Earthquakes quiz

More questions about Earthquakes

These visible examples show the question style. LearnClash turns the full topic into ranked duels and spaced repetition.

1. 1 Easy

   What is a crack in rock whose two sides have slipped called?

   Answer: Fault

   Why: A crack where the rock has not moved at all is a joint; it only becomes a fault once the two sides slide past each other.

2. 2 Medium

   Which US state has the most earthquakes?

   Answer: Alaska

   Why: Since 1900, Alaska has averaged about one magnitude 7 quake every year.

3. 3 Hard

   What dated the 1700 Cascadia quake to the exact day?

   Answer: Japanese records

   Why: No shaking was felt in Japan when the waves came ashore, so local records describe a mystery wave now called an orphan tsunami.

4. 4 Easy

   What is the surface point right above a quake's start called?

   Answer: Epicenter

   Why: The quake itself begins underground at the hypocenter, or focus; the epicenter only marks the spot on the surface straight above it.

5. 5 Medium

   Why has the number of recorded quakes risen since 1900?

   Answer: More seismometers

   Why: Reporting seismic stations grew from about 350 to over 4,000 in 70 years, so far more small quakes now get caught.

6. 6 Hard

   Why can't S waves pass through Earth's outer core?

   Answer: Liquid

   Why: Blocked by the liquid core, direct S waves vanish beyond about 103° from a quake, leaving a gap called the S-wave shadow zone.