GCSE or A-level geography case study on the Asian tsunami 2004

1. Indian Ocean tsunami 2004
(a secondary impact of an earthquake)
Causes
• The earthquake that caused the tsunami
struck at 7:58am on December 26th 2004
• The earthquake was caused by the
subduction of the Indo-Australian plate
(oceanic) under the Eurasian plate
(continental) 240km off the coast of Indonesia
• This mega-thrust earthquake involved a 20
metre uplift of the sea floor all the way along a
fault line which was over 1000km in length
• The uplift of the sea floor caused a
displacement of billions of tonnes of water
setting in motion a tsunami wave which hit the
coast of Indonesia within half an hour of the
earthquake

2. Indian Ocean tsunami 2004
(a secondary impact of an earthquake)
Impacts of the earthquake Primary effects of the tsunami
• despite being 240km off the coast the • The wave killed people in 14 different
seismic waves from the earthquake still caused countries around the Indian Ocean
damage to poorly built homes and better built totalling over 250,000
structures over 3 storeys high in Banda Aceh (a • The highest death toll was on the
city on the coast of Sumatra) Indonesian island of Sumatra where over
130,000 were killed and over 30,000
remain missing
• In Sumatra over 500,000 people were
made homeless, over 80,000 houses
were destroyed as well as serious
damage to any ports, boats, roads,
bridges, hospitals, forests and crops
within 1km of the shore
• 8 people were killed in South Africa
which is over 8000km from the epicentre
and over 8000 tourists from Australia,
Europe and America were also killed
• In Sri Lanka, a train was derailed by the
force of the wave killing over 1000

3. Indian Ocean tsunami 2004
(a secondary impact of an earthquake)
Secondary effects of the tsunami
• Diseases such as cholera and dysentery
spread due to the lack of clean water and
sanitation in the refugee camps killing an
estimated 150,000
• Incomes were lost due to the destruction of
fishing boats and damage to the ocean bed
• Loss of foreign income from tourism was
significant in Thailand
• Emotional and psychological impacts on the
survivors and aid workers
• Land disputes broke out as documents were
lost in the devastation and in some cases land
was destroyed by erosion from the wave

4. Indian Ocean tsunami 2004
(a secondary impact of an earthquake)
Short term responses
• Bodies were buried in mass graves to help
prevent the spread of diseases
• Over $7billion was provided by governments
and NGOs (charities) in the aid effort and to
help with reconstruction
• Up to 5 million people had to be relocated
into temporary refugee camps and had to be
provided with shelter, food and water
• It took months to simply clear the debris
before rebuilding could start again Long term responses
• The Indonesian government decided to
relocate the people from the refugee camps
straight into new homes. The building of these
new home took a lot longer than expected due
to the lack of building materials and
destruction of main transport routes.
• An tsunami early warning system (shown
below) has now been installed in the Indian
Ocean at a cost of $20 million