GEO1YR9

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What is a natural hazard?
A natural hazard is the chance or probability
of being affected by a natural event.
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What are the layers of the earth?
Crust
Mantle
Outer core
Inner core
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What are convection currents?
Process underneath the earths surface force rock in the mantle to rise upwards cool and then sink down again. Convection currents in the earth cause the rock in the mantle to move in a circular motion from outer core to the crust, and back again. This cau
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What is the crust?
It is the layer we live on
8-65km thick
The exact thickness of the crust varies-it is thinner where there are oceans and thicker where there are mountains
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What is the Mantle?
The largest layer. The top part is hard but the lower part is runny. 2900km thick.
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What is the Outer Core?
This layer is liquid and made of iron and nickel. 2220km thick.
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What is the inner Core?
This is the hottest layer. It is solid. The temperature here is around 5500 °C. 12600km thick.
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What is continental crust?
The thick crust
which has land on it.
25 – 70 km thick. It is
less dense.
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What is oceanic crust?
The thin crust
under the oceans. It
is thin but dense
(heavy).
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What is magma?
Hot molten rock
from the mantle that
reaches the surface.
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What is a plate boundary?
Where the edge of 2 plates meet
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What happens at a Constructive Plate Boundary?
Causes earthquakes
Move away from each other, magma rises to fill the gap
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What happens at a Destructive Plate Boundary?
Causes earthquakes
Move towards each other the oceanic plate subducts under the continental plate. They pressure builds up then erupts. The friction causes an earthquake.
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What is a Collision Plate Boundary?
Causes earthquakes
Move towards each other creating fold mountains.
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What is a Conservative Plate Boundary?
Causes earthquakes
Side by side, in opposite directions or the same direction.
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What are hot spots?
Causes earthquakes and volcanoes
Weak points on a plate magma escapes.
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What are the cross sections of a volcano?
Volcanic bombs,ash,lava,gases
Magma chamber
Crater
Secondary cones
Main vent
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Volcanic bombs, ash, lava, gases.
Volcanic bombs are lumps of molten rock that solidify as they fall. Ash is made up small pieces of shattered rock thrown from the volcano.
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What is a magma chamber?
A store of molten rock deep inside the earth
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What are secondary cones?
Form in the main vent is blocked and the magma is forced to the surface by another route.
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What is an active volcano?
If it has erupted recently it is likely to do so again.
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What is a dormant volcano?
A volcano which hasn't erupted for many yesrs.
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What is an extinct volcano?
A volcano which has not erupted for many thousands or millions of years.
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What are shield volcanoes?
Shield volcanoes are usually found at constructive plate boundaries. They are low in height, with gently sloping sides. They are formed by eruptions of thin, runny lava. Eruptions tend to be frequent (sometimes continuous) but relatively gentle (not viole
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What are composite volcanoes?
Made of alternating layers of
lava and ash. Lava is viscous and does not flow easily, creating steep sides Mainly found at destructive plate boundaries Rocks harden quickly blocking the vents, which builds pressure and leads to violent eruptions The erupt
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What are advantages of living with volcanoes?
Farming opportunities
Mining opportunities
Geothermal Energy
Tourism
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What is a supervolcanoe?
An eruption that emits at least 1000km cubed of material
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Formation of supervolcanoes
Rising magma cannot escape and a large bulge appears on the surface
Cracks appear in the surface and gas and ash erupt from the magma chamber
The magma chamber collapses forming a depression called a caldera.
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Why was the asian tsunami 2004 so deadly?
9.1 magnitude
many poor countries
Huge death toll
No warning-So people weren't prepared
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What are tsunamis?
Tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea.
Destructive plate boundaries
Ocean floor can violently move upwards which then forces the water to create huge vertical waves. The wave becomes visible as it reaches land,
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What is a glacier?
A glacier is a slowly moving mass of ice.
Longer answer-glaciers are large bodies of ice that cover about 10% of the Earth’s surface in cold regions such as Antarctica and the Arctic as well as in high mountain ranges such as The Alps, Andes and Himalayas
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When did the last ice age start and finish?
It began about 110,000 years
ago and ended 10, 000 years ago
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Why has the ice come and gone?
Milankovich - Earth's elliptical orbit, tilt changes, sun spot variations, and volcanic activity contribute to variations in heat received from the sun and ash reduction in heat.
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What are the natural causes of climate change?
Volcanic Eruptions
Sunspots
Orbital Changes
Asteroid Collisions
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What is glacial erosion?
A glacier will erode if it has a continuous supply of material with which to erode. Freeze thaw weathering and erosion by plucking and abrasion are the most significant processes that lead to the
formation of a distinct glacial landscape.
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How does Freeze-thaw weather the
rocks?
Water enters cracks in the rock. When temperatures drop, the water freezes and expands causing the crack to widen. The ice melts and water makes its way deeper into the cracks. The process repeats itself until the rock splits entirely.
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What are glacial landforms?
Pyramidal peak
corrie
Hanging valley
Arêtes
U- Shaped valley
Ribbon lake
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What is a pyramidal peak?
Pyramid –shaped mountain peak formed as three or
more corries cut back towards each other
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What is a corrie?
Rounded hollow in the mountainside where a glacier is formed.
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What is a hanging valley?
V-Shaped valley above the level of the ice
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What is a aretes?
Steep, narrow, knife-edged ridge separating two
corries
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What is a Ribbon lake?
Long narrow lake occupying a glacial valley; they
often form behind glacial deposits at the end of the valley
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What is a U-Shaped valley?
Former V-Shaped river valley whose sides have been steepened (spurs truncated) and the floor deepened by the weight of the glacier and its erosional powers
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What are erratics?
These are large boulders dumped by the
melting ice. They may appear to be out of
place because they have been transported
from a different area.
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What are drumlins?
These are mounds of glacial material, deposited by the glacier. The exact process of formation is not known. They lie parallel to the direction of the ice movement. They have a smooth elongated shape because of later ice movement over them.
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What is Moraine?
A moraine is material left behind by a moving glacier.
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What is Ground moraine?
Material that was at the bottom of the glacier. It is found on the valley floor when ice melts. This is also called till.
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What is Terminal moraine?
Material that is left piled up at the snout of the glacier.
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What is Lateral moraine?
Occurs at the sides of the glacier. It is made of rocks that have been weathered from the valley sides by freeze-thaw.
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What are some human activities in glacial landforms?
Skiing,Snowboarding,Climbing,Cycling,Parachute,Rafting,Mining,Glacier Hiking,Sledging,Farming
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What is the coast?
The coast is the boundary between the land and the sea. At the coast waves affect the shape of the land constantly changing it by many different processes. To understand the coast we must understand how waves operate.
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What are waves caused by?
Waves are caused by the transfer of energy from the wind to the sea due to friction of the wind on the waters surface.
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What is the size and energy of a wave influenced by?
How long the wind has been blowing
The strength of the wind
How far the wind has travelled (the fetch)
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What is a swash?
When water moves up the beach
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What is a backwash?
When water moves down (away from) the beach
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What is coastal erosion
Coastal Erosion is the wearing away of the land by
the sea.
Different types of rocks wear away at different speeds and in different ways.
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How does Hydraulic Action erode?
This is the force of the water hitting the cliff and
squeezing air into the cracks in the rock
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How does Abrasion erode?
The waves fling sand and pebbles against the
rock. These wear it away like sandpaper. This is
called abrasion
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How does Attrition erode?
This is the process of rocks hitting each other
and breaking into smaller rocks. They end up as
shingle and sand
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How does Solution erode?
The waves dissolve soluble material from the
rock e.g. limestone
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What is wave-refraction?
The waves bend to the shape of the bay
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How does a cave form?
The sea attacks cracks in the cliff
at a headland through erosional processes such as hydraulic action and abrasion. The cracks grow larger, and form a cave.
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How does an arch form?
Eventually ,the cave gets eroded all the way through until it turns into an arch.
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How is a stump formed?
Althpugh the waves cant reach the top of the arch sub-aerial processes act from above causing it to collapse leaving an isolated stack. In time, the waves erode the stack through hydrualic action
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What is longshore drift?
This movement of sediment along the coastline.
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What are types of coastal transportation?
Solution
Suspension
Traction
Saltation
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What is Solution transportation?
Dissolved chemicals often derived from limestone or chalk.
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What is Suspension transportation?
Particles carried (suspended) within the water
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What is Traction transportation?
Large pebbles rolled along the seabed
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What is Saltation transportation?
A 'hopping' or 'bouncing' motion of particles too heavy to be suspended
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What are types of coastal protection?
Groynes, Rock Armour, Beach replenishment, Dune regeneration, Gabions, Sea wall
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What is hard engineering?
Strategies that stop coastal processes e.g. groynes
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What is soft engineering?
Strategies that work with the coastal processes e.g. beach replenishment
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Other cards in this set

Card 2

Front

What are the layers of the earth?

Back

Crust
Mantle
Outer core
Inner core

Card 3

Front

What are convection currents?

Back

Preview of the front of card 3

Card 4

Front

What is the crust?

Back

Preview of the front of card 4

Card 5

Front

What is the Mantle?

Back

Preview of the front of card 5
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