tectonics Flashcards
How earthquakes can have different impacts in different countries
New Zealand: 2011
- transform fault line
-manufacturing zone located outside the major cities, so it was undamaged
- 185 fatalities
-80% of water and sewage systems damaged
-10,000 homes required demolition
- 16.5 billion dollar loss
-80% of buildings in the CBD were damaged
- tourism decreased by 40%
- extensive liquefaction
-6.2Mw
China:2008
-a collision between Indian and Eurasian plate
- a high economic loss
- 69,000 fatalities, buildings not up to local regulations, corruption
- 5 million were made homeless
- $150 billion loss
large mudslides due to destabilisation
- livestock loss
-8Mw
Nepal:2015
-22,000 fatalities
- 3 million made homeless
-loss of $5 billion
- tourism numbers dropped heavily
-aftershocks caused mudslides
-rockslides
-avalanches
-7.9Mw
How tsunamis can have different impacts in different countries
Japan:2011
- 16,000 fatalities
-127,500 homes destroyed
-4.4 million homes lost their electricity
-$300 billion cost to the Japanese economy
-large scale infrastructure damage
-damage to 2 nuclear plants at Fukushima
-saline water floods
-subduction
-9Mw
Chile:2010
- 150 fatalities
- shortages of food and necessities led to looting
-loss of $15 billion
-port badly damaged
-fishing and tourism industries affected
- sewage leaks
- debris dumped into fragile wetland
-subduction
-8.8Mw
Indonesia:2004
-230,000 fatalities
- 1.7 million made homeless around the Indian coastline.
- economic cost of $15 billion
- destruction to the fishing industry
- the destruction of coral reefs
-coastal mangroves flattened
- freshwater supplies contaminated by the encroachment of saltwater.
-fault movement, conservative
-9.2 Mw
How volcanos can have different impacts in different countries
USA (Mount St Helen):1980
-57 fatalities
- poor visibility caused closed highways for over a week
-commercial flights cancelled
- estimated loss of $3.4 billion
- harvest was lost
- 9.4 million m^3 of timber destroyed, widespread job loss
- glacial melt produced lahars
-landslide
- thousands of trees were uprooted from the initial blast
-destructive, subduction plate movement
Indonesia:2010
-353 fatalities
-70,000 people permanently displaced
- respiratory problems amongst locals
- large-scale disruption to airlines
- $781 million loss
- heavy ash fall caused crops to flatten
- food prices increased
- pyroclastic flow wiped out the rainforest
- lava flowed into a major river, affecting their flow
-destructive, subduction plate movement
DR Congo: 2002
-civil unrest led to a lack of priority for volcanic monitoring.
- 120,000 made homeless
- cholera spread
- $1.2 billion USD loss
- destroyed 15% of the city of Goya
-tephra emitted
- divergent plate boundary
Philliphines- multi-hazard zone
Main problems faced:
- It sits across a major plate boundary, so risks from volcanoes, destructive boundaries
and earthquakes
-Its northern and eastern coasts face the Pacific, the world’s
most tsunami-prone ocean.
- It lies within south-east Asia’s major typhoon belts. In most
years, it is affected by 15 typhoons and struck by 5 or 6 of
them.
- Landslides are common in mountain districts due to
deforestation of many hillsides
- Lower middle-income country - rapidly growing population -
high population densities - especially coastal regions
- Droughts -these occur when the wet season (may-Oct)
hasn’t brought enough rain to last the dry season. In 2005 the reduction in rainfall decreased
the water flow in rivers, which affected power production from HEP plants.
- Flooding - during the wet season, floods can be caused by typhoons and heavy rain
Philippines- multi-hazard zone
Mount Pinatubo 1991:
- 350 people died, including 77 in the lahars that occurred.
- Some evacuees died in camps, where they were exposed to disease
- 80 000 hectares of farmland were buried beneath ash, disrupting the livelihoods of 500 000
farmers and their family members
- Economic losses were US$710 million mainly for agriculture and property
Haiti
-2010, it experienced an earthquake of a Richter scale of 7
-230,000 people died
- result of 2 conservative strike-slip faults on the island
-6900 people died from cholera
-60% of infrastructure destroyed
-
Haiti 2010
-2010, it experienced an earthquake of a Richter scale of 7
-230,000 people died
- the result of 2 conservative strike-slip faults on the island
-6900 people died from cholera
-60% of infrastructure destroyed
- $ 8 billion damage
-all hospitals destroyed
-reliant on NGO
- only airport runway was destroyed.
Japan 2011 earthquake and Tsunami
-15,845 people died
-movement along the subduction zone between the pacific and north American plate
- some parts of Japan shifted 2.4m east
-flooding
-cost $300 billion
-nuclear reactor damaged
-128,000 properties damaged
-soil liquidfaction
Indian Ocean 2004
- it the impact is inevitable no matter how much mitigation or preparation was done due to its sheer size
-280,000 people died.
-caused by underwater earthquakes, subduction of a plate
-1500 villages in Sumatra lost
-affected coastal settlement - fishermen in Tamil Nadu lost their lives
- rice field destroyed in Sri Lanka
-drinking water contamianted
-coastal water and coral reefs destroyed
Iceland 2010
- 0 deaths
- mid atlantic ridge
- ash ejected into the atmosphere caused lava to react with surface ice
-local flooding as glaciers were melted - fresh fix exports exported
- livestock affected
-all flights cancelled due to ash cloud
-$2.6 billion of GDP lost
-divergent plate boundary
Volcanic eruptions
Basaltic lava:
-shield volcanos
-slower movement
-low silica content - 50%
- less violent explosions
-viscous
-1000-1200°c
-constructive plate boundaries
Acidic lava:
Composite volcanos
-found in destructive plate boundaries
-2 types of lava: Andesitic and Rhyolitic lava
- Andesitic lava- 800-1000°c
-Rhyolitic lava-650-800°c
-70% silica content
- very violent eruption
- not visous
risk poverty nexus
- poverty is a contributing factor and consequence of natural hazards. This can cause a positive feedback mechanism which can cause further economic loss.
-less development = more vunruble
hazard profiles
They compare the physical processes of all hazards and help decision-makers identify and rank the hazard.
Characteristics include:
-speed of onset
-duration
-Arial extent
-spatial predictability
- frequency
