Earthquake Locations/Terminology

Elastic Rebound Theory

Seismic Waves

Measuring Earthquakes

I. Seismology: Study of Earthquakes

Faults: Breaks in

Earth’s crust

Near or at the edges

of tectonic plates

Deformation: A change in the shape

of rock due to stress.

Elastic Rebound: Return of deformed

rock to its original shape.

Seismic Waves

P-Waves: Fastest waves, pull & pull, travel through

solid liquids, gases

S-Waves: Second fastest, side to side, travel through

solids

Surface Waves: Slowest waves, very destructive, role

on surface

Richter Scale: Shows magnitude

(energy). A calculation based on

amount of movement recorded on

seismograph.

Modified Mercalli Scale: Quantifies

intensity or damage of Earthquakes.

S waves show mantle core boundary. Why?

Shadow zone shows thickness of outer mantle.

VI. Seismometer: Instrument that records

seismographs (All three seismic waves)

S& P Wave Travel Time vs Distance

Record S and P waves at 3 cities

Subtract P time from S time for each city.

Use S & P Travel Time vs Distance Graph to find Distance to Epicenter for each earthquake