BY-Ahmed Ali707

Ms.Azcona

Earthquakes

What are Earthquakes?

An earthquake is the movement of the ground that occurs when rocks inside earth pass there elastic limit, break suddenly, and experience elastic rebound.

Picture of an Earthquake

Parts of Earthquakes

The surface where they slip is called the fault or fault plane

. The location below the earth’s surface

where the earthquake starts is called the hypocenter,

The location directly above it on the surface of the earth is called the epicenter.

Layers of Earth

What causes Earthquakes?

The plate boundaries are made up of many faults, and most of the earthquakes around the world occur on these faults.

Since the edges of the plates are rough, they get stuck while the rest of the plate keeps moving.

When the plate has moved far enough, the edges unstick on one of the faults and there is an earthquake.

Tsunami

A long high sea wave caused by an earthquake or other disturbance.

Tsunami is a powerful seismic sea wave that begins over an ocean-floor earthquake, and it can reach 30m in height when approaching land, and can cause destruction in coastal areas.

In the open ocean, the speed of tsunami can reach 950 km/h .

Tsunami

How are Earthquakes Predicted?

Scientists can predict where major earthquakes are likely to occur based on the movement of the plates in the Earth and the location of fault zones.

They also can make general guesses about when earthquakes might occur in a certain area, by looking at the history of earthquakes in the region and detecting where pressure is building along fault lines.

Earthquake can be measured by a seismograph, which is an instrument that is used to record a seismic wave all over the world.

ReferencesScience Textbook

Internet websites:http://www.geography-site.co.uk/pages/physical/earth/cause.html

http://earthquake.usgs.gov/learn/kids/eqscience.php