Geography of Western Canada

Earthquakes: Getting Ready For The Big One

What is an Earthquake?

• An earthquake is a sudden, sometimes violent, shaking of the ground caused by the sudden release of stored energy within the Earth’s crust

• Earthquakes are natural events, like snowstorms or tornadoes

• Part of an ongoing geologic process that shapes the surface of our planet

What is an Earthquake?

• Earth’s surface sits upon seven large, and several smaller, crustal plates that are constantly in motion over the planet’s molten core

• There is continuous force within and between each of these plates

• When the rock can no longer withstand this stress they suddenly break or slide creating an earthquake

Seven major crustal plates and several minor plates

80% of all earthquakes occur in the circum-Pacific belt

Seismic Activity

• The west coast of BC is the most active seismic area in Canada

• 300 small quakes occur along the Juan de Fuca subduction zone every year

Seismic Activity

How are quakes measured?

• The Richter scale measures the amount of energy released at the hypocentre

• Each step on the scale is ten times greater than the previous one

Earthquake Vocabulary

• Seismic: having to do with earthquakes

• Subduction zone: long region with a trench through which a descending tectonic plate is assimilated into the earth’s surface

• Epicenter: the Earth’s surface directly above the quake

• Richter scale: a measure of the power of earthquakes

Disaster Planning

• Working in groups of four, imagine how you would respond to an earthquake here in Vancouver

• Outline the potential dangers and hazards in your community

• Develop a list of the provisions and equipment you would need in the event of an earthquake

• Make a poster with your group’s ideas, be creative