CASE STUDIES - PHYSICAL Flashcards
SAHEL DROUGHT
CAUSES (Physical):
•Lack of orographic rainfall, Sahel is very flat
•High pressure zone - subtropical latitude of Sahel means that it typically has a high atmospheric pressure, meaning air sinks
•El Nino Southern Oscillation (ENSO)
•La Nina (2011) unusually strong La Niña interrupted seasonal rain in E.Africa
HUMAN CAUSES:
•Rapidly growing pop, doubled every 20-30 yrs
•Deforestation, less atmospheric moisture
•Overgrazing + over-cultivation
IMPACTS (ECON)
•In 1973, 25% of livestock died
•25% fall in agric production since 2010
•Rising land prices -20-60% in Sahel over 5 yrs
SOCIAL: 100,000 dead
3 GORGES DAM
PROS: Can reduce frequency of downstream flooding from once every 10 yrs to every 100 •Sustainable energy CONS: •1.3m people relocated from 1500 Villages and towns •Reservoirs water quality is low •Can trigger EQ's + landslides
TROPICAL RAINFOREST - BIOME CASE STUDY
BACKGROUND: A single hectare may contain 42,000 different species of insect, up to 807 trees of 313 species and 1500 specified of higher plants
RAINFALL: Annual=Over 2000mm per year
•Rainfall is high - totals can double when the sun/ITCZ is directly overhead at spring and autumn
-Contrast uplift of warm, unstable air is caused by the ITCZ, causing low pressure throughout the year
SOIL: Constant supply of minerals from rock to the soil
•Ferrallitisarion (breakdown of chemical weathering) creates clay minerals
KOBE EQ
- More than 5000 died
- HDI=0.953
- GDP Per Capita=$22475.48
- 300,000 homeless
- More than 12,000 buildings destroyed
- Cost to rebuild = 100bn
- The centre was worst affected. This is cos it was built on easily moving ground which LIQUIFIED
HAITI 2010 - Pop=9.7m
•GDP per capita=$343 •HDI=0.456 •3,500,000 were affected •220,000 dead •300,000 injured •1.5m homeless •4000 schools damaged 7 MAGNITUDE
CHRIST CHURCH 2011 EQ
- Magnitude of 6.3
- GDP Per Capita=$27,700
- Adult literacy rate 99%
- 100% have access to clean water
- Liquefaction
- 185 dead
- 2000 injured
- 1/5 lost their jobs
- 40bn worth of damage
MOUNT SOUFRIERE HILLS 1997
PT.1
Eruption began in 1995 and is ongoing
Activity monitored by Montserrat Volcano Observatory
-Over 30,000 EQ’s have been recorded
-Ground movement converted to radio signals then transmitted to MVO
-Ground deformation monitoring using Global Positioning System (GPS). Using a constellation of satellites and radio waves
-Environmental monitoring, assessing the gas released from the volcano. Measurements of amount of gas + ash emitted, gives insight into eruption behaviour
-Rainwater collection: chemical composition of the water is highly dependant in amount of gases being emitted from the volcano
MT SOUFRIERE HILLS 1997 volcano
PT.2
19 killed, Lahar destroyed large areas of Montserrat
-Short term responses
•Evacuation, abandonment of capital city, British gov have money for compensation
-Long term
•Ab exclusion zone set up in volcanic region
•Volcanic observatory built to monitor
•Soil fertility improved due to ash deposits
S.E.ASIA 2004 Tsunami
EQ caused the tsunami, which involved the subduction of Ino-Australian plate (Oceanic) under the Eurasian plate (Continental)
-The uplift of sea floor caused displacement of billions of tonnes of water
•Killed people in 14 different counties (Over 250,000)
•500,000 homeless
•Over 80,000 homes destroyed
RESPONSES (short term)
•Over $7bn provided by govs + NGOs in aid
•5m had to be relocated into camps
LONG TERM-
•Tsunami early warning system installed in Indian Ocean costing $20m
JAPAN 2011 TSUNAMI
Magnitude of 9
Reason: build-up in strain energy as the Pacific plate subducted under Eurasian
•15,853 deaths
•6000 injured
•300,000 buildings destroyed
•Damage cost $235bn
BEFORE: 40% of Japan had sea walls of up to 10m, GDP=$34,000
RESPONSES (SHORT TERM) -
•over 340,000 displaced people in region needed food, water + shelter
•Japanese Red Cross provided $1bn in donations
(Coasts/tectonics)
Tsunami Boxing Day 2004
9 of Richter scale •over 100x bigger than Kobe EQ •Travelled at 800km/he •17m high wave hit Sri Lanka - 31,000 deaths •Total=289,000 deaths (56% children)
(Coasts)
1953 Storm Surge
+
THAMES ESTUARY
Water level exceeded 5.6m
•In ENG., 307 dead
•U.K. Constructed storm surge barrier on Thames
THANES ESTUARY:
Thames gateway is at risk of storm surges
•1.25m at risk of floods
•Sea level rise expected 26-86cm by 2080
Sichuan EQ - EQ disaster in an LEDC
CAUSES: Indian plate colliding with Eurasian •Occurred May 2008 •7.9 on Richter scale in an area with 43m people DEATHS: •69,000 •374,000 injured, 5-11m homeless •5m buildings collapsed •cost of repairing communications=$75m •$100m raises from Red Cross
Tar sands in Alberta
Extraction can lead to 3x normal amount of CO2 emissions
POSITIVES:
•$3.56bn in 2012-13
•over next 25 years, Alberta can expect $350bn
•affects the jobs of 112,000 + 500,000
Jobs over next 25 years
NEGATIVES:
•Greenhouse gas 1.3m car equivalent a day
•1/160 litres leaks
Eyjafajokull Iceland Case Study
It’s the name of the glacier
•Iceland is located on the North American plate and Eurasian plate—> creating a divergent plate boundary
ERUPTION: (20th March) ash plume rising 11,000m into air
EFFECTS: 150m ice cap melted which caused major flooding to Iceland, 700 evacuated
SECONDADY EFFECTS: 96,000 flights cancelled
•cost airlines $200m+ per day
