EARTHQUAKE VOCABULARY COMPARISON Unit 11 P Wave S

EARTHQUAKE VOCABULARY COMPARISON Unit 11

P Wave & S Wave P Wave Compress and expand in the ground S Wave Vibrate from side to side AND up and down

Seismograph & Seismogram Seismograph A device that record ground movement caused by seismic waves as they move through earth Seismogram The record of an earthquakes seismic waves produce by an seismograph

Stress & Tension Stress A force that acts on rock to change its shape or volume Can be compression, tension or shearing Tension Stress that stretches rock so that it becomes thinner in the middle

Mercalli Scale, Richter Scale and Moment Magnitude Scales Mercalli scale Rates earthquakes according to intensity and how much damage they cause at a particular place. Richter scale Rates earthquakes based on the size of its seismic waves. Moment magnitude scale Rates earthquakes by estimating the total energy related by an earthquake

Focus & Epicenter Focus The point beneath earth’s surface where rock breaks under stress and causes an earthquake Epicenter The point on Earth’s surface directly above an earthquake’s focus

Anticline & Syncline Anticline An upward fold in rock formed by compression Syncline A downward fold in rock formed by compression

Hanging Wall & Foot wall Hanging wall The block of rock that forms the upper half of a fault Hanging wall slopes in Footwall The block of rock that forms the lower half of a fault Footwall slopes out