TECTONIC CASE STUDIES Flashcards
What occured in Nepal in 2015 and what caused it?
7.8 magnitude earthquake hit Nepal in 2015. Nepal located on south asia between india & china sitting on boundry between indian and eurasian plates. As plates push against each other, pressure builds up due to friction. Earthquake was a result of a release of this pressure.
where was the epicentre and What were the immediate impacts of the Nepalese earthquake?
The epicentre was 80km northwest of Kathmandu. The initial earthquake and aftershocks killed a total of 6333 people with 21,000 injured and 3mil homeless.
Why was the earthquake so disasterous?
Low pop density but most damage was done in Kathmandu.
> Vulnerable country was 1 of the poorest countries in 2016 so unprepared for the earthquake
> Weak infrastructure was severely damaged or destroyed in the area of the earthquake.
> most of Kathmandu’s buildings were not built to withstand earthquakes and many collapsed
increasing the difficulty of rescues
> nepals emergency service not able to cope with the level of destruction thus relying on aid.
> Tourism fell costing 5$ billion and 25% of its GDP.
> US 6.6 billion from aid used for rebuilding with scientists believing not all pressure released and another big earthquake is coming.
What was the 1989 Loma Prieta earthquake and why was it so devastating?
6.9 mag earthquake hit near san franscisco with city marina district suffering worst of damage.
> built on a man-made landfill, areas soft, sandy soil amplified ground shaking increasing damage experienced by buildings
> with sandy soil liquifing causing buildings to collapse.
Why was the Eyjafjallajokull (EFJ) earthquake of 2010 so significant?
Flights cancelled for a week as pyroclastic flows threatened to clog aircraft engines and stop them working. Eruption had social & economic impacts across europe
> with 100,000 flights cancelled worldwide,
> 10mil + passengers stranded or unable to board flights
> Worldwide airlines lost 1.7 billion in rev
> Europe’s economy lost $ 5 billion
> 20% of kenyas economy based on green veg export when flights cancelled kenyan businesses forced to dump 1.3mil tonnes of veg and flowers.
WHat happened in Monserrat in 1995?
Part of the island arc in the Caribbean sea formed where the Atlantic plate subducts beneath the Caribbean plate, only 16km long and 10km wide with rock entirely volcanic.
> In 1995 soufriere hill volcano erupted into an ash-cloud, these eruptions continued with pyroclastic flows affecting much of the island.
What were the consequences of the monseratt volcanic eruptions?
Caused dozens of people to lose their lives with 7000 moving to other countries.
> Plymouth the capital destroyed which contained many of the main services
> 2/3 of houses & 3 quarters of infrastructure
> Unemployment increased as the tourist industry and agriculture collapsed.
> Top heavy pyramid as younger pop left older pop behind.
> 2/3 of volacano unihabitable, observstory built to monitor Monseratt
> Trying to rebuild tourist industry
Where and what was the Indian ocean tsunami of 2004 (boxing day) ?
Earthquake of the coast of Sumatra Indonesia magnitude of 9.3 thrust and heaved the floor of the Indian ocean toward indionesia 15 meters sending out shockwaves, waves that struck the shallow coastline almost 17 M near banda ache. size and speed of the earthquake meant an astonishing nb of countries hit affecting 5 million and killing 300,000 people with 1.7 mil homeless.
How long it did it take to hit different regions?
> 15 mins after the earthquake tsunami hit Sumatra leaving 700,000 people homeless
After 60 mins tourists in malaysia hit.
After 90 mins thailand hit killing 1700 tourists from 36 countries
After 2 hours sri-lanka hit with shallow waves causing wave refraction killing 4000 and leaving 1mil homeless.
India hit 3km inland leaving 376,000 homeless
Maldives then hit 20 of 199 inhabited islands however impact mitigated by coral and the absence of a continetal shelf
Schecelles & Madacascar then hit then somalia where 2000 buildings were destroyed/
In Kenya warnings prevented loss of life & south africa also hit.
Why was the 2004 boxing day tsunami so destructive?
Earthquake causing it was particularly large
> epicentre close to densely pop coastal communities which has no time to react.
> low lying coastlines meant tsunami could travel several miles inland. No warning system in indian ocean
> many countries lICs so no protection
> in sirlanka cutting of mangroves for tourist development resulted in less buffer.
What was the concequences of the tsunami?
> Costal settlements devastated with 70% of villagers killed. In sumatra, 1500 villages destroyed.
Much infrastructure was destroyed, 60% of the fishing fleet and industrial infrastructure destroyed.
In thailand tourist industry lost US 25 mil and 120,000 jobs for workers lost.
Also caused enviro impacts to mangroves, reefs and wetlands.
Freshwater supplies were contaminated
costing us 10 billion
What was the 2010 Haiti earthquake?
Haiti located between the North american & caribbean plates
> in 2010 mag 7.0 earthqake hit capital
> 3rd deadliest natural disaster ever.
> killed 316,000 people
What were the physical factors for why the Haiti earthquake was so devastating?
> shallow focus (13km)- increasing ground shaking
Liquidification on loose soil caused building foundations to sink
Epicentre 24km from capital- Port-au-Prince- haitis most densely pop city of 2 mil inhabitants
what were the human factors for why the Haiti earthquake was so devastating?
> Poor developing country with limited resources being spent on immediate issues like disease
> High levels of corruption nationally and locally led to a lack of resources and commitment to improving living standards and infrastructure.
> Lack of building control and reg lead to poorly built slum houses in Port au Prince that collapsed under pressure.
> dense urban enviroment heightened the difficulty of aid and rescue.
> Lack of disauster prep meant officials and police didn’t know what to do
> Many haitans living in poverty, so didn’t have resources to prepare or cope with effects of earthquake.
What were the impacts of the 2010 haiti earthquake?
> Much of Haiti’s already poor infrastructure was severely damaged during the earthquake.
> Haiti only had 1 airport, several ports & few main roads, damage prevented aid from being distributed effectively, which increased rescue time and thus, deaths.
> 1/4 of gov officials were killed and key gov buildings were destroyed. So less able to organise recovery and relief.
> Outbreak of cholera due to lack of sanitation and trained medical supplies and workers caused disease to spread so that by 2015 9000+ haitians died and 720,000 affected.
