Earthquakes Around the
When do earthquakes occur?
Why do earthquakes occur?
Where do earthquakes occur?
How do you notice when an
earthquake is occurring?
When Do Earthquakes Occur?
Earthquakes cannot be predicted but
scientists are working on it
Earthquakes happen in both day and
Why Do Earthquakes Occur?
Pieces of the crust of the earth
Vibrations (seismic waves) travel
outward in all directions
Where Do Earthquakes Occur?
Earthquakes happen along fault lines
in the earths crust and on plate
Most occur along the edge of the
oceanic and continental plates
Occur where 2 plates are running
into each other or sliding past each
Major Plates of the World
How Do You Notice When an
Earthquake is Occurring?
Gentle shaking of the ground
Hanging plants swaying or objects
wobbling on shelves
Low rumbling noise
Feel a sharp jolt
Map of Major World Earthquakes
Mexico, 1985 - Facts
Location: Pacific Coast of Mexico,
damage concentrated in Mexico City
Date: September 19, 1985
Time: 7:17 AM
Richter Scale Reading: 8.1
• Aftershock Reading: 7.5
• Two meter high tsunami
Mexico, 1985 - Damage
Number who felt the quake: 20 million
• Fatalities: 10,000
• Injuries: 50,000
• Number of people left homeless: 250,000
800 buildings destroyed – including hotels, hospitals,
Cost to repair damages: $5 billion
Mexico, 1985 – Not the First
In the 20th century, 35 earthquakes
have occurred in this area prior to
1985 with a magnitude greater than
1985 earthquake was not a surprise
• Epicenter located between the states
Michoacan and Guerrero
This area had previously been referred to as
the “Michoacan Gap” but gap was filled by
Mexico, 1985 – Why Here?
West coast of southern Mexico is a
very active seismic zone
Cocos Plate submerges beneath the
North American Plate which causes
earthquakes to occur
The World’s Largest Earthquake
May 22, 1960
Magnitude of 9.5
Over 2,000 people killed
About 3,000 people injured
2,000,000 people homeless
$550 million in damage
Effects on Other Countries
• 61 deaths and $75 million in damage in
• 138 deaths and $50 million in damage
• 32 dead and missing in the Philippines
• $500,000 in damage done to west coast
of United States
The violent eruption of the volcano Puyehue,
which erupted two days after the earthquake,
about 200km from the epicenter .
Pictures of the Catastrophe
Destruction in Valdivia and
1960 Tsunami Destruction at Hilo, Hawaii