Earthquake and Tsunami Case Studies

Question 1

Port-au-Prince, Haiti Earthquake (LIC), 2010: MAIN FACTS

Answer 1

• Haïti Is an inner island of the Caribbean, called the Leeward Islands
• Caused by the North American Plate sliding past the Caribbean Plate at a conservative plate margin.
• January 12 2010
• Magnitude 7 earthquake
• Epiccentre 20km west of Port-au-Prince
• The earthquake struck close to the nation’s capital of 2 million people
• Shallow focus of 13km which caused much damage from shaking, which lasted for nearly a minute

Question 2

Port-au-Prince, Haiti Earthquake (LIC), 2010: IMPACTS

Answer 2

• estimate of 300,000 (316,000) people were killed
• 1.5 million people were made homeless.
• 250,000 residences and 30,000 other buildings destroyed, including the President’s palace
• Transport and communication links were also badly damaged by the earthquake
• The large number of bodies meant that diseases, especially cholera, became a serious problem

Question 3

Port-au-Prince, Haiti Earthquake (LIC), 2010: SEVERITY

Answer 3

• Haiti is the poorest country country in the western hemisphere with a vulnerable population
• The capital has many areas built upon unstable soils and seismic waves amplified within the soil. This caused intense shaking and liquefaction
• The earthquake struck close to the nation’s capital of 2 million people
• many people lived in shacks made of flimsy materials on very steep steep, unstable slopes
• Haiti had no army and few emergency service vehicles or staff to give immediate assistance

Question 4

Port-au-Prince, Haiti Earthquake (LIC), 2010: PREDICTION

Answer 4

• Famous Geologist Paul Mann wrote a report in 2008 that a major earthquake could happen here, and that the damage could be catastrophic.
• Unfortunately, Haïti does not have the resources to heed such warnings.
• The building quality was also proved to be very poor, and most loss of life was due to building collapse.
• Also, because people were so poor they had few ‘reserves’ (money, food) to draw on and there is a very limited social safety net.

Question 5

Port-au-Prince, Haiti Earthquake (LIC), 2010: RECOVERY

Answer 5

• Haiti had poor resilience as recovery largely depended on overseas aid
• 3 years after earthquake, just over half of the debris has been cleared
• 280000 people were still living in camps
• 1/5 of the countries population lost their jobs
• Economic impact expected to be small, less than $US9 billion
• Biggest cost was rebuilding

Question 6

Tohoku Earthquake and Tsunami (HIC), 2011: MAIN FACTS

Answer 6

• occured on 11 March 2011
• most powerful earthquake to hit Japan
• one of the 5 most powerful earthquakes in the world
• Earthquake (9.0 magnitude) was recorded in East Asia, in the Pacific Ocean.
• earthquake occurred where the Pacific Plate is subducting under the Okhotsk plate, which carries North Japan (destructive plate boundary)
• Recorded near the east coast of Honshu, Japan
• Focus depth of only 32km
• tsunami was created by the earthquake
• a huge wave (14 m) created hit the coast of Honshu and flooded Japan

Question 7

Tohoku Earthquake and Tsunami (HIC), 2011: IMPACTS

Answer 7

• 200000 people killed
• 500km squared of coastal plains were hit, destroying farmland, settlements and communications
• Ruptured gas pipes which led to fires
• fewer than 5% of the damage came from the earthquake
• Tsunami damaged the Fukushima Nuclear Power Plant, disabling the emergency generators needed to cool reactors and leading to nuclear meltdowns and radiation leaks
• The tsunami defenses in the area were built to cope with an 8.0 magnitude earthquake, not a 9.0
• Japan wasn’t prepared for a 1000-year occurence tsunami

Question 8

Tohoku Earthquake and Tsunami (HIC), 2011: PREDICTION AND WARNINGS

Answer 8

• While Japan has in place a high-tech warning system to alert the public when an earthquake is happening, it didn’t work as well as it might have in 2011
• The warning was issued just 8 seconds after the first wave of the earthquake was detected. It sent a message to 124 television stations and 52 million phones. It caused bullet trains to stop and elevators to halt
• calculations of the earthquake’s likely strength based on the initial wave turned out to be wrong because the earthquake increased in power over time.
• the system underestimated the severity and extent of the quake, and the warning was not sent to places like Tokyo
• The tsunami warning did not reach many coastal residents who had already evacuated, or whose TVs and radios stopped working due to power outages sparked
• Despite the fact that the tsunami hit 30 to 60 minutes later, man people had no warning of this
• In the future, better alert systems are needed to send out updated information to the public before and during an emergency

Question 9

Tohoku Earthquake and Tsunami (HIC), 2011: MITIGATION

Answer 9

• Constructing sea walls along low-lying stretches of coast and breakwaters at entrances of bays and harbours
• planting belts of trees between the shoreline and the areas requiring protection
• where development exists, establish adequate warning and evacuation systems
• set standards of construction for structures within harbours and known run-up areas
• development of coastal forests - may stop driftwood, reduces water flow velocity, provides a life-saving trap for people swept off land by a tsunami run-down, creates sand dunes which serve as natural barriers