Modern Earth Science Chapter 6 Terms
Terms
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- Earthquakes
- Vibrations of the earths crust.
- Elastic Rebound Theory
- If fault is locked stress builds up until rock factures and then it springs back to the original position.
- Aftershocks
- Small post-earthquake tremors caused by Elastic Rebound
- Focus
- Area along fault where slippage first occurs.
- Epicenter
- Point directly above the focus
- Pacific Ring of Fire
- The largest earthquake zone. Most plates are subducted while others scrape past each other.
- Fault Zones
- Groups of interconnected faults. They form at plate boundaries because of the intense stress caused when plates separate, collide, subduct, or slide past each other.
- P waves
- Primary Waves. Move fastest and move through solids and liquids. Rock part
- S waves
- Secondary Waves. Slower than P waves and can only travel through solids. Rock particles move at right angles to the direction of the waves.
- L Waves
- P waves and S waves turn into L waves or long waves. They are the slowest moving waves. They tavel like ocean waves.
- microquakes
- Earthquakes with a magnitude less than 2.5 on the richter scale.
- Mercalli scale
- Expresses the intensity of tghe quake. Ex. II "Felt only by a few persons at rest, espcially on upper floors of buildings. Delicatly suspended objects may swing"
- Intensity
- The amount of damage a quake causes.
- Tsunami
- Giant ocean waves caused by an ocean floor earthquake.
- Seismic Gaps
- A place where the fault is locked and unable to move. Scientist think that they are places of future earthquakes.