Earthquakes and Earthquake Waves

A. Part of the Earth that consists of several large and several small tectonic plates.

B. Movement of a fluid due to temperature difference.

C. Supports the Theory of Plate Tectonics.

D. Pulling the edge of some plates towards the center of the Earth.

E. A theory that states the Earth’s surface consists of large moving plates.

1. Plate Tectonics

2. Gravity

3. Lithosphere

4. Sea Floor Spreading

5. Convection Current

E

D

A

C

B

ReviewReviewPlate TectonicsDeep sea trenchesMid oceanic ridgesSea floor spreading

EarthquakesEarthquakes

A shaking of the earth’s crust due to a release of energyThere are three major earthquake zones:

1. The Ring of Fire1. The Ring of Fire

2. Mid Ocean Ridges2. Mid Ocean Ridges

3. Eurasian – Melanesian Mountain Belt

BoundariesBoundaries

Divergent: Two plates are moving away from each otherSea floor spreading

BoundariesBoundariesConvergent: Two plates are colliding

BoundariesBoundariesSubducting:On plate is forced under another

This is a type of

convergent boundary!

Subduction

zone

Pacific Plate

South America

Andes Mountains

BoundariesBoundariesTransform boundary:Sliding by one anotherNot creating or destroying land

Earthquake WavesEarthquake Waves

P-WavesPrimary Waves- longitudinal waves

P WavesP Waves

Earthquake WavesEarthquake Waves

Arrive first, travel almost twice as fast as S wavesTravel through solids, liquids, gases

Earthquake WavesEarthquake Waves

S-WavesSecondary Waves- transverse waves

Earthquake WavesEarthquake Waves

• Travel through solids only

Surface WavesSurface WavesSometimes called “L”

wavesTravel through solids onlyResponsible for most

damage due to their intense vibrations

Surface WavesSurface WavesSurface

waves occur when P and S waves reach the surface

Location of EarthquakesLocation of Earthquakes

The Focus- the breaking point (inside the Earth) where the vibrations originate

Focus

Location of EarthquakesLocation of Earthquakes

The Epicenter- the location (on the surface) directly above the Focus

Locating EarthquakesLocating Earthquakes

Seismologists can figure out earthquake locations through trilateration

Fresno, CA

Reno, NV

Tonopah, NV

Epicenter

Richter Scale

Richter Scale

http://www.sciencecourseware.com/virtualearthquake/vquakeexecute.

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