tectonics earthquake case studies

Indian Ocean Tsunami, 26 Dec 2004,

Tsunami

case study for - Secondary hazards - Sea floor was pushed upwards displacing a huge vol of water and creating devastating tsunami waves

Global impacts - smaller islands in Indian Ocean destroyed, tourist hotels in Thailand destroyed

indian ocean tsunami details

Converging Destructive : Indo-Australian subducting beneath Eurasian plate.

causes: EQ epicenter was under the Indian ocean.

Magnitude 9 on Richter scale

impacts: Smaller islands in Indian Ocean destroyed

Coastal buildings destroyed

Fishing villages destroyed

Lines of communication, electricity power lines all cut off.

250,000 died

Cholera outbreak

Tohoku, Japan, 2011

Case study for: EQ centered on sea floor, triggered a 39m high tsunami. Also caused major nuclear disaster at power station.

Good responses

Good governance

Good preparedness - sea walls in place but not high enough

Boundary: Converging destructive - Pacific plate subducting beneath North American plate.

tohoku details

causes : EQ occurred off the coast of Honshu, Japan's main island. 9.0 magnitude. Triggered a 39m high tsunami. 3rd biggest EQ in last 100 years. Wave went 10km inland.

impacts: 20,000 died/went missing

120,000 buildings destroyed

150,000 residents had to be evacuated as a result of Fukushima nuclear accident

NE coast of Japan moved East by up to 4m.

Responses: All nuclear power stations shut.                                      

Tsunami warnings 3mins after initial shock.               

Established a coastal protection policy.            

Sea walls raised from 5m tall to 15m. Project cost about 8.6bn USD.

nepal eq, 2015

landslides

case study for - Secondary hazard - landslides in Langtang Valley, avalanches on Mt. Everest killed 20. (geographical factors)

Bad governance

Bad preparedness

Collision

nepal eq details

causes - 7.8 magnitude EQ

Building standards ignored

Area only had 12 fire engines.

High population density

Rainy season made it hard to send in aid

Corrupt gov so int aid went to NGOs which struggle to coordinate responses

Rainy season so satellites had poor visibility

impacts - 300 aftershocks

Killed 9000+ people (1/3 of total pop)

Whole region shifted 3m

7,000 schools flattened

26 hospitals destroyed

christchurch, new zealand, 2011

liquefaction

case study for - Secondary hazard - liquefaction

Geographical location

Preparedness as previous EQs meant education and awareness and EQ proof buildings

Good responses

Good governance

Transform - Pacific plate and Australian plate sliding past each other

christchurch details

causes - Coastal city = high water table making more prone to liquefaction.

Slap down effect amplified magnitude (7.3) of EQ (unconsolidated rock goes down due to gravity & denser stuff going up)

Happened at midday so many outside

impacts - 1/5 of population left Christchurch permanently

100,000 buildings had to be demolished

185 deaths

Liquefaction damaged 100,000 buildings

Buildings flooded

Economic cost of 28bn USD

80% of water supply and sewerage systems damaged

responses - ST - 30,000 people had toilets put in                             

LT - task force created, people educated on risk, zoning maps made to where damage is and places that need rebuilding. EQ Recovery Authority created to organize rebuilding of region.     

Amatrice, Italy, 2016

Ground shaking

case study for - Primary hazard - ground shaking (6.2 magnitude)

Poor governance

Time of day

causes - Old buildings weren't retrofitted to withstand EQ despite gov knowing area is seismic so an event is likely.

3:32 AM

amatrice details

impacts - Two hundred ninety-nine people died, 400 were injured, and 4454 were homeless.

• 293 historic buildings were damaged or destroyed, including the Basilica of San Francesco in Amatrice

responses - Ten thousand homeless people were accommodated in 58 tent camps.

• Sports halls were converted to provide shelter, and hotels on the Adriatic coasts were used to home people temporarily.

turkey-syria, 2023

case study - primary hazard, Regional impacts (affected both Turkey and Syria) Felt in Leb and Cyprus

Seismic Gap Theory as East Anatolian Fault is an active fault

Poor governance

Vulnerable population

Time of year

Poor responses

Poor preparedness

Conservative plate boundary

turkey syria details

causes - Occurred at 4:17a.m.

Corruption in both countries

Rebel groups in control of areas of Syria

1.7m refugees living in shelters in Turkey

February so harsh winter conditions

Building owners given certificates saying buildings were safe as long as they paid.

Hazard map - rare, sudden onset, lasted 75-90 sec,7.8 mag, regional extent, 4:17A.M

 impacts - Pancaking effect due to poor buildings - 20,000 destroyed

50k deaths in Turkey mostly refugees

8,000 deaths in Syria

Landslides then occurred

Haiti, 2010

primary hazard - ground shaking

case study for - Poor governance

Local impacts

Bad response

Social (poverty)

Not prepared

Magnitude 7

Transform boundary

Caribbean and North American plate

haiti details

causes - Buildings not aseismic

Many living in shanty towns on weak, steep slopes

Very poor community

Happened 25km west of capital Port-Au-Prince

Previous Eqs but government had other priorities so didn’t prepare

 impacts - $13bn worth of damages

1/4 of a million buildings were damaged leading to 200,000 deaths

4,000 schools collapsed

Hospitals, roads, port and airport damaged

Extra 10,000 people died from cholera outbreak.

responses - POOR RESPONSES : Aid couldn’t enter as port, roads and airport damaged.                          

US govt invested aid into US companies to complete projects in Haiti as the Haiti gov is corrupt but these projects were long term and never completed. By 2nd anniversary of event many still in makeshift tents waiting to be housed.