and asthenosphere
107
Alfred Wegener
german meteorologist and polar explorer, wrote origins of oceans and continents in 1915 proposed theory continental drift, pangea
108
Wegener proposed
continents do change position over time, super continent existed
109
Wegeners evidence
fit of continents, past glaciations, climatic belts, fossil distribution, matching geologic units
110
Wegener could not explain
how of why continents moved
111
Wegener proposed continents moved by
earths spins
112
magnetic pole is not
reliable, but doesn't move outside of the arctic circle
113
compass points to
magnetic pole
114
declination
difference between magnetic and geographic poles
115
declination depends on
absolute position of 2 poles longitude
116
inclination
curved field lines cause a magnetic needle to tilt
117
inclination depends on
normal or reverse polarity, latitude
118
Paleomagnetism
study of magnetic fields of earths past
119
Iron minerals in rocks preserve information about
the magnetic field at the time rocks formed
120
Rock magnetism can be used to
trace continental movement
121
cold magma can be used to
trace magnetism during earth at the time
122
Where else can iron minerals be found
sedimentary rocks, because ground water can carry dissolved iron
123
Apparent polar wander
Proof that continents move
124
Layered basalts record
magnetic changes over time
125
inclination and declination
indicate change in position
126
each continent had a separate
polar wandering path,
127
epic sounding (sonar)
allowed rapid sea floor mapping
128
mid-ocean ridge
runs through the middle of every ocean
129
deep ocean trenches
occur near volcanic island charts
130
seamounts
poke up from the ocean floor
131
fracture zone
segment the mid-ocean ridge
132
ocean crust is covered by
sediment
133
sediment ocean crust is
thickest near the continents and thinnest near mid-ocean ridge
134
ocean crust rocks are
mafic (basalt and gabbro) no granite of metamorphic
135
heat flow is
much greater at mid ocean ridges
136
earthquakes occur in
deep ocean trenches, mid-ocean ridge axis, and fracture zones
137
some mid-ocean ridges have
a ridge axis
138
ridge axis
resemble a rift valley, could be a region of crustal spreading
139
Hess's essay of geopoetry
sediment thickness variation, difference in rocks, heat flow on sea floor, earthquake belts, and ridge axis
140
Hess's essay led to
idea of sea-floor spreading
141
sea-floor spreading
upwelling mantle erupts at the mid-ocean ridges, new crust moves away from ridges gathering sediments, sea-floor subducts back into mantle
142
sea floor is stripped with
positive and negative magnetic intensity
143
reversals intervals
crohns and subcrohns
144
crohns
longer intervals
145
subcrohns
shorter intervals
146
polarity reversals explain
magnetic anomaly stripes on sea floor
147
positive anomaly
sea floor rock normal polarity
148
negative anomaly
sea floor rock reversed polarity
149
sea floor spreading explains
symmetric stripes
150
what information can magnetic stripes on the sea floor tell us
rate of spreading, direction of spreading, earths magnetic field change, and age of ocean crust
151
plate tectonics
provides info: why we have types of rocks, distribution of earthquakes, volcanos,fossil plants and animals, completes continental drift theory
152
theory of plate tectonics evolved in
1960s
153
principle of buoyancy
described by archimedes, floatings solids displace water equal to their mass
154
an iceberg sinks until
the mass of water displaces is equal to the total mass of an iceberg
155
how many tectonic plates
about 15-20
156
plates move at a rate of
1-15 cm/year
157
tectonic plates size and shape
change throughout their history
158
plate interiors are
almost earthquake free
159
continental margins
where land meets ocean at active boundries
160
passive margins
far from plate boundries
161
passive margins crust thins
seaward
162
3 types of plate boundries
divergent, convergent, transform
163
divergent boundry
tectonic plates move apart
164
convergent boundry
tectonic plates move together, subduction occurs
165
transform boundry
tectonic plates slide sideways plate material is neither created or destroyed
166
divergent boundaries create
oceanic crust (sea floor spreading)
167
divergent boundary defined by
mid-ocean ridges
168
divergent boundary characterized by
shallow earthquakes and undersea volcanos
169
sea floor spreading progression early stage
forms a long thin ocean basin
170
sea floor spreading progression mid stage
ocean begins to widen, new sea floor, continents move further apart
171
sea floor spreading progression late stage
mature, wide ocean basin
172
in center of ridge
axial ridge valley
173
rising asthenosphere melts
forming magic magma that solidifies into oceanic crystal rock
174
pillow basalt
magma quenched at the sea floor
175
dikes
preserved magma conducts
176
gabbo
deeper magma
177
define plate tectonic theory
rigid lithospheric plates "float" on top of a plastic asthenospheric mantle, plates interact with one another to influence surface geology
178
where are divergent boundaries found
in the ocean
179
geological characteristics of divergent boundry
mid-ocean ridges, ridge axis, ocean volcanos, earthquakes
180
hot asthenosphere is at
base of the MOR
181
subducting plate is always
oceanic lithosphere
182
subduction destroys
oceanic crust
183
Wadati-Benioff zone
mark frictional contact and mineral transformation, earthquakes deepen away from trench
184
subduction is identified by surface features
deep ocean trenches, accretionary prisms, volcanic arcs, back-arc basins
185
accretionary prisms
deformed sediment wedge
186
back-arc basins
marginal sea behind a island arc, forms between an island arc and a continent
187
transform plate boundaries characterized by
shallow earthquakes, offsetting features on the earth surface, absence of volcanism
188
mid-ocean ridge axis's offset by
transform faults
189
triple junction
3 tectonic plates meet at a point, multiple boundary combinations occur, triple junctions migrate and change through time
190
Hot spots
plumes of deep mantle material independent of plate boundries
191
At which type of plate boundary would we expect to see a trench and a volcanic arc
convergent boundry
192
what geographic feature would we be able to see at a transform fault
no volcanos, offset features
193
How do plate boundaries form and die
continental rifting
194
continental rifting
process that occurs before a mid-ocean ridge is formed
195
continental rifting steps
lithosphere stretches and thins, brittle upper crust faults, ductile lower crust flows, asthenosphere rises and melts, magma erupts
196
continuation can create a
new mid-ocean ridge
197
continuation led to
break up pangea
198
example of continental rifting
east africa
199
plate collision boundries
2 continental crusts converging on each other
200
continental crust is too
buoyant to subduct and create mountains
201
plate tectonic collision involve
2 continents, a continent and island arc
202
collision sutures
convergent boundary
203
suture
boundary that once divided 2 plates is now incorporated into both plates, and the boundary becomes sewn together
204
old idea of plate motion
convection
205
2 driving forces for plates
ridge-push and slab pun
206
ridge-push
elevated MOR pushes lithosphere away
207
Slab-pull
gravity pulls a subducting plate downward
208
Absolute plate velocities may be mapped by
plotting plate motion from fixed point, measuring volcano ages/distance along hot spot track
