earth sciences Flashcards
(125 cards)
1
Q
What are earths three layers
A
the crust, the mantle, the core
2
Q
Which layer is the hard outer layer of the earth
A
The crust
3
Q
Which layer is the thinnest layer
A
The crust
4
Q
Under the oceans what layer is only about 5 km deep
A
The crust
5
Q
Under most of the land what layer is about 30 km deep
A
The crust
6
Q
Under mountains what layer is about 100 km deep
A
The crust
7
Q
What is under the crust
A
The mantle
8
Q
Which layer is very thick and is about 2900 km thick
A
The mantle
9
Q
Describe the outer part of the mantle
A
It is cooler and more solid than the inner part
10
Q
What forms the lithosphere
A
The cooler outer part of the mantle and the crust together
11
Q
Where is the Mohorovicic discontinuity
A
Where the upper part of the mantle ends and the liquid part begins
12
Q
The mantle is also called
A
The mesosphere
13
Q
What is the mantle made up of
A
Liquid rock
14
Q
What is the layer just below the lithosphere And is made of liquid rock that is more like liquid plastic
A
The asthenosphere
15
Q
What is the core also called
A
Centrosphere
16
Q
What layer is the very inner part of the earth
A
The core
17
Q
Core has two parts what are they
A
The outer core and the inner core
18
Q
What is the outer core And how thick is it
A
It’s liquid and about 2200 km thick
19
Q
Is the inner core and how thick is it
A
It is solid and is about 1250 km thick
20
Q
What creates earths magnetic field
A
The liquid outer core spins against the inner core
21
Q
What is sial
A
It is the lighter materials and is composed of mostly silicon and aluminum
22
Q
What is sima
A
It is the dancer material that is composed largely of silicon and magnesium
23
Q
What does sial form
A
The continents and landmasses
24
Q
What does sima form
A
It forms the ocean bottoms
25
Is the most common rock in sial
Granite
26
Most common rock in sima
Basalt
27
What is Isostasy
The balance or equilibrium achieved when one thing is in balance with another
28
Is the theory of Isostasy
The earth is surrounded by a layer of sima In a continuous shell. On the slayer blocks of sial Float. New land is always being made and all the land is always being worn away this means that the weight of the sial Is always changing, so balance cannot be found
29
What is the continental drift theory
300 years ago all the continents were attached informed one large continent called Pangea
30
Who suggested the continental drift theory
Alfred Wegner
31
Is some evidence of continental drift
What’s the line fit, geological fit, paleoclimatology, Paleo glaciation, fossil correlation, palaeomagnetism
32
why didn't other scientists believe Wagner
Is evidence was only circumstantial, he could not explain how the continents moved.
33
What is subduction
IThe process that occurs when two tectonic plates come together. One plate goes up, and the other goes down. The plate that goes down is said to be subducting, and the part of the cross that is going down goes to the mantle, where it melts and becomes magma
34
What are the three basic types of rock
Igneous/ fire rock, Sedimentary/layers of dust, Metamorphic/rock that changes physically or chemically
35
What are the main processes that change rock
Erosion heat and pressure
36
What happens to magma when it crystallizes
Becomes igneous rock
37
What happens if the igneous rock is subducted and is moved back into the mantle
Melts and becomes a magma again
38
What happens if igneous rock experiences heat and pressure
It may change its form completely and become metamorphic rock
39
What happens if igneous rock is eroded
The particles break away and become sediments
40
What happens when sediments from eroded igneous rock experience great pressure
They harden into sedimentary rock
41
What happens when new sedimentary rock erodes
It becomes sediments again
42
Happens when sedimentary rock experiences heat and pressure
It changes into a metamorphic rock
43
Happens when sedimentary rock gets subducted
Melts into the mantle as magma
44
What happens to metamorphic rock when heat and pressure happens
The rock changes chemically or physically into a new type of rock
45
What happens when metamorphic rock Erodes
It becomes sediments again
46
Happens when metamorphic rocks get subducted
It melts into the mantle as magma
47
What Happens when plates move apart
Initially, causes rifts, later, plate formation (fault mountains, volcanoes)
48
What happens when plates move together
Plate Destruction-subduction (fold mountains, fault mountains, volcanoes)
49
What Happens when plates experience lateral movement
Causes violent movement also known as earthquakes
50
What is plate subduction
Two plates come together, the heavier plate slides under the lighter one, and the higher one slides up and over the heavier one
51
What happens when two plates make contact
Fold mountain is created
52
What happens when plates move away from each other and space is left between them
Becomes a valley or fills with water and becomes a Sea
53
Does an earthquake happen
One Plate will try to slide past another plate, friction will hold the plates in place, but pressure will build up. When the pressure to move is too much, the plates one move suddenly and quickly against each other
54
How Is a volcano made
Are you a small opening is made in the crust, the molten lava and other material build up a cone
55
The funnel shaped opening called
Crater
56
What are the three basic types of volcanos
Cinder cones, dome cones, composite cones
57
What Kind of volcanos are very explosive and cause a lot of destruction
Cinder cones
58
What Volcano has steep sides and a narrow base and grows very quickly
Cinder cones
59
Why are cinder cones not taller
Their eruptions are often so violent that they blow the whole top part of the mountain apart
60
What volcano is not explosive but rather thick magma oozes out and generally moves slowly
Dome volcano
61
What does a dome volcano look like
Wide base but low, gently sloping sides
62
What kind of volcano Steep sides when it erupts violently and a wide base when it erupts gently
Composite cone
63
What Are destructive affects of volcanos
- explosions, lava flows
- Tsunamis
- nuees Ardents (large dark clouds of hot steam and poison gas)
- earthquakes
- mudslides (mixture of ash and water)
64
What are benefits of volcanos
- Soils from mineral rich volcanic rock are great for farming after erosion has occurred
- Builds new land
65
What is a dike
Magma cools in a vertical crack
66
What is a sill
Magma flows between strata of sedimentary rock forms a thin but extensive sheet
67
What is a laccolith
A sill that is large enough to raise a dome shape on the surface of the earth
68
What is a batholith
Mass of magma that has intruded into a wide area and has no depth
69
What happens when the plates are put under stress
A fracture often occurs in the rocks
70
What is the line of fracture called
A fault
71
Does this fault look like
And on one side of the fall will go up and the other side will go down
72
What is the Cliffs called that the fault mountains create
Escarpment
73
What Is compression
When the plate is being pushed together
74
What is tension
When the plate is being stretched
75
What is shearing
When two plates slide past each other
76
When two plates push together, the lighter plate will slide upward and the heavier plate will slide down, what is this movement called
Reverse or thrust fault
77
What causes landslides
The cliff (the hanging wall) is heavier on the top, it will collapse, causing landslides
78
When two plates pull away from each other, one side will slide downward, what is this called
A normal fault
79
If the movement along the fault line is horizontal, no changes in elevation usually occur, what type of fault is this called?
Strike-slip fault
80
When tectonic plates are compressed, instead of breaking what else could happen
They can bend and warp
81
Can folding and faulting occur at the same time?
Yes
82
What is the upward part of the fold called?
Anticline
83
What is the downward part of the fold called
Sincline
84
Sometimes the fold becomes so big that it flops over, what is this called
Overturned anticline
85
What is weathering
The process by which rock breaks down into smaller pieces
86
What are the two types of weathering
Mechanical and chemical
87
What is mechanical weathering
The breakup of rock into increasingly smaller pieces, with no change to the chemical structure of the rock
88
What is chemical weathering
The disintegration or dissolution of rock. The chemical structure of the rock is changed
89
What is erosion
The process by which rock disintegrates, dissolves, or are broken down and the particles are carried away
90
What are three methods of erosion
Wind, water, glaciers
91
What are the four main causes of mechanical weathering
Temperature changes
Frost action
Root action
Animal and insect activity
92
How does temperature change weathering work?
During the heat of the day the rocks expand, but at night they contract. This process happens over and over again causing a huge stain on the rock. The strain will crack and break the rock
93
What speeds up temperature change weathering
The greater the temperature variation
94
How does frost action weathering work
Water get into crack and freeze, the freezing water expands and pushes against the sides of the crack making the crack a little bit bigger every time this happens. The crack will become so large that the rock will split apart
95
How does root action weathering work
As a root grows in the cracks of a rock it forces the sides of the crack to widen. After a while the crack becomes so big that the rock spilts apart
96
How does animal and insect activity weathering work
Animals and insects burrow or dig in the ground and let’s water into the ground. The water weather the rocks either by drag action or by chemical erosion
97
_________________ can cause rocks to dissolve
Chemical interactions
98
What takes longer chemical weathering or mechanical weathering
Chemical
99
Chemical weather happens faster where
In hot climates
100
Most chemical weathering is caused by what 3 ways
Oxygen
Rain water
Carbon dioxide
101
how does oxygen weathering work?
air links up with some elements of other rocks, an oxide is formed, the oxide is brittle and causes the rock to crumble.
102
How does rain water weathering work? (1st way)
Rain water can dissolve some minerals. The minerals wash out of the rock with the water, making the rock weak and crumble
103
How does rain water weathering work? (2nd way)
Rain water links up wth minerals in the rock and forms new substances, the new substances break away from the rock and the rock crumbles
104
Rain water weathering will faster weather___ _______________
On rocks which it lands on
105
What is creep
The sand particles are too large to be picked up so it rolls on the ground
106
What percentage of soil is moved by creep
25%
107
What is saltation
The soil particles get picked up and bounce off the ground
108
What percentage of soil is moved by saltation
50%
109
What is suspension
When soil particles are kept in the air by the wind
110
What percentage of soil is moved by suspension
25%
111
What is a u-shaped valley
V-shaped called frowned by rivers will fill with glacial ice which erodes the sides leaving a U-shaped valley
112
What is a cirque
A scooped out basin at the head of an alpine glacier valley
113
What is a tarn
A small mountain lake, that forms in a cirque basin
114
What is a horn
A sharp, jagged peak that forms when several cirques surround a mountain
115
What is an arête
A sharp ridge that divides two cirque basins
116
What is a col
Is created on the second advance of the glacier
117
What is a striation
When glaciers move debris across the surface of the earth, scratches, called straitions, are left on the ground, indicating the direction of the retreat of the glacier
118
What is a spillway
As water from a melting Glasgow flows over the land, it cuts deep valleys into the earth.
119
What is a till plain
Is a flat area of land where a glacier has deposited the till
120
What is till
Rocks after materials left behind for the retreat of the glacier
121
What is a terminal moraine
Material deposited by a glacier at the farthest point the glacier reached
122
What is a lateral moraine
Debris transported by a glacier that collects along the sides of the glacier
123
What is a drumlin
- a glacial landform that is made of till and is shaped like a tear drop
- it forms in the direction of the ice movement
- scientists don’t know how these are formed
124
What is an erratic
A dropped of rock from the melting of the glacier that carried it, these rocks are dropped off anywhere and look very out of place
125
What is a lacustrine plain
Fertile bottom of an ancient glacial lake that is now used for agriculture
