Download Earthquakes

Unit 5: Planet Earth
Topic 5-7 Study Guide
Topic 5: Earthquakes
- Seismologists study earthquakes
- Seismographs are machines attached to the bedrock that
measure earthquake waves (seismic waves)
- A seismogram is the printed report of the waves.
- Richter Scale: a scale from 1-10 that measures the
magnitude of an earthquake
- Aftershocks are mini earthquakes that occur after an
earthquake
- Primary Waves (P Waves): fastest wave, can travel through
solids, liquids, and gases, very little damage (rattling dishes)
- Secondary Waves (S Waves): slower than P Waves, can
ONLY travel through solids
- Surface Waves: strongest (most damage), slowest, rolling
wave
- The farther apart P and S Waves are, the farther away the
earthquake is (like counting between thunder and lightning)
- Epicenter is where the earthquake begins on the surface, the
focus is the place deep in the crust where it begins.
- Normal Fault (tension)
- Reverse Fault (compression)
- Strike-Slip/Transform Faults (Shear)
- Tsunamis (mean harbour wave) is caused by an earthquake
that occurs in the ocean
Topic 6: Volcanoes
- Volcanoes release lava, ash, steam through openings called
vents.
- An inactive volcano is called dormant. An extinct volcano will
never erupt again.
- The Ring of Fire in the Pacific ocean is a belt of active
volcanoes and earthquakes.
- There is volcanic activity in our solar system (Io, Olympus
Mons)
Topic 7: Mountains
- Western Cordillera (mountain range) includes mountains in
Alaska, and the Canadian and American Rockies.
- Mountains form when rock folds or faults (when it is too
brittle to bend)
- Folding: anticline (top), syncline (bottom)
- Faulting: Thrust Faulting (shingles on a roof)
- Complex Mountains (formed by folding and faulting)
- Young Mountains (jagged, high)
- Old Mountains (rounded, low, due to erosion)
- Canada has the Canadian Rockies (AB/BC), and the
Laurentian Mountains (Quebec).
- The Theory of Plate Tectonics is a Unifying Theory
because it explains why earthquakes, volcanoes, tsunamis,
and mountains occur.