Earthquakes

Krystal RossMrs.. Smith4th hour

April 8, 2011

Basic Background Information

What is an earthquake?• An earthquake is caused by a sudden slip on a fault. The

tectonic plates are always slowly moving, but they get stuck at their edges due to friction. When the stress on the edge overcomes the friction, there is an earthquake that releases energy in waves that travel through the earth's crust and cause the shaking that we feel.

How are earthquakes measured?earthquakes is measured on the Richter scale,

What does magnitude mean?The great size or extent of something

How is magnitude measured?• The Richter scale assigns a magnitude number to an earthquake

based on the maximum amplitude of the seismic waves as recorded on a seismometer and the distance of the seismometer station from the epicenter of the earthquake.

Damage Caused by Earthquakes

Roads

ClimateBuildings

WavesWhat are earthquake waves called?There are several types of earthquake waves including P, or primary,

and S, or secondary, waves,

What two types of seismic waves are there?

Primary wavesSecondary waves

What two types of body waves are there?

Primary (P) and Secondary (S) waves.

BodyBody WavesWaves

How do P waves travel?P waves are primary seismic waves. They are the fastest seismic

waves and they are compression or longitudinal waves, which means the to-and-fro movement of the particles is in the same direction as the wave is traveling. There is an illustration and explanation in the reference below. P waves can propagate through any medium. (solid. liquid or gas)

How do S waves travel? As these waves move, they displace rock particles outward, pushing them

perpendicular to the path of the waves. This results in the first period of rolling associated with earthquakes. Unlike P waves, S waves don't move straight through the earth. They only travel through solid

material, and so are stopped at the liquid layer in the earth's core. Which move faster?S waves

Elastic Rebound

Divergentboundary

The Tohoku EarthquakeThe Tohoku EarthquakeThis quake occurred at :Friday, 11 March 2011 14:46

This quake occurred Eastern Japan

The magnitude of this quake was9.0

Effects on the environment/earth

• Buildings • Bridges • Roads

Effects on the People of Japan

No homes Loss of familyRadiation

Effects on the Economy of Japan

Toyota

Fuji Heavy Industries

Nestlé

GPS Sensors

• One interesting fact about this earthquake is that it moved several GPS sensors. This will require …(Type answer here)

• How does elastic rebound explain this movement?

Type your answer here.

Tsunamis• What is a tsunami?A long high sea wave caused by an earthquake or other

disturbance.• How do tsunami waves appear at sea?Tsunami, also known as seismic sea waves, are caused by

sudden changes in the seafloor, generally earthquakes and more rarely large landslides.

• How high can tsunami waves be?• 30-50 feet tall, sometimes reaching 100-300 hundred

feet tall.• How fast can tsunami waves move?• Tsunami's move from 45 to 60 miles per hour

Websites Usedhttp://www.google.com/images?um=1&hl=en&client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&biw=1269&bih=645&tbm=isch&sa=1&q=What+is+a+tsunami%3F&aq=f&aqi=&aql=&oq

http://www.google.com/search?q=what+effects+on+japans+econmy+after+the+earthquake&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-ahttp://www.audioenglish.net/dictionary/magnitude.htm

http://wiki.answers.com/

http://en.wikipedia.org/wiki/2011_T%C5%8Dhoku_earthquake_and_tsunamihttp://science.howstuffworks.com/nature/natural-disasters/earthquake4.htm