Where do earthquakes occur?

Plate Tectonics

The Ring of Fire

EarthquakesWhat instrument do we

use to measure earthquakes? What do the values

mean?

What scale do we use to report the magnitude of an

earthquake?

Magnitude Average Annually

8 and higher 1 ¹

7 - 7.9 17 ²

6 - 6.9 134 ²

5 - 5.9 1319 ²

4 - 4.9 13,000

(estimated)

3 - 3.9 130,000

(estimated)

2 - 2.9 1,300,000

(estimated)

¹ Based on observations since 1900. ² Based on observations since 1990.

Earthquakes

How many Earthquakes (on average) occur on the Earth each

year?

RecentEarthquake in Haiti

• January 12th 2010, Magnitude 7.0 on the Richter Scale!!

•Lot’s of BIG (<6.0) ‘aftershocks’

• Occurred 15 km below the surface of the Earth (why there?)

Recent Earthquake in Haiti

What type of fault?

Recent Earthquake in Haiti

230,000 Confirmed Deaths…

(6th deadliest earthquake)

Recent

Earthquakes in Chile• February 27th 2010, Magnitude 8.8 on the Richter Scale!!

•Lot’s of BIG (<6.5) ‘aftershocks’

• Occurred 35 km below the surface of the Earth (why so deep?)

• ~500 people died

SubductionWhere do we get earthquakes?Where do we get volcanoes?

CHILE

volcanoes

Where do we get earthquakes?Where do we get volcanoes?

Focus

Epicenter

Hait vs. Chile Discussion

What are the main differences between the

Haiti and Chile Earthquakes?

Haiti

Chile

Where was the LARGEST recorded Earthquake in the WORLD?

Earthquakes

• May 22nd, 1960 in CHILE!!! Magnitude 9.5Magnitude 9.5 on the Richter Scale!

EarthquakesThe Earthquake in 1960 in CHILE was SO BIG that it

is thought to have caused a volcano to erupt!!

Cordon Calle volcano with an eruption cloud. The volcano, which was within 200 km (~124 miles)

of the earthquake epicenter, began to erupt two days after the earthquake.