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Vocab 14
8th grade Earth science
| Question | Answer |
|---|---|
| Era | unit of time that is divided into periods |
| Period | historical time that can be divided into epochs |
| Geologic time | time scale that divides Earth’s history into units of time. It is a record of the major events and diversity of life forms present in Earth’s history. |
| Qualitative observations | observations that involve the 5 senses and refer to specific properties |
| Quantitative observations | observations that involve numbers, measurement, or relative comparisons |
| Primary (P) waves | the fastest earthquake waves, they travel out from the earthquake focus. They create longitudinal waves. |
| Secondary (S) waves | slow earthquake waves that move out from the earthquake focus.They create transverse waves. |
| Surface waves | earthquake waves that can cause the ground to shake. The form when P and S waves reach the surface of the Earth. |
| Transverse waves | mechanical waves where the particles of mater vibrate by moving back and forth, and perpendicular to the direction the wave travels |
| Longitudinal waves | mechanical waves where the particles of matter vibrate by pushing together and pulling apart, parallel to the direction of the wave. |