Paper 1 Flashcards
(135 cards)
1
Q
What is a natural hazard? (G)
A
A natural event or process which causes loss of life and or damage to property which creates disruption to human activities.
2
Q
What are some examples of natural hazards? (G)
A
- Hurricane
- Hail
- Earthquake
- volcanic activity
- landslides
3
Q
What are the types of natural hazards? (G)
A
- Geological Hazards
- Biological Hazards
- Meteorological Hazards
- Geomorphological Hazards
4
Q
What is a geological Hazard and some examples? (G)
A
Movement of the earth
- earthquake
- landslides
- tsunamis
- volcanic activity
5
Q
What are biological hazards and some examples? (G)
A
Disease epidemics and insect / animal plagues
- Ebola
- COVID
6
Q
What are meteorological /atmospheric hazards and some examples? (G)
A
Caused by the atmosphere (weather + climate)
- tropical storms
- drought
- wildfires
- extreme temperatures
7
Q
What are geomorphological hazards and some examples? (G)
A
To do with water on the land
- avalanches
- floods
8
Q
What is a hazard risk? (G)
A
The probability of being affected by a natural event
9
Q
What are the factors affecting hazard risk? (G)
A
- Vulnerability (costal - tropical storms, urban - earthquakes, Lic - less preparation for natural hazards)
- Capacity to Cope ( HIC better leopardess coz monitor, predict and evaluate)
- Nature of Natural Hazards (higher storm on saffir Simpson scale or higher an earthquake on the Richter scale - the worse it is) (if it has natural hazards)
10
Q
Describe the earth’s crust (G)
A
The crust lays above the mantle and is the earths outer shell. The crust is thinner than the other layers (4-7 miles deep). It is a solid
11
Q
Describe the earths mantle (G)
A
The layer above the outer core. 1800 miles thick and makes up 80% of earths total volume. Made of molten rock.
12
Q
Describe the earths outer core (G)
A
So hot that the metal is always molten with temperature reaching 3700C. 1370 miles thick. It is a liquid
13
Q
Describe the inner core (G)
A
Centre of the earth is solid (iron, nickel) and about 750 miles thick.
14
Q
Describe a continental crust (G)
A
- thick
- light
- land on top
- goes up when it meats oceanic
- North American Plate
- when this meets another continental, the denser one goes down (Mariana Trench)
15
Q
Describe an oceanic crust (G)
A
- Thin
- heavy
- dense
- ocean / sea on top of it
- goes down when continental meets it
- Pacific plate
- when these two meet they go up to form mountains .
16
Q
What are the two plate tectonic theories? (G)
A
- convection
- ridge push / slab pull
17
Q
Describe the tectonic theory of convection currents. (G)
A
The crust of the earth moves because of the convection currents in the Mantle. The moltern rock is heated up by the core and as heat rises, it moves upwards towards the crust. As it does this it loses heat, cools and sinks again. This moves the plates. If convection currents move apart from each other, it splits the crust. If convection currents move together, the crusts collide.
18
Q
Describe the tectonic theory of Ridge Push, Slab Pull. (G)
A
Example: mid atlantic ridge.
Ridge Push = When plates move apart (constructive boundary) the magma rises from the mantle. It creates new, hot, dense rock. This creates a ridge at the crust
Slab Pull = Gravity pulls the old rock into the mantle because the rock has become colder and dense. This occurs at subduction zones at destructive boundaries
19
Q
Describe for 4 marks the global distribution of earthquakes and volcanic eruptions and their relationship to plate margins (G)
A
The main pattern is they are located on or near plate boundaries.
Volcanoes are found around the Pacific Ring of Fire and the Mid-Atlantic Ridge (Iceland).
Earthquakes are found between the Eurasian and African Plates.
Anomilies include the Hawaii Island chain (middle of Pacific Plate) becuase it is a hot spot.
20
Q
What is the physical process taking place at a constructive plate margin? (G)
A
- The plates move apart due to convection currents and ridge push.
- An example is the Mid-Atlantic Ridge in Iceland
- The North American and Eurasian Plates split apart (example)
- Pressure and Friction build up. When they are released an earthquake is caused.
- volcanoes form at the ridge and can create new land
21
Q
What are the hazards of constructive margins? (G)
A
Volcanoes and Earthquakes
22
Q
Describe the physical process taking place at a destructive margin. (G)
A
23
Q
What are the conditions for a tropical storm?
A
- 26.5 degree water so that it warms the air above it
- low air pressure so that it the moisture rises
- 60ft deep water so that there is enough for a storm
- Coriolis effect so that the clouds rotate
- trade winds so that it moves west
24
Q
What is the coriolis effect?
A
The spinning of the earth on its axis makes the clouds of tropical storms rotate
25
What is the sequence of tropical storm formation and development?
1. Air above tropical water is heated and rises through evaporation
2. The coriolis effect makes the winds rotate and the trade winds send it west
3. As it rises the air cools and moves outwards, leaving space for warm air to rise
4. Clouds form and start to rain
5. Trade winds cause it to travel west towards land
26
What is the eye wall of the storm?
The most violent/ fastest winds
27
What is the longest distance a tropical storm can stretch to at one time?
10000km from the eye
28
What is the highest the cloud top can be in a tropical storm?
15km
29
How long can a tropical storm last?
Up to 14 days
30
What is the weather in a tropical storm?
Strong winds
Dense cloud cover ~ spiral
Humid
Low air pressure
Lots of rain
Eye of the storm = calm because the air is sinking.
31
What is the scale that measures the strength of a tropical storm?
Saffir Simpson scale
32
What is the saffir Simpson scale?
Measure tropical storms
1- 5 5=worst
33
How does climate change affect the distribution, frequency and intensity of tropical storms?
Distribution
- sea surface temperatures in the Tropics have increased by 0.25 - 0.5 degrees.
- in the future, tropical storms may affect areas outside the current hazard zone, such as the South Atlantic and past the subtropics because sea temperatures are increasing
Frequency
- no clear evidence that the frequency of tropical storms is increasing
Intensity
- there is clear evidence that the intensity of tropical storms are increasing. This is linked to increases of sea surface temperatures, which gives the storm more power.
34
What is the example of a tropical storm?
Typhoon haiyan
35
What were the facts about typhoon haiyan?
In 2013
in the Philippines,
Catagory 5
Wind speed of 195mph
Gusts of 235mph
Waves were 15m high
36
Primary effects of typhoon haiyan?
- 6300 killed by drowning
- 600000 displaced
- 1 million homes damaged
- 30000 fishing boats destroyed so no food or income
37
Secondary effects of typhoon haiyan?
- 6 million lost their source of income
- ferries and flights disrupted for weeks which slowed aid efforts
- shortage of water, food and shelter which led to outbreaks of cholera
38
What were the immediate responses to typhoon haiyan?
- 1200 evacuation centres set up to help the homeless
- Philippines Red Cross delivered basic food aid
- field hospitals set up to help the injured
39
What were the long term responses to typhoon haiyan?
- ‘Cash for Work’ programmes where people were paid to help clear debris and rebuild the city
- more cyclone shelters built to accommodate people evacuated
- rebuilding
40
What are the three ways of reducing the effects of tropical storms?
Prediction
Planning
Protection
41
What is hurricane prediction?
The use of technology to monitor more accurately and effectively
- hurricane watch - advises that hurricane conditions are possible
- hurricane warning - advises that hurricane conditions are expected and that people should take immediate action.
42
Positives and negatives of hurricane prediction?
P - time to evacuate
N - chance that the prediction might be wrong
43
Positives and negatives of hurricane monitoring?
P - scientific predictions
N - difficult to be accurate
Haiyan wasn’t prepared
44
What is hurricane planning?
Raising individual and community awareness so that people understand the potential dangers and are able to respond
- families encouraged to devise own plan of action
- education of potential dangers
45
What are the positives and negatives of hurricane planning?
P - people are more prepared
N - prediction may not be accurate
Haiyan was in an LIC so lack of money for good building materials
46
What are the ways of hurricane protection?
- windows, doors and roofs reinforced to strengthen buildings to withstand strong winds
- sea walls built to protect key properties from storm surges
- In Bangladesh nearly 2000 cyclone shelters have been built
47
What are the positives and negatives of hurricane protection?
P - reduces cost of damages
N - costly
48
What are the weather hazards that Dan be experienced in the UK?
Flooding
Drought
Snow storms and freezing temperatures
Tornado
49
What are the details of flooding?
Heavy rain from storms (tropical maritime airmass) for example storm Dennis in 2010
50
What are the details of drought?
Heatwaves in 2022 and 2020 (tropical maritime airmass)
Hosepipe banes were enforced
51
What are the details of snow storms/ freezing temperatures?
In 2022 temperatures plummeted to -10 degrees in Scotland and the north east of England. 2018 beast from the east
52
What are the details of tornadoes
In 2006 there was an F2 tornado in London, 6 people were injured and 100 properties were damaged.
53
What were the primary effects of the Haiti 2010 earthquake?
- 220,000 people killed
- 300,000 people injured
- 200,000 homes destroyed
- shipping port was damaged
- dead bodies left in the street
- roads were blocked by buildings and cars
54
What were the secondary effects of the Haiti 2012 earthquake?
- 1.3 million Haitians were homeless
- over 2 million Haitians didn’t have food nor water
- the tourism industry declined
- water became contaminated so cholera spread
- looting occurred in shops
55
What were the immediate responses to the Haiti earthquake in 2010?
- members of social networking sites such as Twitter and Facebook spread messages and pleas for help
- 39 trucks carrying canned food were dispatched
- The Dominican Red Cross coordinated early medical relief
56
What were the long term responses to the earthquake in Haiti in 2010?
- Haiti received $1 billion in aid
- after the earthquake many residents came back to the rural towns that they came from
57
What were the two plates and the margin formed in Haiti?
North American Plate and Caribbean plate
Conservative margin
58
What were the primary effect of the haiti earthquake? (CS)
- 220,000 people were killed
- 300,000 people were injured
- 200,000 homes destroyed
- shipping port was damaged
- dead bodies were left in the streat
- roads were blocked by buildings and cars
59
When was the haiti earthquake? (CS)
2010
60
What were the secondary effects of the haiti earthquake? (CS)
- 1.3 million Haitians were displaced (homeless)
- Over 2 million haitians didn't have food and water
- the tourism industry declined
- water became contaminated so cholera spread
- looting occured in shops
61
What is the margin of the haiti earthquake? (CS)
conservative margin
62
what are the two plates meeting near haiti? (CS)
north american plate
caribbean plate
63
What were the immediate resonses of the haiti earthquake? (CS)
- members of social networking sites such as Twitter and Facebook spread messages and pleas to send
- 39 trucks carrying canned food were dispatched.
- The dominican red cross coordinated early medical relief in conjunction with the red cross.
64
What were the long term responses of the haiti earthquake? (CS)
- haiti recieved $1 billion in aid
- After the earthquake, thousands of Port-au-Prince residents began returing to the rural towns they came from
65
When was the Christchurch earthquake? (CS)
2013
66
What were the primary effects of the christchurch earthquake? (CS)
- 181 people were killed, 80 of whom were killed when the CTV building collapsed
- 200 people were injured
- 50% of the central city's buildings were severly damaged
- 80% of the city was without power
- cars fell into sink holes
67
What were the secondary effects of christchurch? (CS)
- flooding from liquefaction
- business were put out of action = less income
- Christchurch could no longer host Rugby World Cup matches so lost the benefits e.g tourism income they would bring
68
What were the short term responses to the christ church earthquake? (CS)
- ordinary people helped to rescue those who were trapped
- urban search and rescue was there within a couple of hours of the event
- chemical toilets were provided for 30,000 ppl
69
What were the long term responses for the christchurch impact? (CS)
- provided temporary housing and ensured all damaged housing was kept water tight
- water and sewerage was restored for all residents by august.
70
When was typhoon haiyan? (CS)
november of 2013
71
What catagory was typhoon haiyan? (CS)
a catagory 5.
72
Where is the place that typhoon haiyan hit first? (CS)
the Philippines
73
What were the winds and waves like in Typhoon Haiyan? (CS)
winds - up to 170mph
waves - high as 15m
74
What were the primary effects of Typhoon Haiyan? (CS)
- about 6300 people were killed. most of them were downed by the storm surge
- over 600,000 people displaced and 40,000 homes damaged
- 90% of Tacloban city was destroyed
- 30,000 fishing boats were destroyed
75
What were the secondary effects of typhoon haiyan? (CS)
- 14 million people were affected, many left homeless and 6 million people lost their source of income
- power supplies in some areas were cut off for a month
- shortage of food, water and shelter affected many people, leading to outbreaks of disease
- looting and violence broke out in Tacloban
76
What were the immediate responses to typhoon haiyan? (CS)
- over 1200 evacuation shelters set up
- french and belgium field hospitals set up
- the philippines Red cross delivered basic food and aid.
- US helicopters assisted with the search and rescue and delivery of aid.
77
What were the long term responses of typhoon haiyan? (CS)
- Aid agencies such as Oxfam supported the replacement of fishing boats
- rebuiling of roads, bridges, and airport facilities
- 'Cash for work' programmes ~ people paid to help clear debris and rebuild the city.
78
what were the causes of the beast from the east? (CS)
- heavy snowfall between 27th and 29th February 2018
- The jet stream shofted south
- a polar vortext of cold air from siberia blew acroos Europe
- storm Emma was also coming up from Europe and make the Beast even worse as the two storms met
- all of the UK was affected with heavy snow
79
What were social impacts of the beast from the east? (CS)
10 people died
- thousands of shools were closed for more than one day
- hundreds of people were stranded across the UK as roads became impassable
- supermarkets across the UK ran out of food as many "panic bought" supplies
80
What were the economic impacts of beast from the east? (CS)
- local businesses lost trade
- farmers who are busy with lambing season losing their stock
- thousands of shcools were closed for more than one day
81
What were the enviromental impacts of the beast from the east? (CS)
- snow drifts in excess of 7m in places
- farmers who were busy with lambing season losing their stock
82
What were the immediate responses to beast from the east? (CS)
- curches opened their doors to the homeless
- armed force deployed to rescue stranded drivers and to transport NHS workers
- Red cross issue blankets to people stranded at Glasgow airport
83
What were the long term responses to the beast from the east? (CS)
- the government is reviewing emergency plans so we are better prepared for the future
- repairing roads and filling pot holes
84
What are some causes of deforestation in the amazon?
- Logging
- Mineral Extraction
- Commercial Farming (cattle ranching)
85
What is logging in the amazon?
It is clear felling, where all trees are chopped down in an area.
This led to the total destruction of forest habitants.
Only 2-3% of the rainforest is lost because of this.
86
What is mineral extraction in the amazon?
Mining gold and iron ore is done to make money.
Only 1-2% of deforestation is caused by this.
87
What is Commercial Farming in the Amazon?
65-70% of all deforestation is in the Amazon is caused by commercial farming
During the 1970s, large areas of land were converted to palm oil plantations.
88
What are some impacts of deforestation in the Amazon?
- Soil Erosion
- Loss of biodiversity
- Contribution to Climate Change
89
What is soil erosion from deforestation in the amazon?
the roots of trees and plants bind the soil together, so deforestation means that soil can easily become loose and erode away
90
What is the loss of biodiversity from deforestation in the Amazon?
The Amazon rainforest is home to 50% of the world's plants and animal species. If deforesetation take place then these plants, plus other undiscovered plants will be destroyed.
91
What is the contribution to climate change from deforestation in the amazon?
Trees store CO2, if these trees are cut down then CO2 is released back into the atmosphere. This can impact both local and global climates.
92
What are the ways of management of tropical rainforests?
- selective logging and replanting
- Conservation and Education
- Ecotourism
93
What is selective logging and replanting?
Only some trees are cut down (old or inferior tree). New trees are planted in thier place.
94
Describe the method of conservation and eductation in terms of management of tropical rainforests?
Rainforests can be preserved in conservation areas, such as the national parks and nature reserves.
These can be used for education, scientific research and tourism.
95
Describe the method of ecotourism in terms of management of tropical rainforests?
Aims to introduce people to the natural world, to benefit local communities and protect the enviroment for the future.
96
What are the opportunities of the thar desert?
Mineral extraction
Tourism
Energy
97
describe the opportunity of mineral extraction in the thar desert.
the desert region has valuable reserves of minerals which are used all over India and exported across the world.
This most important minerals are gypsum, phospherite and kaolin.
At jaisalmer the Sanu limestone is the main source of limestone for India's steel industry.
98
describe the opportunity of tourism in the thar desert.
In recent years it has become a popular tourist destinatin with tens of thousands visiting the desert each year, many from neighbouring Pakistan. Desert safaries on camels based in Jaisalmer have become popular.
99
describe the opportunity of energy in the thar desert.
- The Thar desert is a rich energy resource.
- There are **extensive lignite coal** deposites and a **thermal energy** plant has been constructed at **Giral.**
- Recently there has been a focus on wind power. The **Jaisalmer wind park** was constructed in **2001**.
- Sunny, cloudless skies offer ideal conditions for solar power generation. At **Bhaleri** solar power is used in **water treatment**.
100
What are the challenges of the Thar desert?
- extreme temperature
- water supply
- accessibility
101
Describe the challenge in the extreme temperature in the Thar desert
the thar desert suffers from extremely high temperature, sometimes exceeding 50 degrees C in the summer
presents challenges for people, animals and plants living in this enviroment.
Working outside in the heat of the day can be very hard.
High rates of evaportaion lead to water shortages
Plants and animals have to adapt to survive in the extreme heat
102
Describe the challenge in the water supply in the Thar desert
As the population has grown and farming and industry have developed, the demand for water has increased.
Water in this region is a scarce resourceThis desert has low annual rainfall, high temperature and strong wind. This causes high rates of evaportation.
103
Describe the challenge in the accessibility in the Thar desert
There is a very limited road network across the Thar desert. This high temperatures can cause the tarmac to melt and the strong winds can often blow sand over the roads. Many places are only accessible by camel, which is a traditional form of transport in the region. Public transport often involves seriously overladen buses.
104
Is the Thar desert managed sustainably?
- desert development programme ~ restire the ecological balance of the region by conserving, developing and harnessing the land, water, live stock and human resources
- tree planting ~ Prosopis Cineraria ~ well suited to hostile conditions of the desert, high quality firewood, building material, follage to feed animals
- sand dunes are very mobile and form a threat to farmland, roads and waterways. ~ planting blocks of trees and establishing shelterbelts of trees and fences alongslide roads and canals.
105
What is the average annual rate of erosion at the Holderness Coast?
around 2 metres per year because the bedrock is made up of till/ boulder clay which is deposited by glaciers around 12000 years ago
106
Describe the holderness coast.
**flamborough head** : the chalk there is a resistant rock that provides examples of erosional features such as caves and stacks. The chalk has formed a headland.
**Mappleton** : the vilage has been subject to intense erosion at a rate of 2.0m per year, resulting in the access road being only 50m from the cliff edge at its closest point. mappleton lies upon unconsolidated (boulder clay)
**Spurn head** : The area forms the southern extremity of the holderness coastand includes a sand shingle spit 5.5km long (it reaches across the humber mouth). This is a depositional feature. It is made of material that has been transported along the Holderness Coast through longshore drift and deposited
107
Describe the formation of a stump.
1. large crack by hydraulic action
2. grows to cave by hydraulic action and abrasion
3. the grows
4. cave breaks through to form an arch
5. arch is eroded and collapses leaving a tall rock stack
6. stack erodes to form a stump
108
Describe the formation of a spit.
- previaling wind pushes waves at an angle of 90 degrees to the beach.
- This moves material along the beach in a zig zag.
- When the coastline changes direction the sediment is continued to deposite in shallow, calm water forming a spit with a salt marsh behind.
- the prevailing wind may change direction when the spit reaches a point and will change the direction of the spit causing it to curve.
109
What are the ways that the holderness coast has used hard engineering to protect its coast?
- Hornsea ~ a sea wall, wooden groynes, rip rap protect the village from erosion and flooding
- Mappleton ~ two rock groynes which cost £2 million and were built to protect the village and a coastal road from erosion and flooding
110
What were the problems with the hard engineering at Hornsea?
they cause problems further down the coast.
- groynes protect the local areas but cause narrow beaches to form further down the Holderness coast, this increases erosion down the coast e.g Cowden Farm which is at risk of falling into the sea.
- Spurn head is at risk of being eroded away because less material is being added to it.
- bays are forming inbetween the protected areas which means that the protected areas are becoming headlands which are being eroded more heavily. This means that maintaining the flood defenses in the protected areas is becoming more expensive.
111
Where is the river tees?
north east of england
112
Describe the upper course of the river tees.
- It flows over hard impermeable rocks.
- The valley has steep sides forming a V-shape valley.
- The river channel is shallow and rocky and the river is turbulent and clear.
- High force water fall and gorge as well as rapids and potholes.
113
Describe high force waterfall in the river tees.
The hard rock at the top of the waterfall is called Whinsill and the softer rock underneath which will be eroded to form a gorge is limestone. There are also river rapdis caused by hard rock in the centre of the river in the upper course
114
Describe the middel course of the river tees.
- gradient becomes less steep
- River begins to erode sideways (lateral erosion) rather than downwards and the river beings to deposite sand and gravel.
- the lateral erosion means that the river gets wider and the river valley gets wider and meanders begin to form
115
Describe the formation of a meander / oxbow lake.
- corrasion and hydraulic power erode the outer bends and deposition builds up the slip-off slopes
- the neck narrows ~ the erosion continues and the neck of the meander narrows. eventually the neck is broken down (normaly coz of flooding)
- the river now follows a straight path. The meander is sealed off by deposition to form the ox-bow lake. The lake may dry up to form a meander scar
116
Descibe the lower course of the river tees.
Close to yarm the river tees has formed very large meanders. Some of these meanders have lead to the formation of oxbow lakes and flooding have caused levees to form. The lateral erosion by meanders and the occasional floods build up a wide, flat flood plain on either side of the river. Here the valley is a broad U-shape with quite gentle sides
117
Describe the formation of a levee.
- levees are high banks of silt along the banks of a river
- formed when the river floods
- coarser material is deposited close to the river channel and the finer material is deposited further away.
- If the river has low flow then it deposites material on the river bed building it up as well.
- the river bed increases until it is higher than the land around so when it floods the water can't go back
118
What is the river basin management of the River tees.
- reduces flooding
- improve water supply
one stratergy is the vuilding of reservoirs such as Cow Green and Grassholme.
In the 19th century, cut offs were built near Stockton to straighten the river for navigation.
119
Why is the river management scheme in the river aire required?
Leeds is on a floodplain of the Aire. Storm Eva in 2015 caused widespread flooding in parts of Yorkshire, including Leeds. The River Aire was normally 0.9 meters was now at 2.95m this affected the city centre and Kirkstall Road Area
120
What is the river Aire a tributory of?
tributory of the River Ouse which eventually joins the Humber estury near Hull
121
Where is the river aires source?
the pennines
122
What are the management schemes of the river Aire?
Strat one: **Moveable wiers**. at Crown Point and Knostrop. They can be lowered to create more room for floor water, with the potential of reducing flood levels by 1m
Strat two: **Merging the river and canal**. The removal of 600m allows the river and canal to merge. This creates additional capacity for flood water, helping lower the levels of flood conditions
Strat three: **Flood walls, lazed with panels and embankments stretching more than 4.5km**. rais its capacity in times of flood
123
How successful was the river management scheme in the river aire?
Social:
+ quality of life improved for people with new green areas and footpaths.
Economic:
+ main routes (+rail lines) will remain open in flood, reducing distruption
~ cost of scheme will be about £100 million when fully complete
+ protecting houses and businesses so financial benefits
Enviromental:
+ thousands of new trees help the enviroment through natural flood management
~ part of the floodplain will be allowed to deliperately food in designated areas if river levels are high.
124
What is the difference between a natural hazard and a natural disaster?
a natural hazard is a natural process which could cause death/ injury/ distruption to human, or destroy properties and possessions (possibility)
a natural disaster is a natural hazard that has acctually happened (has happened)
125
What is an example of a destructive plate margin?
along the west coast of south america, Nazca plate (oceanic) subducted beneath the continental South American. Atacama Trench
126
What land form is made at the top of the continental plate of a destructive boundary?
fold mountains
127
How do constructive plate margins create new crust?
magma rises from the mantle to fill the gap and cools, creating new crust.
128
What is an example of a constructive margin?
the movement of the Eurasian plate and the north american plate away from each other forming the Mid-Atlantic ridge
129
What are the two ways that plates can move next to each other in conservative margins?
----> (slow)
-----> (quick)
____>
<____
130
What is an example of a conservative margin?
The San Andreas Fault, the Pacifc plate is moving in the same directon as the North american but faster.
131
How do volcanoes form at destructive boundaries?
denser oceanic plate melts in the mantle. A pool of magma forms which rises through cracks in crust called vents. When is reaches the surface lava erupts forming a volcanic eruption.
132
How do valcanoes form at constructive boundaries?
the magam rises up into the cap created by the plates moving apart, forming a volcano.
133
What are things that volcanoes emit?
lava, gases and ash.
The ash can cover land, block out sun and form pyroclastic flows.
134
How do earthquakes happen on all three boundaries?
D ~ tension builds when one plate gets stuck as moving below
Cstr ~ tension builds along cracks in the plates as they move away from eachother
Cse ~ tension builds up when plates get stuck grinding past each other
135
How many times worse is a magnitude 7 than a 6 earthquake?
10x
