Earthquakes

Kevin Melo.Listening and Speaking V

Vocabulary

Forecast: to estimate how something will be in the future

Fault: A fracture zone in rock along which movement has occurred. 

Magnetometer: An instrument designed to measure the strength and character of Earth's magnetic field. 

Seismograph: an instrument that automatically detects and record the intensity, direction and duration of earthquake and similar events.

Layer: a single thickness of some material covering a surface

Earthquakes are caused by movements of plates underneath the Earth's surface. The places where these plates meet are breaks in the Earth's crust called faults. Earthquakes often happen when these plates along the faults move in different directions

The San Andreas Fault: is a long transform fault in California. Movements along this plate edge have caused huge earthquakes in the cities of San Francisco and Los Angeles

Usually active volcanoes occur near the edges of plates that are moving apart or colliding. Also earthquakes are common in these regions too.

(Ring of fire)

Is Possible Predict Earthquakes?

In 1975, Chinese scientists correctly predicted an earthquake and saved their the lives of many people. But scientists have not yet found sure way of forecasting them

What Instruments Record Earthquakes?

Magnetometerto warn of magnetic

field changes

Seismograph to warn of

underground vibrations

Animals Sense Earthquakes Scientist have noticed that animals

often behave strangely before an earthquake. Horses rear up, dogs bark and snakes come out of holes in the ground.

Seaquake (tsunami) A Seaquake is a

series of large waves of extremely long wavelength and period usually generated by a violent, impulsive undersea disturbance or activity near the coast or in the ocean.

How do earthquakes cause damage?

Earthquakes make buildings sway and wobble until they collapse. The shaking sometimes:

Break gas pipes Causes electrical short-circuits Starting fires

Haiti - January 12, 2010316.000 people lost their livesMagnitude 7.1

Chile - February 27, 2010525 people lost their livesMagnitude 8.8

San Francisco, USA - October 17, 198963 people lost their livesMagnitude 6.9

Tumaco, Colombia - December 12, 1979525 people lost their livesMagnitude: 8.1

Thanks