Hazards: Earthquakes

By Alexei John Acacio

What is an Earthquake?

• An earthquake is a sudden shaking of the earth’s crust.

• There are a few million that occur every year; however, only 150 will cause significant damage.

• Earthquakes are measured in magnitudes on the Richter Scale. The higher the magnitude, the greater the intensity of the earthquake is.

What causes Earthquakes?

• Plate Margins• Moving of plate margins can cause earthquakes.

– Happens in all types of plate margins: most common in conservative and convergent boundaries.

• Volcanic• Volcanic Eruptions can cause the ground to shake due

to the energy it releases. This causes earthquakes.

What places are at risk?This map shows places in the world where earthquakes are most

likely to occur.

Why are Earthquakes a Hazard?

• Earthquakes cause damage to:•Humans•Structures•Economies

How do Earthquakes affect humans?

• Earthquakes destroy buildings and other structures•Humans may get injured or die. •There will be damage to cities.•Earthquakes disrupt important utilities such as water and electricity.

Case Study: 2010 Haiti Earthquake

• Haiti sits on a fault line between the North American and Caribbean Plate.

• This has led to Haiti being prone to major Earthquakes.

• On January 12, 2010 a major earthquake struck Haiti, killing 250,000.

• To this day, Haiti is still suffering the effects.• 1.2 million Haitians are still living in tents, despite the

earthquake happening nearly a year ago. • Infrastructure has yet to be rebuilt.

How do Earthquakes affect economies?

• Earthquakes disrupt trade and causes billions of dollars in structural damage. • E.g. Haiti has yet to recover from the

recent 2010 Earthquake. The economy has suffered extremely due to loss of important infrastructure.

How do Earthquakes damage structures?

• The foundations of buildings and other structures are weakened or destroyed by Earthquakes. • This may cause them to collapse, or be

declared unfit for human occupancy. » Hundreds of buildings in Haiti

collapsed.

How do we prepare for Earthquakes?

• Countries employ building codes• These require structures to be able to withstand major Earthquakes.

– In Haiti’s case, the code was not properly enforced.

• Earthquake warning systems• These predict earthquakes, and tells the public to prepare.

• Preparedness– Things individuals can do to help them survive in the event of an

earthquake• Make sure there are no heavy objects that can fall.• Know emergency numbers• Ensure that your house will not collapse in the event of an earthquake.

Make an engineer check your house’s foundation regularly.

What do we do during earthquakes?

• Hide under furniture to ensure that objects don’t fall directly on you.

• Immediately vacate the building upon the conclusion of the tremor. The building may not withstand aftershocks.

• Turn off electrical appliances to prevent a fire.

What happens after Earthquakes?

• Emergency services may not be able to respond immediately. Instead international help may arrive.

• E.g. Haiti’s emergency service system was not able to cope with the disaster. The United Nations and other countries sent humanitarian workers to help the victims.

And some final thoughts…

•Earthquakes are not man caused. The best way to prevent the negative effects is to be PREPARED.

Bibliography

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Earthquake Early Warning from Seismic Warning Systems - Home. Web. 03 Dec. 2010. <http://www.seismicwarning.com/>.

"Haiti Still Suffering Six Months on from Earthquake - Telegraph." Telegraph Online. 09 July 2010. Web. 03 Dec. 2010.

Polyné, Millery. "Haiti earthquake of 2010." World Book Student. World Book, 2010. Web. 2 Dec. 2010.

"The Psychology of Suffering: How We Cope With Cosmic Evil | Psychology Today." Psychology Today: Health, Help, Happiness Find a Therapist. Web. 03 Dec. 2010. <http://www.psychologytoday.com/blog/evil-deeds/201001/the-psychology-suffering-how-we-cope-cosmic-evil>.

Stock, Joann. "Earthquake." World Book Student. World Book, 2010. Web. 1 Dec. 2010.

"What Causes an Earthquake?" The Geography Site. Web. 02 Dec. 2010. <http://www.geography-site.co.uk/pages/physical/earth/cause.html>.