Tectonics tsunami case studies Flashcards
Developing example
Indian Ocean
Emerging example
Talcahuano (Chile)
Developed example
Japan (same as earthquake)
Developing date and time + mag
26th December 2004 (Boxing Day), 07:58
9.1
Emerging date and time + mag
27th February 2010, 03:34
8.8
Developed date and time + mag
11th March 2011, 14:26
9.1 (from 9.0)
Cause of developing tsunami + focal depth
Megathrust at subduction zone caused 20m uplift (I-A under Eurasian)
30km
Cause of emerging tsunami + focal depth
Megathrust at subduction zone (Nazca under SA)Cause of developing tsunami
35km
Cause of developed tsunami + focal depth
Megathrust at subduction zone (Pacific under NA)
30km
Features of developing tsunami
24m height
up to 800km/h speeds
inundated 3km inland
Features of emerging tsunami
2.6m height
725km/h
Features of developed tsunami
up to 10m height
inundated 10km inland
800km/h
Indian Ocean social impacts
Fatalities in 14 countries
Over 200,000 deaths (tourism played a role)
1.7m homeless
Passenger train in Sri Lanka derailed- killed 1700 people (largest rail disaster in terms of life lost)
Indian Ocean economic impacts
$15b in losses
60% Sri Lanka’s fishing industry destroyed as ports lost
Indian Ocean environmental impacts
8m litres of oil escaped in Indonesia -> damaged coral reefs + coastal wetlands
crops + farming land destroyed
Salt water damaged freshwater ecosystems
Talcahuano social impacts
525 deaths
370,000 homes destroyed
Supply shortages led to widespread looting in Concepción
Talcahuano economic impacts
$15-30b losses
Insurance companies lost up to $8b
Ports destroyed
Power outages meant copper production halted for a day
Food prices tripled in some places
Talcahuano environmental impacts
debris from buildings
Pipe damage meant unprocessed sewage released into Biobio river
Japan social impacts
Over 15,000 deaths
122,000 homes destroyed
130,927 homeless
4000 roads destroyed
Japan economic impacts
$240b losses
Power cuts so lack of business activity
46,000 buildings destroyed
Japan environmental impacts
Radioactive chemicals leaked + found in Tokyo’s drinking water
5m tonnes debris in sea
Cracked a major iceberg in Antarctica
Why was Indian Ocean vulnerable?
One of most powerful earthquakes recorded- felt in India
Mostly developing countries
Densely populated region
Coastlines low lying
Occurred during main tourist season
No warning system (except Thailand, but failed to function adequately)
Loss of mangroves e.g. due to prawn aquaculture
Why was Talcahuano vulnerable?
Reaction of warning system not fast enough
Disproportionately killed tourists camping in low lying areas- locals evacuated to higher ground
Daylong blackout followed
Epicentre only 70 miles from urban area
Why was Japan vulnerable
Very powerful earthquake
Particularly shallow offshore area = increased shoaling so taller wave
Islands diffracted waves, so took longer to reach other land masses = reduced impact there
Lowlands located on east coast
BUT had warning 3 minutes after earthquake = 20 mins to get to higher ground
Why was Boxing Day tsunami considered mega-disaster?
14 countries impacted
required international aid
Large economic losses and deaths across countries
Why was Japan tsunami considered mega-disaster?
Economic impacts had global consequences e.g. car supply chain disruptions
Loss of public acceptability of nuclear power-> countries e.g. Germany either shut down power plants or abandoned plans to build new ones
Changes after Indian ocean tsunami
late 2006- DART system to detect future tsunamis (only 6 buoys in South Pacific prior to tsunami), now 60
