A-Level Geography
Case Studies and Examples
Physical Geography
Tectonics:
1. Mid Atlantic Ridge – oceanic-oceanic constructive
Ø Extends from North East of Greenland to South Atlantic
Ø Some parts extend above the sea level (e.g. Iceland)
Ø Average spreading rate of 2.5 cm per year
2. East African Rift Valley – continental-continental constructive
Ø About 4,000 miles’ long
Ø Active continental rift
Ø Splitting 2 plates (Somali and Nubian at 6-7 cm per year)
Ø Features: Kilimanjaro and Mount Kenya
3. The Andes – oceanic-continental destructive
Ø From the convergence of the Nazca plate and South American plate
Ø 7,000 km long and 300 km in width
Ø Example of volcano: Cota Paxi
4. Ryukyu Islands – oceanic-oceanic subduction (destructive)
Ø Example: Okinawa
Ø Stretch South West from Kyushu and Taiwan
Ø Eurasian and Filipino plates (subducting plate)
5. Himalayas – continental-continental collision (destructive)
Ø Key features: Mount Everest
Ø The subduction of the Indian plate under the Eurasian plate
Ø Consists mostly uplifted sedimentary and metamorphic rocks
6. Hawaii – hotspots
Ø The Hawaiian Ridge—Emperor Seamount Chain, composed of more than 80
large volcanoes
Ø Example of volcano: Mauna Loa
1
,7. Eyjafjallojokull – MEDC volcano
Ø On the Eurasian plate and North American Plate
Ø Last eruption was in 2011
Ø VIE: 4
Ø In total airlines and associated businesses were losing £130 million per day
8. Nyiragongo – LEDC volcano
Ø Location: The Western branch of the rift valley in the Democratic of Congo
Ø Date of eruption: January 2002
Ø VIE: 1
Ø The death toll reached 140,000 in the first 24 hours
9. 2011 Japan Tsunami – MEDC tsunami
Ø Magnitude 9.0
Ø Death toll: 200,000
Ø Up to 3,000 km of coastline was affected
10. 2004 Indian Ocean Tsunami – LEDC tsunami
Ø The magnitude 9.1 earthquake hit on 26th December 2004
Ø The number of tourists to Phuket dropped by 80% in 2005
Ø 1.7 million people were left homeless
Ø Death toll: 230,000
11. 2011 Christchurch Earthquake – MEDC earthquake
Ø A magnitude 6.3 struck under Christchurch on 22 February 2011
Ø 185 people killed and 170,000 buildings destroyed
Ø The epicentre was 10km to the west of Christchurch
12. 2008 Sichuan Earthquake – NIC earthquake
Ø 7.9 on the Richter scale
Ø Initial death tolls ran at 8,700 but this eventually rose to 69,000
Ø 374,000 people were injured and between 5 million and 11 million people
were made homeless.
Ø 5 million buildings collapsed
Ø The cost for repairing infrastructure was $75 million
13. 2015 Nepal Earthquake – LEDC earthquake
Ø Magnitude of 7.8
Ø The epicentre approx. 80km to the northwest of Kathmandu and its
hypocentre was at a depth of approx. 8.2km
Ø More than 8,000 people killed and 19,000 people injured
2
, Ø Economic losses at 9% to 50% of gross domestic product
14. 2010 Haiti Earthquake – LEDC earthquake
Ø The focus of the earthquake was 13km below the surface of the earth
Ø Magnitude 7.0
Ø 3.5 million people affected
Ø 220,000 people killed
Ø Over 188,383 houses were badly damaged and 105,000 destroyed
15. California – disaster hotspot (earthquakes, droughts, landslides, tsunamis and
volcanoes)
Ø California has 2 or 3 earthquakes each year (5.5+ on the Richter scale)
Ø Droughts can be caused by increased wind blowing westward from the desert
areas that are east of California – the most devastating effect is wildfires – can
quickly spread over wide areas (the wildfires in Southern California in 2007
killed 22 people and destroyed 1,300 homes)
Ø Earthquakes under the Pacific Ocean could cause a tsunami along the
California coastline
Ø But there are potential for future eruptions, e.g. Lassen peak, Mount Shasta
and volcanoes around Mammoth Lake
16. Japan Sea Walls – modifying the event
Ø About 43% of Japan’s nearly 30,000 km of coastlines are lined with sea walls
or other structures designed to protect the country against high waves,
typhoons or even tsunamis – over 400 of concrete sea walls
Ø It costs $1.5 billion to construct these sea walls
17. Italy’s Lava Diversion – modifying the event
Ø It’s estimated these barriers cost $5-25 million to build
18. The Japanese Meteorological Agency – modifying vulnerability (earthquakes and
tsunamis)
Ø It detected the earthquake and issued televised warnings just after the very
rapid P-waves that arrived but before the more damaging S-waves
Ø It also predicted the tsunami from this event just 3 minutes after the major
earthquake, giving people time to get to safety
19. Volcanoes – modifying vulnerability
Ø The design of a building can do little to resist lava, pyroclastic flows and lahars
Ø Various physical processes can be monitored for changes which can signal
eruptions and past eruptions (can predict where risks are highest)
3
Case Studies and Examples
Physical Geography
Tectonics:
1. Mid Atlantic Ridge – oceanic-oceanic constructive
Ø Extends from North East of Greenland to South Atlantic
Ø Some parts extend above the sea level (e.g. Iceland)
Ø Average spreading rate of 2.5 cm per year
2. East African Rift Valley – continental-continental constructive
Ø About 4,000 miles’ long
Ø Active continental rift
Ø Splitting 2 plates (Somali and Nubian at 6-7 cm per year)
Ø Features: Kilimanjaro and Mount Kenya
3. The Andes – oceanic-continental destructive
Ø From the convergence of the Nazca plate and South American plate
Ø 7,000 km long and 300 km in width
Ø Example of volcano: Cota Paxi
4. Ryukyu Islands – oceanic-oceanic subduction (destructive)
Ø Example: Okinawa
Ø Stretch South West from Kyushu and Taiwan
Ø Eurasian and Filipino plates (subducting plate)
5. Himalayas – continental-continental collision (destructive)
Ø Key features: Mount Everest
Ø The subduction of the Indian plate under the Eurasian plate
Ø Consists mostly uplifted sedimentary and metamorphic rocks
6. Hawaii – hotspots
Ø The Hawaiian Ridge—Emperor Seamount Chain, composed of more than 80
large volcanoes
Ø Example of volcano: Mauna Loa
1
,7. Eyjafjallojokull – MEDC volcano
Ø On the Eurasian plate and North American Plate
Ø Last eruption was in 2011
Ø VIE: 4
Ø In total airlines and associated businesses were losing £130 million per day
8. Nyiragongo – LEDC volcano
Ø Location: The Western branch of the rift valley in the Democratic of Congo
Ø Date of eruption: January 2002
Ø VIE: 1
Ø The death toll reached 140,000 in the first 24 hours
9. 2011 Japan Tsunami – MEDC tsunami
Ø Magnitude 9.0
Ø Death toll: 200,000
Ø Up to 3,000 km of coastline was affected
10. 2004 Indian Ocean Tsunami – LEDC tsunami
Ø The magnitude 9.1 earthquake hit on 26th December 2004
Ø The number of tourists to Phuket dropped by 80% in 2005
Ø 1.7 million people were left homeless
Ø Death toll: 230,000
11. 2011 Christchurch Earthquake – MEDC earthquake
Ø A magnitude 6.3 struck under Christchurch on 22 February 2011
Ø 185 people killed and 170,000 buildings destroyed
Ø The epicentre was 10km to the west of Christchurch
12. 2008 Sichuan Earthquake – NIC earthquake
Ø 7.9 on the Richter scale
Ø Initial death tolls ran at 8,700 but this eventually rose to 69,000
Ø 374,000 people were injured and between 5 million and 11 million people
were made homeless.
Ø 5 million buildings collapsed
Ø The cost for repairing infrastructure was $75 million
13. 2015 Nepal Earthquake – LEDC earthquake
Ø Magnitude of 7.8
Ø The epicentre approx. 80km to the northwest of Kathmandu and its
hypocentre was at a depth of approx. 8.2km
Ø More than 8,000 people killed and 19,000 people injured
2
, Ø Economic losses at 9% to 50% of gross domestic product
14. 2010 Haiti Earthquake – LEDC earthquake
Ø The focus of the earthquake was 13km below the surface of the earth
Ø Magnitude 7.0
Ø 3.5 million people affected
Ø 220,000 people killed
Ø Over 188,383 houses were badly damaged and 105,000 destroyed
15. California – disaster hotspot (earthquakes, droughts, landslides, tsunamis and
volcanoes)
Ø California has 2 or 3 earthquakes each year (5.5+ on the Richter scale)
Ø Droughts can be caused by increased wind blowing westward from the desert
areas that are east of California – the most devastating effect is wildfires – can
quickly spread over wide areas (the wildfires in Southern California in 2007
killed 22 people and destroyed 1,300 homes)
Ø Earthquakes under the Pacific Ocean could cause a tsunami along the
California coastline
Ø But there are potential for future eruptions, e.g. Lassen peak, Mount Shasta
and volcanoes around Mammoth Lake
16. Japan Sea Walls – modifying the event
Ø About 43% of Japan’s nearly 30,000 km of coastlines are lined with sea walls
or other structures designed to protect the country against high waves,
typhoons or even tsunamis – over 400 of concrete sea walls
Ø It costs $1.5 billion to construct these sea walls
17. Italy’s Lava Diversion – modifying the event
Ø It’s estimated these barriers cost $5-25 million to build
18. The Japanese Meteorological Agency – modifying vulnerability (earthquakes and
tsunamis)
Ø It detected the earthquake and issued televised warnings just after the very
rapid P-waves that arrived but before the more damaging S-waves
Ø It also predicted the tsunami from this event just 3 minutes after the major
earthquake, giving people time to get to safety
19. Volcanoes – modifying vulnerability
Ø The design of a building can do little to resist lava, pyroclastic flows and lahars
Ø Various physical processes can be monitored for changes which can signal
eruptions and past eruptions (can predict where risks are highest)
3
