Tectonics Case Studies

Volcano Case Study

Eyjafallajokull 2010

Volcano erupted under a glacier

• Cause local flooding due to sudden ice melt

• Local water supplies contaminated

• 100,00 commercial flights cancelled due to ash clouds

• European economy lost $5billion

• No deaths

Volcano Case Study

Montserrat 1995

Part of an island arc in the Caribbean sea (formed where the Atlantic plate sinks beneath the Caribbean plate)

• Only 16km long and 10km wide, consisting almost entirely of volcanic rock

• Volcano had been dormant for 350 years

• Was a thriving tourist destination with a population of 11,000

• July 1995 the Soufriere volcano in the south of the island began to erupt huge clouds of ash

• Over the next 5 years, these eruptions continued, with pyroclastic flows also affecting a large part of the island

Effects

• 19 dead

• 7000 moved (population dropped 4000)

• Plymouth (capital) destroyed

• 2/3 housing destroyed

• 3/4 infrastructure destroyed

• Lots of farmland destroyed or abandoned

• Acid rain damaged plants

• Top heavy population pyramid - young people no longer saw a future on the island

Governance in a developed country

Japan 2011

Mega-disaster, unusually high impacts

Hazard

• 9.0 magnitude earthquake

• 4.5 magnitude aftershocks

• Shallow focus - 20 miles

• Tsunami reaching heights of 40m

Vulnerability

• Landslides

• High population density

• Coastal

• Strong infrastructure

• Low level corruption

Capacity to cope

• Sea walls

• Strong healthcare

• Rescue teams

• Earthquake and tsunami drills

• Strong economy

• Strongly enforced building regulations - 75% built with earthquakes in mind

• 110,000 defense troops mobilised within 24 hours

Short term impacts

• 15,000 + deaths

• 6,000 + injured

• 130,000 displaced

• Fukushima nuclear meltdown

• Immediately after the earthquake, all radio and TV stations switched to official earthquake coverage, advising people

Long term impacts

• Economic cost of $235billion

• Nuclear meltdown

• Roads and railways destroyed

• 1000 buildings destroyed from liquefaction

• The Bank of Japan offered $183billion to Japanese banks to keep them operating (protecting the economy)

Governance in a developing country

Haiti 2010

Hazard

• 7.0 magnitude earthquake

• Shallow focus - 8.1 miles

• Epicentre 16 miles from Port-au-Prince (capital)

Capacity to cope

• Corrupt governement - a lot of money donated was never seen

• 80% population live below povery line

• Unregulated building codes

• Heavily indebted to US, German and French banks

• Small airport - struggled to recieve aid

Short term impacts

• 200,000 + dead

• 300,000 + injured

• 1.5million displaced

• 4000 schools destroyed

Long term impacts

• Cholera outbreak killed 9000 by 2015

• $1.1billion raised between major charities

• World bank waived debt repayments for 5 years

Never fully recovered (Parks Hazard Response Curve)

Pressure and release model

Haiti 2010

Root causes

• heavily indebted to US, German and French banks

• Corrupt government

• 80% population live below poverty line

Dynamic pressures

• Poor management systems

• Poor education systems

• Lack of urban planning and building regulations

• Rapid urbanisation leading to slums

• Significant deforestation and soil degredation

• High population density

Unsafe conditions

• Soft soil amplified seismic waves

• Low GDP per capita $1300

• Cheap / poorly built buildings

Hazard

• 7.0 magnitude earthquake

• Triggered a small tsunami

Nepal 2015

Hazard

• 7.9 magnitude earthquake

• Shallow focus - 9.3 miles

• 48 miles northwest of Kathmandu

• Difficult resuce efforts due to topography

Capacity to cope

• 40% families live below poverty line

• 90% depend on subsistence farming (growing crops sufficient only for one's own use)

Short term impacts

• 8000 + dead

• 19000 + injured

• 3million displaced

• Triggered avalanches and landslides - destroying Langtang village

• 19 dead from landslide on Everest

Seismic waves

P-waves (primary)

• Fastest

• Arrive first and cause least damage

S-waves (secondary)

• Arrive next and shake the ground violently, causing damage

Love waves

• Arrive last as they only travel across the surface

• Large amplitude and cause significant damage, including fracturing the ground surface

Risk equation

Risk =

(Hazard x Vulnerability) / Capacity to cope

Hazard Management Cycle

Preparedness

• Community education

• Resillient building

• Prediction

• Warning

• Evacuation technology

Response

• Immediate help

• Emergency shelter

• Food and water

Recovery

• Rebuilding infrastructure and services

• Rehabilitating injured people and their lives

Mitigation

• Acting to redue the scale of the next disaster

• Land-use zoning

• Hazard-resistant buildings and infrastructure