Tectonics case studies Flashcards
what was the magnitude of the Haiti 2010 EQ
7.0 magnitude
what was the Haiti EQ caused by
- North american plate slid past Caribbean plate at a conservative plate margin -
- both moving in same direction but one was moving faster than the other
- pressure then built up due to friction pressure was released causing the EQ
what was Haiti’s economy like in 2010 when the EQ hit
GDP per capita- around 350 dollars
between 5-6 million people lived in rural areas - 85% of rural population practised agriculture - 26% of Haiti’s economy
what were the socio- economic impacts of the Haiti EQ
just over 400,000 buildings damaged or destroyed including 4,000 schools and presidents building in port-au-prince
250,000 died
what were some responses to the Haiti EQ
100 million in aid given by USA and 330 million by EU over 800,000 people placed in aid camps. over 100,000 tents and a million plus tarpaulin shelters provided
what were some human reasons for the Haiti EQ
poverty - one of the poorest countries in the world -substandard housing and lack of sanitation - houses poorly structured so easily toppled and people more vulnerable
deforestation - left soil unstable and more likely to cause mudslides and landslides
weak infrastructure - poor access to healthcare, transport and electricty - harder for aid workers to reach people and provide adequate support
political instability - poor governance and corruption made coordinating relief efforts harder- reports of violence and looting after event
what are some physical factors that contributed to the Haiti EQ
location- Haiti is right on the fault zone between the north american and Caribbean plate
Depth - was a relatively shallow EQ - 8-10km below earths surface - more destructive as release more energy closer to surface
mag- high mag so more energy released
what was the VEI of the EFJ eruption in iceland
4
what caused the EFJ eruption in 2010
iceland lies on mid atlantic ridge (constructuve margin) where eurasian plate moves away from north american plate as plates move apart magma rises to surface - active volcanoes
seemingly caused by meeting of one body of magma with another type of magma
what were the socio economic impacts of the EFJ eruption
- no deaths
- 5000 farmers and families had to be evacuated from areas around volcano
- roads around volcano shut down
-local population evacuated safely because of respiratory threats from ash build up
-airspace closed across europe with at least 17,000 flights a day being cancelled - this cost airlines more than 200 million dollars a day - around 2 billion loss overall
-estimated london lost 102 million of tourist income - world bank estimated african countries lost 65 million dollars due to effect of shutdown on perishable exports
what were some environmental impacts of EFJ eruption
Air pollution- released large amounts of ash and sulphur dioxide which is hazardous to humans as well as crops and vegetation
glacial melt- EFJ was under a glacier which caused it to melt and cause floods in nearby areas
soil erosion - ash eroded soil impacting local ecosystems
what were some responses to EFJ that helped reduce impacts
evacuations - icelandic authorities quick to implement evacuation plan for surrounding areas
risk communication - governement provided clear and timely info about eruption and potential impacts - reduced panic and confusion and guide response efforts to where most needed
air traffic management- air traffic was badly disrupted bit management meant organisations could develop new protocols for flying through ash clouds so resumed safely and quickly
scientific monitoring - icelandic meteorological office monitored eruption closely reducing impacts on public health and safety infrastructure and economy
physical factors that contributed to the cause of the EFJ eruption
location - southern iceland - very close to boundary - known for high levels of volcanic activity
magma chamber - magma chamber beneath EFJ when the pressure builds it can cause it to rise to surface
glacier- located under glacier which caused melting and flooding
What was the mag of the Christchurch EQ in 2011
6.3 magnitude
what caused the Christchurch EQ in 2011
Transform / conservative boundary
pacific plate moving south west relative to the australian plate
the fault that ruptured during EQ was previously unknown
what physical factors contributed to the christchurch EQ in 2011
Depth - shallow depth of the earthquakes focus - about 5km deep - stronger shaking and more intense ground acceleration
location of Fault line- city was built on alluvial soils and sedimentary rock - more susceptible to soil liquefaction
Location- New zealand situated on boundary of the pacific and australian plates - high levels of tectonic activity
what human factors contributed to the Christchurch EQ
buildings - many older buildings built before modern building codes so not designed to withstand strong shaking and ground acceleration
land use - buildings built on alluvial soil and sedimentary rock - vulnerable to soil liquefaction
responses to the christchurch earthquake that reduced impacts
emergency response - emergency responders quick to provide aid
evacuation and shelter - ordered evacuation of certain areas of the city and established relief centres for those displaced
international aid
communications- public constantly updated and instructed on how to stay safe
building inspections and demolitions - conducted safety checks of buildings and ordered demolition if deemed unsafe
what were the socio economic impacts of the christchurch earthquake
loss of life and injury - 185 fatalities and thousands of injuries
damage to buildings and infrastructure - estimated loss of billions of dollars
disruption to business and employment - many forced to close or relocate due to damage to premises - impacted local economy and employment levels
housing shortages and displacement - many residents forced to relocate due to damage and risk
psychological impact- many experienced trauma
tourism industry - many visitors had to cancel trips
insurance - many insurance claims and financial losses for people - impacted economic recovery
Environmental impacts of christchurch
soil liquefaction- released sediment into water ways
landslides - more damage to homes and habitats
water contamination - made it difficult to access safe drinking water and impacted aquatic ecosystems
what was the VEI of the pinatubo eruption in 1991
VEI of 6
what did the eruption of mount pinatubo cause
high speed avalanches of hot ash and gas
giant lahars
large cloud of volcanic ash - rose 22 miles into the air
led to acid rain due to due to 22 million tonnes of sulphur dioxide emitted
what was the pinatubo eruption caused by
subduction of the Philippine sea plate beneath the eurasian plate which created a magma chamber beneath mount pinatubo
what were some physical factors that contributed to the pinatubo eruption 1991
volcanic gases - magma chamber was full of sulphur dioxide and other volcanic gases - made eruption more explosive
proximity to magma chamber - was very close
structure of mountain- steep died and at an intersection of multiple faults - more prone to eruption
climate conditions - preceded by heavy rainfall and typhoons - destabilised the volcano
what were some human factors that contributed to the Mount pinatubo eruption
population growth and land use change - led to deforestation, mining and other activities that destabilised the mountain
poor land use practice - improper mining and logging practices - caused soil erosion and sediment build up in rivers which contributed to the lahars
lack of evacuation planning - despite warnings from scientists about possibility of eruption no plan was made - significant loss of life and damage
limited monitoring and communication - not sufficiently to provide accurate and timely info - limited ability of local authorities to response effectively
what were some socio economic impacts of the mount pinatubo eruption
- overall just over 700 deaths
- 75,000 evacuated
- 200,000 homeless
- agricultural land damage - 1.5 billion pesos
- full economy recovery of 10 billion
what were some environmental impacts caused by the mount pinatubo eruption
destruction of forests and habitats
contamination of water sources
air pollution- acid rain and other forms
climate impacts- caused a temporary cooling due to release of large amounts of ash into upper atmosphere
what was the Asian tsunami 2004 caused by
subduction of indio-australian plate under eurasian plate
magnitude 9 EQ
sea floor uplifted and displaced seawater
What were some impacts of the asian tsunami 2004
killed 240,000 plus people in 14 different countries
80,000 houses destroyed
led to dysentery and cholera due to lack of clean water and sanitation in refugee camps- killed estimated 150,000 extra
physical factors that contributed to the 2004 asian tsunami
Earthquake - was one of the most powerful ever recorded - energy released the same as detonation of multiple atomic bombs
depth of EQ- 30km deep - relatively shallow - increased intensity
location of EQ- occurred along convergent plate boundary
coastal topography - many ares were flat and lower lying so experienced greater damage
what were some human factors that contributed to the Asian 2004 tsunami
lack of warning sytems - no effective warning system in place - people caught of guard
poor land use planning - many people were living in areas vulnerable to tsunamis (low lying) due to development
lack of infrastructure - many communities lack roads, bridges and emergency shelters - difficult for aid
lack of preparedness - many communities lacked resources and training to respond effectively
political instability - conflict - e.g. in sri lanka and indonesia where ongoing conflict made coordinating relief harder
responses to the Asian tsunami 2004 that reduced impacts
aid- massive international effort to rescue and provide relief efforts 7 billion dollars by US and IGO’s
reconstruction and rebuilding - years after
creation of warning systems - many countries have now implemented new systems such as sirens text messages
increased disaster preparedness - more training programmes for responders and communities
what caused the 2011 Tohoku tsunami
9 magnitude earthquake uplifted 80 miles off the coast of sendai
convergent margin
what were some impacts of the Tohoku tsunami
nearly 16,000 deaths and thousands missing
300,000 destroyed and future 1 million destroyed
over 200 billion in damages
It hit a nuclear power plant and disabled the power supply - high radioactive releases - contaminated water leaked into pacific ocean and fishing grounds
many displaced
what were some physical factors that contributed to the 2011 Tohoku tsunami
magnitude of the earthquake - 9 on the richter scale - one of largest ever - caused sea floor uplift that displaced a vast amount of water
depth - epicnetre was 70km offshore with depth around 30km - allowed for significant amounts of water displacement
location - off coast from a highly populated and developed area - location of EQ made it easier for waves to reach and affect the coastline
shape of coastline - in some areas the coast funneled the waves into narrow channels amplifying height and power
timing of quake - occurred at 2:46pm local time - middle of workday when many people were in high rise buildings or close to coastline - increased casualties
what were some factors that helped mitigate the effects of the 2011 tohoku tsunami
early warning systems - japan has one of the most advanced tsunami warning systems in the world - wothin minutes a warning had been issued allowing people to evacuate to higher ground
evacuation plans - many coastal towns in japan have well established evacuation plans and designated evacuation routes
building codes - has some of the strictest building codes in the world - many designed to withstand earthquakes and tsunamis
emergency response - have highly trained and well equipped emergency response team
community resilience - japanese communities known for their strong sense of community and cooperation
international aid - lots of financial assistance supplies and medical equipment
