Exam Revision Flashcards
(129 cards)
1
Q
What is Fermi’s paradox?
A
The high probability that extra terrestrial life exists and the lack of contact humans have had with such life.
Why haven’t other planets with much older solar systems in ours developed life, and life that is intelligent enough to travel throughout space
2
Q
Oceanic crust is denser/lighter than continental crust
A
Denser
3
Q
The lithosphere is:
A
The mantle and the crust
4
Q
Asthenosphere:
A
Upper mantle
5
Q
Mesosphere:
A
Lower mantle
6
Q
Hydrosphere
A
Water layer and the hydrologic cycle
7
Q
As a result of lots of pressure, the mantle is:
A
Almost solid
8
Q
Where did water on earth come from?
A
Most of it came from the mantle, but some did come from icy asteroids
9
Q
Describe the earths magnetic field and outline the advantages of it
A
It is dipole: convection with the outer core and super rotation of inner core
Protected from the solar wind, including coronal mass ejections
10
Q
List some life support mechanisms of the earth:
A
Gravity: keeps gases and water close to surface
Magnetosphere: solar wind protection
Plate tectonics: renews surface water, gases and minerals
Orbit: the Goldilocks zone
11
Q
Exogenous hazards may include:
A
Comets asteroids solar flares
12
Q
Endogenous hazards may include:
A
Divided into the topographic layers: Lithosphere- earthquakes volcanoes Atmosphere storms bushfires Hydrosphere floods Biosphere disease and animal attacks
13
Q
The severity of a disaster on a population depends upon:
A
Quality of living Vulnerability: the ability to mitigate and adapt to changes Infrastructure Economy Government Culture Society
14
Q
Vulnerability due to climate change:
A
The susceptibility and inability to cope with the adverse impacts of climate change
15
Q
Describe the susceptibility of the worlds population to hazards
A
Most mega cities lie near coastlines, fault lines, volcanoes and are within +/- 20 degrees of equator so they’re in the tropical cyclone belt
16
Q
Disaster protection plan:
A
Recognise the hazard Assess the assets ie people, infrastructure exposed to the hazards and their vulnerability Assess the loss Manage the problem: risk mitigation Adapt to the hazard
17
Q
Effects of climate change
A
Higher average temperature, higher night minimums, temp spikes, uncertain precipitation, more extreme weather events, sea level rise, salt water inundation of coastal areas
18
Q
Effects of climate change on agriculture
A
Decrease crop yield.
19
Q
What are the ways we could adapt to changes in climate for agriculture
A
New crop varieties, diversifying farming practices, investment in technology, education and insurance systems
20
Q
Who are the possible people/ organisations that will implement changes in the way that food is produced?
A
NGOs, corporations, local/non local drivers.
Many social/political factors come into play
21
Q
Social/political effects on threats to global food security
A
Net reduction in food, greater food prices.
Many people can’t grow their food, will be impacted the most
22
Q
How is the war in Syria an example of how food security threatens national and international relations
A
Massive drought for a few years. Large scale migration to the cities. Over population, poverty, social conflict, political conflict
23
Q
Minerals are
Give an example
A
Chemically homogenous. Exist as crystal lattices, usually inorganic
Diamond, graphite, quartz
24
Q
Igneous rocks can be both
A
Intrusive (plutonic) large grain. Formed beneath the earths surface
Extrusive (volcanic) small grain. Formed in volcanoes
25
List the two types of metamorphic rocks
Contact: physically touching the heat source like magma. Allows minerals to recrystallise in the solid state. NO MELTING
Regional: formed through pressure
26
Sedimentary rocks are formed by:
| An example of a Sedimentary rock is
Erosion
| Sandstone
27
List the seven principles of geology
```
Uniformitarianism
Superposition
Original horizontally
Lateral continuity
Cross cutting relationships
Inclusion
Faunal succession
```
28
Uniformitarianism is
The present is the key to the past. Geological processes have barely changed over time. Can do relative dating
29
Superposition is
Sedimentary rocks are deposited sequentially. Youngest at the top
30
Original horizontality
Layers of sediment are deposited horizontally by gravity
31
Lateral continuity
Rocks that are similar but have been separated or eroded are assumed to be the same
32
Cross cutting relationships
Rocks being cut are older
33
Principle of inclusion is
Inclusions are older
34
Faunal succession principle is
Strata can be dated by the fossils they contain
| Eg a dinosaur bone won't be found in the same strata as a Neanderthal bone
35
Describe some absolute dating processes
Carbon dating
Tree rings tell you about climate and seasons
Lead isotope dating: told us age of the earth
Zircons are tough minerals, oldest preserved rocks
36
What is the age of the earth
4.55 Ga
37
A divergent plate boundary is
A mid ocean ridge
| A continental rift
38
A convergent plate boundary is
A subduction zone
39
A conservative plate boundary is
A horizontal plate displacement
| Lateral movement
40
```
Plate tectonics explains:
the motion of the ...
... Of the lithosphere
... Formation and dispersal
... Isolation which supports ...
Oceanic ... And changes in ...
Bi modal ...
```
```
Continents
Recycling
Geographic, evolution
Circulation. Climate
Hypsometry (measurement of land elevation relative to sea level)
```
41
Why does the earth's core remain hot?
Remnant kinetic energy from accretion (when meteors crashed together to form earth)
42
Define isostatic equilibrium
When objects of different densities force each other into equilibrium.
For instance: glaciers press into the earth. When they disappear, the lithosphere depresses
43
How do glaciers form
Continents drift over the poles
Snow remains in the same area year round
More and more snow accumulates
Pressure builds, snow compresses into small sugar like crystals
44
Milankovic orbital cycles are
Mid term climatic changes that result from the non uniform of the earth about the sun. Climates last for roughly 23 000 years.
Also called astronomical cycles
45
A decrease in sea level rise may be due to
The formation of glaciers on land
46
If glaciers form in the ocean, what change is there to sea level elevation?
No change
47
What are the impacts of glaciers that form on land?
Unique migrations across land bridges as a result of lower sea level
48
What were the implications of the break up of Antarctica from Australia?
Tethyan oceanic gateway disappeared, warm ocean currents that kept Antarctica warm disappeared. Brought PNG and Australia close to Asia
49
What is El Niño?
Brings hot dry temperatures in Australasia and unseasonal heavy rain in South America
50
What is La Niña?
Cooling of the waters in the pacific. Brings cooler wetter climate to Australia
51
What is Wallace's line
A line that separates the flora and fauna of Australia and PNG from Asia
52
Describe the Cambrian
Predation meant the development of exoskeletons eg Trilobites, horseshoe crabs. First land visits by sea scorpions
53
Define rheology
Involves the strength of a material. The ductility and brittleness
54
The focal point of an earth quake is the
Hypo centre
55
The distance from the surface crust to the hypo centre is the
Focal depth
56
The epicentre of an earthquake
The point on the surface crust directly above the hypocentre
57
Dynamic or long wave topography does what?
Examines the mantle processes beneath the crust. Measures over several hundred kilometres
58
Short wavelength topography does what?
Measures distances of only a few kilometres
59
Modelling used to be what?
Analogue using clay and sand models
60
Describe a compressional continental fault
Continents are compressed together resulting in brittle failure, or syncline and anticline patterns. Also called reverse faulting
61
A fault line that has only lateral displacement is called a
| Give an example
Strike slip
| San Andreas fault
62
What is an extensional continental fault?
Mantle convection pulls continental crust apart, also called normal faulting. Leads to thinner crust, formation of basins
63
Name the three types of oceanic faults
Extension
Strike slip
Convergent
64
Describe a convergent plate boundary and name an implication of this
Also called a subduction zone. Oceanic crust subducts beneath the lighter continental crust
Mantle plumes cause volcanoes
65
Are oceanic strike slips a tsunami hazard?
No, only lateral movement
66
Another name for an abandoned or inactive fault line is ...
| And why is it inactive?
Fracture zone
| Both plates now move in the same direction
67
Why does the age/depth relationship fall apart near continents?
Sediments and erosion
68
Medium term topography and climate is forced by
Orbital cycles, and atmosphere and hydrosphere feedback mechanisms
69
Long term topography and climate is forced by
Tectonics and mantle convection
70
Describe the Hadean period
Molten crust, moon was much closer, few rocks like zircon are preserved
71
Describe the Archean period
Onset of first continents
| Vigorous convection due to greater heat flow. More radioactivity that has decayed now.
72
Which period in time had the earliest forms of life? Describe this life
Archean. Prokaryote bacteria and stromatolites
73
When did the ozone layer develop?
Proterozoic, however very thin, little UV protection
74
What is an extremophile?
An organism living in harsh conditions ie high temperatures, toxic atmospheres.
75
What is the fundamental requirement for life?
Self replicating DNA
76
Describe the Proterozoic period
Oxygen in the atmosphere. Cyanobacteria able to photosynthesis. Evidence for single sided plate tectonics
77
The Proterozoic super continent is called. What was it
Rodinia. Land of Rodinia was entirely barren with no vegetation
78
Describe the runaway albedo effect in regard to the Proterozoic snowball earth
Ice age. Increases the amount of radiation reflected from the earth's surface, makes things colder, ice age runs away.
79
What makes glacial rocks different?
Glacial drop stones. Glaciers grind up rock and pick pieces of it up and drop it in new places
80
Describe the late Proterozoic
Ediacaran fauna, multicellular organisms with tissues and wide variety of symmetries
81
Describe the Paleozoic
Complex life, hard shells, fish, arthropods, reptiles evolved. Ended with large mass extinction
82
Describe the Cambrian
Predation meant the development of exoskeletons eg Trilobites, horseshoe crabs. First land visits by sea scorpions
83
Describe the Ordovician
Further explosion of life, burrowing animals more common
84
List the geological time scale in order
Hadean, Archean, Proterozoic, Paleozoic, Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian
85
Carboniferous
Trees and high oxygen continent, big insects
86
Devonian
Colonisation of land by trees
87
Cenozoic
c no dinosaurs, rise of mammals
88
What is cleavage in regard to minerals
Planes of weakness in the crystal lattice
89
Do all minerals exhibit cleavage?
No, but they fracture. Most common way is conchoidal
90
What is the hardness scale?
Is measured by whether a mineral or rock can scratch another surface
91
How did minerals contribute to the water that exists on earth today?
Minerals such as Ringwoodite contain water. When they are melted in the mantle, the water is released into the atmosphere
92
Rocks are composed of ...?
Minerals
93
How are intrusive rocks formed?
The slow cooling of magma underground forms large crystals
94
How are extrusive rocks formed? How does silica content relate to their viscosity?
In volcanoes.
| High silica content, the higher the viscosity
95
Name the various types of sedimentary rocks
Fluvial (river)
| Marine (made up of organisms as well as minerals) eg carbonate from shells makes chalk
96
Describe the lithification of sedimentary rocks
Deposition, compaction, cementation.
97
What is the cementation of sedimentary rocks
Dissolved material is redeposited in areas of low pressure resulting in cementation
98
How is porosity in sedimentary rocks important?
Allows movement of water through bed rock
99
Give an example of a carbonate rock and how it is formed
Limestone. Formed by the deposition of carbonate from organisms that has undergone heat and pressure
100
List the two types of carbonates that can form
Biogenic (deposition of organisms)
| Chemical (accumulation of sediment around a nucleus of sand or other grain)
101
What is an evaporite?
A chemically precipitated rock. Eg salt
102
What is regolith?
Soil. Rocks that have undergone weathering and can hold water
103
What is a fossil?
| What are the two types?
The remains or impression of once living plant or animal material
104
Is hard or soft tissue better preserved in fossils?
Hard
105
Comment on the 'colour' of dinosaurs
Fossils don't indicate colour. Scientists look at present day melanosomes for colour
106
Describe paleogeography
Study of geographical features at periods in the geological past. Tells us about the habitat distributions and climate sensitive organisms
107
Spatial coverage of fossils
Gaps in the fossil record are due to uplift and erosion (tectonism) or non depostion.
Cratonic regions that are exposed do not contain fossils
108
Describe trace fossils
They preserve the behaviour of animals, like burrows and tracks, often indicate the position of rocks (up or down)
Depth is also indicated by the areas at which organisms lived.
109
Event Stratigraphy can be used to ...
determine the age of rocks and thus define the period of time they were from
110
Isotope stratigraphy is what?
Dating of strata based on the content of various isotopes of oxygen for instance. Concentration of oxygen 18 decreases with temperature. It is also denser and is found more commonly in oceans. Indicates time periods
111
What is sequence stratigraphy?
changes in sea level: transgression and regression (rise and fall). Predictable shifts in sedimentation
112
Define Paleoclimate
A climate that was prevalent at a particular time in the earth's history
113
The atmosphere is an ocean of air. Elaborate pls
There is pressure because of weight, eddy currents form clouds around mountains.
114
Nitrogen is ... by biological processes, stopping it from ...
Fixed, increasing infinitely
115
Homosphere is ...
turbulent so everything is mixed up. As you cross the turbopause, less turbulence, enter the heterosphere, layers of gases separated by atomic weight
116
Name the layers of the atmosphere
```
Trevor: Troposphere
Started: Stratosphere
Making: Mesosphere
The: Thermosphere
Eggplant: Exosphere
```
117
How do we value the environment?
It does work for us so we value it. For instance soil formation, medicinal resources, gas regulation
118
The atmosphere is fluid as a result of ...
Earth's systems trying to redistribute heat
119
What is a Hadley cell? What are the implications?
Atmospheric currents that rise at the equator and fall at about +/- 30 degrees. Increases precipitation. Cool dry air falls. Locations at around 30 degrees north and south of the equator are commonly deserts
120
What is the Intertropical Convergence Zone
A zone near the equator where north and south air masses converge, creating a low pressure zone
121
Why is the equator hotter?
It is perpendicular to the sun in the earth's orbit and is less able to reflect heat like the poles
122
What is the coriolis effect
an effect whereby a mass moving in a rotating system experiences a force (the Coriolis force ) acting perpendicular to the direction of motion and to the axis of rotation. On the earth, the effect tends to deflect moving objects to the right in the northern hemisphere and to the left in the southern and is important in the formation of cyclonic weather systems.
123
Describe the difference between homonin and homonid
nin is exctinct, id is modern human
124
What led to bipedalism in early humans?
Increased aridity in Africa due to growing rift valley and the India eurasia collision thinned out forests, was better to stand up and walk the longer distances
125
Describe an Australopithicus
Earliest bipedal homonids, smaller brain, now extinct
126
Homo Habilis was ...
Larger brain than australopithicus, use of tools, still small
127
Homo erectus
Upright man, use of fire
128
Homo neanderthalensis
Only existed in Eurasia, heavy build, complex society, had a language probably
129
Homo Sapiens
Modern humans, highest cranial capacity, dominant species on planet, only surviving species of homonin
