All of Hazardous Earth case studies Flashcards
(37 cards)
1
Q
4.a. Facts about Hawaii
A
- The state encompasses the Hawaiian archipelago, with islands spread over 1,500 miles
- Formed by hot spots under the Pacific plate, where magma plumes rise up to the Earth’s surface and cools, forming masses of land
- As the plate moves northwest, the static hotspot forms another island and the previous island becomes ‘extinct’ as its source of magma is lost
- Majority of people live on O’ahu as it is extinct, although it is more expensive than the active Island of Hawaii
- Effusive eruption by Kilauea (shield volcano) in Hawaii has been continuous since 1983
2
Q
4.a. Reasons why people choose to live in tectonically active locations (Hawaii)
A
- Homes near volcanoes are often cheaper, residents can still appreciate the natural beauty of Hawaii and oceanfront homes
- People may become stuck in the area as their assets are fixed and they don’t have the capital to move elsewhere
- The islands have good weather and a strong community
3
Q
4.a. The impacts people experience as a result of volcanic eruptions (Hawaii)
A
People lose their homes and due to lack of insurance can lose their capital and are therefore unable to move elsewhere
- The community is impacted as residents have to move elsewhere, although often for the short term
- Evacuation has to occur that can be emotionally difficult, discourages people to move to the area, net migration
4
Q
4.a. Economic, environmental and political impacts on the country (Hawaii)
A
- Infrastructure is damaged and requires government intervention to help rebuild
- People’s assets are lost, potentially more reliant on loans to help rebuild
- If they don’t rebuild in time to complete their new home and place insurance on it, they will lose all money
- Relocation and evacuation costs the government in addition to rebuilding
- Trees and vegetation were burnt by the slow-moving magma, habitats also destroyed and the lava smothered land
- However there are positives as lava generates tourism in the area, benefits economically but also socially (creates jobs)
5
Q
4.a. Analysis (extent of impacts) (Hawaii)
A
- The US is an AC, so the government is capable of sourcing its own aid to send out to Hawaii
- Therefore, minimal impact globally as it is more of a localised issue
- The effusive eruption is not acutely hazardous to life
- As this is a common occurrence (30 year eruption), resilience is easier to obtain and local people are more educated about the impacts
- The majority of the population do live in O’ahu so number of people impacted is relatively localised
6
Q
4.a. Facts about Merapi
A
- Mount Merapi is an active stratovolcano located in Indonesia
- It is the most active volcano of the area and has erupted regularly since 1548
- The volcano is located at a subduction zone, where the Indo-Australian plate subducts underneath the Eurasian plate
- It is located approximately 17 miles North of Yogyakarta city which has a population of 2.4 million
- Indonesia has suffered more eruptions causing fatalities and damage to infrastructure than any other country in the world
- The most recent eruption occurred in October/November 2010 at a VEI scale of 3-4
7
Q
4.a. Reasons why people choose to live in tectonically active locations (Merapi)
A
- High levels of poverty in Indonesia means that people have minimal choice as to where they live
- It is cheaper to live by the volcano and the lack of land in Indonesia leads to overcrowding
- As Indonesia is a LIDC, the economy is heavily dependent on agriculture so many people are subsistence farmers
- The fertile soils provided on the flanks of the volcano are very beneficial to farming and is a reason why people may wish to live there
8
Q
4.a. The impacts people experience as a result of volcanic eruptions (Merapi)
A
- 357 people were killed by the eruption in 2010, mainly due to the pyroclastic flows and lava bombs thrown from the volcano
- Approximately 410,000 people in the vicinity became refugees (enhanced due to dense population) which increases the risk of disease and poverty
- Communities severely impacted and disrupted, very upsetting
9
Q
4.a. Economic, environmental and political impacts on the country (Merapi)
A
Livestock was killed and agriculture smothered, worsened by the acid rain that followed from the SO2 released by the eruption
- Lack of food stability led to more cases of starvation whilst destabilising the agricultural economy
- Those left without homes needed additional help from the government, but the government’s capability to give this aid is significantly reduced (LIDC)
- Infrastructure was destroyed and needed rebuilding, isolating communities as road connections were blocked which made aid provision harder to give
10
Q
4.a. Analysis (extent of impacts) (Merapi)
A
- The impacts of the 2010 eruption were felt globally on a larger scale as the Indonesian government were unable to provide their own aid
- International help was required which had a global response
- In the short term, agriculture was devastated by pyroclastic flows and had a negative effect on the economy
- Once the ash had settled, this enhanced soil fertility and improved the crop production in the following year
- However, due to the population density of Indonesia, the extent of the number of refugees caused a profound rift in demographics
11
Q
4.b. Facts about Japan
A
- Japan is an archipelago
- The region is based on a subduction zone (destructive convergent boundary) in the ‘Ring of Fire’
- Japan is very tectonically active, with 400 earthquakes occurring every day
- The Pacific coastal zone is particularly heavily populated and contains 3 large urban areas: Tokyo (36 million), Osaka (19 million) and Nagoya (9 million)
- The 2011 Tohoku Earthquake occurred in the boundary between the Pacific and North American plates, with an epicentre 70km offshore
12
Q
4.b. Reasons why people choose to live in tectonically active locations (Japan)
A
- Japan has very good preparation systems, buildings are structured well and have warning systems so many residents may not feel as if there is a large threat
- Generations of families may have lived in the area and do not wish to move
- Historical/cultural reasons for remaining in the country
- Japan has the potential for geothermal energy stemming from the tectonic activity, this provides jobs and research opportunities
13
Q
4.b. The impacts people experience as a result of earthquake activity (Japan)
A
- The EQ itself had relatively minimal impacts, mainly causing injuries - however, the tsunami caused by the quake led to the death of 16,000 people
- 465,000 people were displaced and had to be relocated
- 100,000 children lost at the time, very traumatic for families
- 4.4 million households left without electricity, isolating many people who rely on the technology
14
Q
4.b. Economic, environmental and political impacts on the country (Japan)
A
- Cost the economy $360 billion
- Loss of infrastructure and buildings meant rebuilds had to occur quickly, original buildings were expensive and had higher investment as Japan is an AC
- Liquefaction during EQ caused drowning of parks and grassland
- Low-lying areas such as Sendai were badly affected by tsunami as water could move unimpeded and wash over agriculture
- Fukushima Nuclear Reactor went into meltdown and released radioactive waste into the Pacific
- This caused a political uproar as Japan was slandered for using nuclear energy
15
Q
4.b. Analysis (extent of impacts) (Japan)
A
- The economic impacts for Japan were more severe, due to the higher level of built-up areas impacted and the concentration of expensive infrastructure and buildings
- The newer technologies of Fukushima brought a widespread disaster on a larger, global scale
- The political backlash was exaggerated as the Fukushima disaster was international news
- However, Japan was able to source money for itself instead of requiring international aid due to its AC status, reducing the global impact
- The impact on people was widespread, however this was mainly due to the tsunami and not the initial EQ
- Despite good education and preparation schemes, not much could have been done to reduce lives lost from the tsunami, as even the 10m wall in Miyako subsided and let water through
16
Q
4.b. Facts about Nepal
A
- Nepal is situated in the middle of the collision zone where the Indo-Australian plate meets the Eurasian place in a convergent collision boundary
- As the plates collide, pressures build up and energy is released as earthquakes
- A 7.8Mw EQ occurred on 25th April 2015 due to a slip along the main frontal thrust fault in the collision zone
- The epicentre was 90km northeast of Kathmandu, the capital of Nepal
17
Q
4.b. Reasons why people choose to live in tectonically active locations (Nepal)
A
As Nepal is a LIDC, many residents will not have the resources to move away or are incapable of doing so due to poor infrastructure
- Lack of education, large earthquakes are not frequent (around every 40 - 80 years) so people may not realise there is a threat
- Subsistence farming is very prominent in Nepal’s economy, farmers may have large plots of land and do not wish to leave
- Family tradition/historical/cultural reasons for remaining in the area
18
Q
4.b. The impacts people experience as a result of earthquake activity (Nepal)
A
- 8,800 fatalities with another 22,000 people injured
- 2.8 million people were displaced
- Many people had to move to temporary shelters, likely to enhance the spread of disease
- 473,000 homes were destroyed, permanent relocation due to incapability to rebuild
- Several culturally important locations were lost such as the Dharahara tower
- Single women were disadvantaged for aid as most aid was controlled by men, inequalities
19
Q
4.b. Economic, environmental and political impacts on the country (Nepal)
A
- Costs to the country’s economy were $10 billion, which is significant as Nepal has a much smaller economy
- Nepal’s government lacked the resources to cope, requiring international aid and a global response
- Avalanches in the mountains smothered habitats and land, destroying the environment
- The timing of the EQ disrupted the planting season, Nepal relies heavily on subsistence farming (third of GDP)
- Nepal’s political instability worsened due to the EQ, which was already poor due to recent problems with the democracy of the region, including coups
20
Q
4.b. Analysis (extent of impacts) (Nepal)
A
- Nepal’s economic impacts were felt more globally, as the call for international aid was required
- As Nepal is more heavily reliant on agriculture, the environmental impacts hit the country harder
- Poorer infrastructure and connectivity meant people were not prepared and aid was harder to get to certain areas
- As the population density is nearly half of that of Japan, the concentration of people impacted was less
21
Q
5.a. Attempts to mitigate against the event, such as lava diversion channels (Hawaii)
A
- Kilauea is monitored by the USGS and the Hawaiian Volcano Observatory (HVO) in order to gain knowledge of potential eruptions and lava pathways
- Lava can be sprayed to cool it and solidify, preventing spread onto habited land as the eruption is effusive
22
Q
5.a. Attempts to mitigate against vulnerability such as community preparedness (Hawaii)
A
- Risk land zoning (Hazard Zone Map) is used to ensure residents are aware of risks before buying homes and helping the government know where to allocate resources
- People in higher-risk areas are advised to have more preparation in place
- Government evacuations are in place
- Road closures can be formed if there is an area are risk of lava flow
- Community organisations can have a representative from HVO to discuss matters more directly, can call up to ask for help (better connectivity)
23
Q
5.a. Attempts to mitigate against losses, such as rescue and emergency relief (Hawaii)
A
- Government aid (USAid) is available and ready for situations as it can be sent over from the mainland
- Even though it is expensive, the US is capable of getting the funds to bring help when needed, not a global affair
- Insurance can be provided to homes in the vicinity of volcanoes, so there is a capability to regain capital and rebuild
24
Q
5.a. Analysis (do these methods work?) (Hawaii)
A
- Despite warnings, people are still in danger as they cannot stop the flow of lava from reaching buildings/homes, although it does discourage people living in concerning areas
- If people have lived in their homes for a long period of time, their emotional attachment will often prevent them from wanting to move
- Not all insurance is valid, especially if people have not fully finished rebuilding their homes from the last disaster
25
5.a. Attempts to mitigate against the event, such as lava diversion channels (Merapi)
- Monitored by the Centre of Volcanology and Geological Hazards (CVGHM)
- The National Agency for Disaster Management has lahar sensors and uses CCTV to monitor high risk areas
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5.a. Attempts to mitigate against vulnerability such as community preparedness (Merapi)
- After the 2010 eruption, new spatial planning was necessary to be performed
- The Government of Indonesia initiated to redesign residential areas, especially around the high-risk slopes of Merapi
- Villagers on southern slopes have been encouraged to move, in some cases receiving financial assistance
- The CVGHM works closely with local governments to improve community preparedness, advising them on mitigation strategies
27
5.a. Attempts to mitigate against losses, such as rescue and emergency relief (Merapi)
- Military and experienced search-and-rescue teams are deployed that are relatively well-equipped
- Temporary shelters in safe zones are available in case of evacuation and sometimes these are upgraded to permanent areas
- A year after the 2010 eruption, around 2,000 villagers are still living in temporary homes
- The government has accelerated the process of cleaning the rivers from the pile of volcanic material, providing work for local companies to transport deposits out of rivers
- This is beneficial as inhabitants can make profit from the volcanic material (fertility) and the government gets revenue
28
5.a. Analysis (do these methods work?) (Merapi)
- In the past, funding in the CVGHM has been poor but has improved recently
- Despite this, warnings to isolated villages due to the reduced connectivity is difficult
- Villagers still may not wish to move from hazardous areas due to religious/historical reasons
- Majority of mitigation of losses stem from short term improvements and not in the long term, as villagers are still living in temporary homes
- Excess numbers of people in temporary homes may lead to the spread of disease
29
5.b. Attempts to mitigate against the event such as land-use zoning (Japan)
- Monitored by the Japan Meteorological Agency, providing information and warnings of impending EQs
- Tsunami warning systems off the coast and the building of a 10m sea wall in Miyako
- Land use zoning provides open spaces where people can accumulate after an EQ and not be at risk of falling debris
- Source modelling and prediction of seismic motion, risk assessment of slope failures
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5.b. Attempts to mitigate against vulnerability such as building design (Japan)
- Buildings with aseismic design have been incorporated, eg. providing steel frames and braces capable of moving without collapsing, shock absorbers, deep foundations, strapping furniture to walls etc
- Fire proofing older buildings
- Preventing/controlling building in locations susceptible to excessive ground shaking or liquefaction
- Community preparedness, ongoing education and early warning systems detected by P waves
31
5.b. Attempts to mitigate against losses such as insurance (Japan)
- Japan has vast resources to manage losses
- Recovery and reconstruction plans are very well organised
32
5.b. Analysis (do these methods work?) (Japan)
- The sea walls are not always effective, due to subsidence the 10m wall was washed over by the waves in Miyako
- Not all buildings are designed in an aseismic way, often building collapse has to occur first before aseismic rebuilds can take place (very expensive)
- Due to high density of buildings, one collapse can cause a ricochet effect
- Despite the vast resources Japan has, the high population density and number of people concentrated in cities, increases the effects of seismic activity
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5.b. Attempts to mitigate against the event such as land-use zoning (Nepal)
- National Seismological Centre monitors activity monthly, however it is difficult to modify EQs
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5.b. Attempts to mitigate against vulnerability such as building design (Nepal)
- Building codes were introduced by conducting training and raising awareness on seismically safer construction
- Encouraging households to have a 'go-bag' containing items useful in an earthquake emergency
- Introducing an annual 'Earthquake Awareness Day' and education programs
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5.b. Attempts to mitigate against losses such as insurance (Nepal)
- Due to Nepal's poorer developmental status, 330 humanitarian agencies were involved in the 2015 EQ including the UN, EU, Shelter and the Red Cross as Nepal was incapable of getting resources itself
36
5.b. Analysis (do these methods work?) (Nepal)
- There is no formal alarm system that is easily accessible as it is in Japan (eg. Phone alert) due to poor access to technology, it is harder to warn people
- Residents may not adhere to the building codes, often because they don't have the resources/capital to achieve this
- Rapidly expanding informal settlements meant that governments were unable to enforce building regulations
- Older buildings had unreinforced masonry due to the lack of frequent EQs, meaning they could not withstand the ground shaking
- External help may take a while to get across to Nepal, particularly as infrastructure is not as developed, especially in mountainous regions were villages were isolated
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