Investigation 2 Facts The Interior of the Earth
Jan 03, 2016
Point of originsFocus
The point inside Earth where a seismic wave begins.
EpicenterThe point of the
Earth surface directly above the focus.
Measuring MagnitudeRichter Scale
Charles Richter developed a scale that uses the size of waves to determine the magnitude of an earthquake.
Types of Seismic Waves Body Waves
Compressional Wave (P-Wave) Primary
Shear Wave (S-Wave) Secondary
Surface WavesRayleigh Wave
named for John William Strutt, Lord Rayleigh. He mathematically predicted this kind of wave in 1885 Love Wave
named after A.E.H. Love, a British mathematician who discovered it in 1911.
Investigation 2 VocabularySeismographShadow zonePhysical modelConceptual modelMathematical modelNumerical Model
Average wave speedCompressional wave (p-wave)Shear wave (s-wave)Seismic waveBoundaryRefractionRichter scaleMagnitude
Body WavesCompressional
WaveEnergy is compressed or squeezed together then released in a straight pathway.
Able to flow through solids, liquids, and gases
Shear WaveThe second wave you feel in an earthquake.
An S wave is slower than a P wave and can only move through solid rock.
Surface WavesRayleigh WaveA Rayleigh wave rolls along the ground just like a wave rolls across a lake or an ocean. Because it rolls, it moves the ground up and down, and side-to-side in the same direction that the wave is moving.
Love WaveIt's the fastest surface wave and moves the ground from side-to-side.
http://www.geo.mtu.edu/UPSeis/waves.html
RefractionWave refraction: When a set of waves cross a boundary (change of material in the Earth’s surface) causing it to change speed and direction.
Average Wave SpeedThe average speed a wave travels in a matter of seconds.Ave. wave speed= distance (cm)
time (s)