Earth Flashcards
General questions about Earth, its composition and structure, Analysis with regards to Atmosphere, Sun and Solar System (141 cards)
1
Q
- Mean radius of Earth
- (Volumetric) Mean radius
A
6371 km
3981 miles
2
Q
Average distance from sun
A
149.6 million km
93 million miles
3
Q
Closest to Sun (perihelion)
A
147.1 million km
(91.5 million miles)
about Jan. 3
4
Q
Farthest from Sun (aphelion)
A
152.1 million km
(94.5 million) miles
about July 4
5
Q
Rotates on axis in how many hours?
A
24
6
Q
revolves around Sun in how many days?
A
365.2564 days
7
Q
Diameter: through equator is?
A
12756.26 km (7928 miles)
8
Q
Diameter through poles?
A
12713.5 km (7899 miles)
9
Q
Difference in diameter through equator and poles is due to?
A
centrifugal force of earth’s rotation (at equator, centrifugal force is about 3/1000 as much as Earth’s gravity)
10
Q
Surface area of Earth is?
A
510 million square km (198 million) square miles, of which about a quarter is land.
11
Q
Mass of Earth?
A
- 5.97x1024 kg or 6,000,000,000,000,000,000,000 (6x1021) metric tons
- 5.97
12
Q
Of the Earth’s mass: 1/3 is?
A
Core
13
Q
Of the Earth’s mass: 2/3 is?
A
Mantle
14
Q
Of the Earth’s mass: 4/1000 is?
A
The Crust
15
Q
Of the Earth’s mass: 2/10,000 is?
A
The Oceans
16
Q
Of the Earth’s mass: 1/1,000,000
A
Atmosphere
17
Q
Of the Earth’s mass: 1/100,000
A
Ice-caps
18
Q
Of Earth’s atmosphere, Nitrogen is how many percent?
A
79%
19
Q
Of Earth’s atmosphere, Oxygen is how many percent?
A
20%
20
Q
Of Earth’s atmosphere, Argon is how many percent?
A
1%
21
Q
Average density of Planet Earth is?
A
5.5 g/cm3
5514 kg/m3
22
Q
Types of seismic waves are:
A
a. Surface Waves
b. Body Waves
23
Q
Surface Waves are also called
A
L-waves or Longitudinal waves
24
Q
Epicentre
A
Point on Earth’s surface that is directly above the ‘Hypo-center’ or focus (the point where an earthquake or under-ground explosion originates)
25
Slowest seismic waves
L-waves
26
Velocity of L-waves is?
2.5 km/sec
27
Kinds of Body waves?
a. Push waves or compressional waves (p-waves)
| b. Shear or shock waves (s-waves)
28
Which kind of body waves can travel through liquids?
P-waves
29
As 'p-waves' propagate, in which direction do they move material in their path?
Parallel to the direction of their movement
30
Fastest Seismic waves?
P-waves
31
Velocity of P-waves?
6-7 km/sec
32
What causes p-waves?
-The energy released when the rocks break up or slip near the focus causes p-waves
-Compression of the rock volume
(pushing and thereby reducing)
33
In which direction do the s-waves displace objects in their path?
- Perpendicular to the direction of their motion
| - Right angle to the direction of their motion
34
Velocity of s-waves?
3.5 km/sec
35
Volume (1010 km3)
108.321
36
Equatorial radius (km)
6378 km
| 3963 miles
37
Polar radius (km)
6356 km
| 3949 miles
38
Difference between Equatorial and polar radius in km?
22
39
Difference between Equatorial and polar radius in miles?
14
40
Core radius (km) of earth
3485
41
Ellipticity (Flattening)
0.00335
42
Mean density (kg/m3)
5514
43
Surface gravity (m/s2)
9.798
44
Surface acceleration (m/s2)
9.780
45
Escape velocity (km/s)
11.186
46
Black-body temperature (K)
254.3
47
Topographic range (km)
20
48
Topography
: the art or science of making maps that show the height, shape, etc., of the land in a particular area
: the features (such as mountains and rivers) in an area of land
49
orbital velocity of earth
29.8 km/s
50
Orbital inclination (degrees)
0.0
51
Orbital eccentricity
0.017
52
Unit for eccentricity
There are no units for eccentricity
53
Axial tilt (degrees)
23.4
54
Axial tilt definition
In astronomy, axial tilt, known to astronomers as obliquity, is the angle between an object's rotational axis and its orbital axis, or, equivalently, the angle between its equatorial plane and orbital plane. It differs from orbital inclination.
55
Mean temperature of earth
15 degreed C
56
Surface pressure (bars)
1
57
Which planets do not have known global magnetic fields?
Venus, Mars and Pluto
58
Mohorovicic Discontinuity year
1909
59
Lithosphere Depth
0-60 km
60
Crust Depth
0-35
61
Upper Mantle Depth
35-60
62
Mantle Depth
35-2890 (2883)
63
Asthenosphere Depth
100-700
64
Outer Core Depth
2890-5100 (5140)
65
Inner Core
5100-6378 (6371)
66
Oceanic lithosphere density
2.9 g/cm3
67
Continental lithosphere density
2.7 g/cm3
68
Crust density
2.2 - 2.9 g/cm3
69
Upper Mantle density
3.4 - 4.4 g/cm3
70
Mantle density
3. 4 - 5.6 g/cm3
| 4. 5 g/cm3 (avg)
71
Lithosphere density
3.0 - 3.3 g/cm3
72
Oceanic Crust density
3.0 - 3.3 g/cm3
73
Continental Crust density
2.7 - 3.0 (avg: 2.6)
74
Crust thickness
30 km
75
Upper mantle thickness
720 km
76
Lower mantle
2171 km
77
Outer Core
2259 km
78
Inner Core
1221 km
79
Crust: Types of rocks
Silicic rocks, Andesite, Basalt at base
80
Upper Mantle: Types of rocks
Peridotite, eclogite, olivine, spinel, garnet, pyroxene, perovskite, oxides
81
Lower Mantle: Types of rocks
Magnesium and Silicon Oxides
82
Outer Core: Types of rocks
Iron + Oxygen, Sulfer, Nickel alloy
83
Inner Core: Types of rocks
Iron + Oxygen, Sulfer, Nickel alloy
84
Atmosphere is what percentage of Earths mass?
1/1,000,000
85
Oceans are what percentage of Earths mass?
2/10,000
86
Crust is what percentage of Earths mass?
1/250
87
Mantle is what percentage of earths mass?
2/3
88
Core is what percentage of earths mass?
- 1/3
| - 30%
89
Nitrogen is what percentage of atmosphere?
79%
90
Oxygen is what percentage of atmosphere?
20%
91
Argon is what percentage of atmosphere?
1%
92
Core is what percentage of earths volume?
16%
93
Average density of Core
15 g/cm3 (maybe 13 g/cm3)
94
How thick is core as a whole?
3500 km
95
Inner core radius
1200 km
96
Temperature of Inner core
4000- 5500 degrees C
97
How thick is outer core
2260 km
98
What percentage is Mantle of earths mass?
70%
99
What percentage is Mantle of earths volume?
80%
100
How thick is mantle in km
2866 km
101
Temperature of mantle
100-3200 degrees C
102
Average density of mantle
4.5 g/cm3
103
Outer core density
9.9 - 12.2 g/cm3
104
Inner core density
12.6 - 13.0 g/cm3
105
Oceanic lithosphere in km
100 km thick beneath oceans
106
Continental lithosphere in km
150 km thick beneath continents
107
Asthenosphere in km
100-700 km
108
Mesosphere in km
700 -2900 km
| most of the mantle
109
What percentage of earths mass is Crust?
0.4%
110
What percentage of earths volume is Crust?
1%
111
Continental drift theory proposed by
Alfred Wegener
112
Continental drift theory proposed in year
1912
113
Evidence of sea floor spreading
- Earthquake epicentres
- Heat flow
- Ocean Sediments
- Radiometric dating of rocks of oceans and continental crust
- magnetism
114
Evidence of Continental drift
- Seismographs: revealed a pattern of volcanoes and earthquakes
- Radiometric dating of rocks revealed a surprisingly young oceanic crust
- Echo sounders revealed the shape of the Mid Atlantic Ridge
115
What are spreading centres?
where new sea floor and oceanic lithosphere form
116
What are subduction zones?
Where old oceanic lithosphere descends
117
Plates are?
- Lithosphere broken into plates
| - Rigid slabs of Rocks
118
Plate tectonics?
A unified model with ideas from continental drift and sea floor spreading
119
Seven major plates
Pacific, African, Eurasian, North American, Antarctic, South American, Australian.
120
Minor plates
Nazca, Indian, Arabian, Philippines
121
Plate boundaries in action? hint: types
1. plates move apart (convergent boundaries)
2. plates move towards each other (divergent boundaries)
3. plates move past each other (Transform boundaries)
122
Example of divergent oceanic crust
The Mid Atlantic Range
123
Example of divergent continental crust
The rift valley of east Africa
124
How many possible combinations of a convergent boundary?
3
125
Name combinations of convergent boundaries
- Ocean- ocean
- Continent- ocean
- continent- continent
126
Example of a transform boundary
San Andreas fault
127
Sea floor spreading theory was proposed in
1960
128
Oceanic crust towards Ocean crust occurring in:
Northern Pacific
129
Oceanic crust toward continental crust example
West coast of south america
130
Continental crust toward continental crust example
Himalayas
131
Magnetites occur naturally in?
Basaltic magma
132
Magnetites act as?
compass needles
133
Continental crust thickness
35-70 km
134
Oceanic Crust thickness
6-10 km
135
Age of continental crust rocks
1500 million years old
136
Oceanic crust rocks age
200 million years
137
Carboniferous period dates back how many years ago
250 million years
138
Pangaea means
Entire Mother Earth
139
The 'fit of the continents'
Francis Bacon - 1620
140
Research on rock magnetism
1960s
141
Convection current phenomenon
Henry Hess
