Impacts of Tectonic Hazards (Edexcel GCSE Geography B)

Case Study: La Palma & Indonesia

• Volcanic eruptions have both primary and secondary effects

• The impact of these depends on a number of factors including:

  • Magnitude of the eruption

  • Location of the eruption

  • Type of eruption

  • Preparation and planning

  • Monitoring and warning

• In developing countries the impacts may be greater due to:

  • Lack of monitoring

  • Less preparation and planning

  • Less warning of impending eruption

  • Lack of economic wealth to pay for technology

Developing - Mount Merapi, Indonesia

• Merapi is a composite volcano with andesitic magma

  • The magma is very thick/viscous and often blocks vents causing pressure to build

  • Leads to explosive eruptions

• It is located on the island of Java on the subduction zone of the Indo-Australian and Eurasian plates

• Three eruptions between 25-26th October 2010 followed by further eruptions until November

• The eruptions were 4 on the Volcanic Explosivity Index (VEI)

Location of Mount Merapi

Primary impacts

• Ash reached altitudes of 18km

• Ash fell up to 30km from the volcano damaging 200 hectares of forest and large areas of crops

• Pyroclastic flow spread 3km 

• A sulphur dioxide cloud formed over Indonesia and the Indian Ocean

• 353 people were killed

 Secondary impacts

• The exclusion zone had to be extended

• Food prices increased due to the destruction of crops and livestock

• Over 300,000 people were displaced

• The airports were closed to flights due to the ash - 2500 flights were cancelled

• People suffered respiratory infections, skin and eye irritations and headaches from the ash and sulphur dioxide

• Tourism fell by 30% (domestic tourists) and 70% (international tourists)

Developed - La Palma

• Part of the Canary Islands, La Palma is located in the Atlantic Ocean off the coast of North Africa

• The Canary Islands are an [popover id="RAr2r~3MbVY7biGB" label=''autonomous region"] of Spain

• There are 33 volcanoes across the Canary Islands, 10 of which are in La Palma

• The Cumbre Viejo volcano on La Palma began to erupt on the 19th September 2021 and the eruption lasted for almost three months

• The eruption was VEI 2 to VEI 3

• La Palma and the other Canary Islands are located on the African plate

• The islands are an archipelago which has formed as the result of a hot spot

• This means that they are not located on a plate boundary but over a magma plume

• A cinder cone volcano with basaltic lava

Primary impacts

• Almost 1,500 houses were destroyed by the lava flow

• Over 1,500 other buildings such as churches, shops, schools were destroyed

• The lava flow cut across the coastal highway and covered 1000 hectares

• Water supply was cut off for almost 3,000 people

• 400 hectares of banana farms were destroyed

• Almost 1,300 hectares of land was effected

• 1 death

Secondary impacts

• Air traffic was suspended on a number of occasions due to ash in the atmosphere

• Over 1000 people were evacuated after the eruption began on the 19th September

• A further 5600 people were evacuated over the next few weeks

• About 20,000 people were exposed to the eruption and its effects

Case Study: Italy & Nepal

• Earthquakes have both primary and secondary effects

• The impact of these depends on a number of factors including:

  • Magnitude of the earthquake

  • Location of the epicentre

  • Population density

  • Preparation and planning

  • Monitoring and warning

• In developing countries the impacts may be greater due to:

  • Lack of monitoring

  • Less preparation and planning

  • Poor building quality 

  • Poor infrastructure

  • Lack of economic funds for technology

Developing - Nepal

• Nepal is one of the poorest countries in the world with a Gross Domestic Product (GDP) of under $1000 

• Located between China and India, Nepal is a landlocked country

• In 2015 80% of the population lived in rural, often remote, communities

• In April 2015 at 11.26 am Nepal was struck by an earthquake, magnitude 7.8

• The epicentre was 80 km northwest of Kathmandu in the Gorka district

• The focus was shallow at only 15 km beneath the surface

• Over 300 aftershocks followed the main earthquake

Primary impacts

• Approximately 9000 deaths 

• Over 20,000 people injured

• Electricity and water supplies cut

• 7000 schools and 1000 health facilities were damaged or destroyed

• UNESCO world heritage sites destroyed as well as many temples

Secondary impacts

• Almost 3.5 million people were made homeless

• Offices, shops and factories were destroyed meaning people were unable to make a living

• Loss of tourist income which Nepal is reliant on

• Damages estimated at between $7 and $10 billion about 35% of the GDP

• Spread of disease due to lack of clean water

• Landslides which blocked roads and rivers

• Avalanches on Mount Everest and in the Langtang Valley

Developed - Italy

• Italy is a High-Income Country (HIC) with a GDP per capita of over $31,000

• It is located in Europe 

• On 24 August 2016 central Italy was struck by a magnitude 6.2 earthquake

• The epicentre was 100 miles to the north-east of Rome

• The focus was shallow at only 5.1km

• Over 200 aftershocks followed the main earthquake over the next couple of days

• Italy is located along the plate boundary where the Africa plate meets the Eurasian plate

• The two fault lines running through Italy are the North-South Fault and the East-West Fault

Primary impacts

• Severe damage to buildings

  • 80% of buildings in Amatrice old town were affected

  • Over 50% of all buildings in Amatrice were damaged and destroyed

  • The school in Amatrice collapsed

• 296 people died

• 400 people were injured

• Farmers were affected as 90% of barns and stalls for livestock in the immediate area were destroyed

• Amatrice hospital was badly damaged

Secondary impacts

• Landslides blocked the roads 

• Psychological effects on the population

• Tourism was negatively affected

• 4454 people were made homeless