earthquakes Flashcards
(16 cards)
what is the focus?
the in which the pressure of an earthquake is release
what is the epicentre?
the point of crust immediately above the focus
what are the 3 types of focus?
- shallow (0-70km deep)
- intermediate(70-300km)
- deep(300-700km)
what plate boundary creates the most violent earthquakes?
destructive plate boundarys
how do earthquakes occur at conservative margins?
transform faults have sudden movement, releasing energy
what are 3 human causes of earthquakes?
- building large resevoirs
- deep mining
- fracking
what is the moment magnitude scale?
a logarithmic scale which measures energy released
what is the mercalli scale?
a scale which measures the intensity of damage of an earthquake
what is the richter scale?
a logarithmic scale which measures the total magnitude of an earthquake
what is a logairthmic scale?
a scale where between each number, the value goes up by a different fold
what are the pros and cons of the moment magnitude scale?
- widely understood
- accurate on larger earthquakes
but - inaccurate on small earthquakes
what are the pros and cons of the mercalli scale?
- easy to understand
but - subjective
- varys based off of location
what are the pros and cons of the richter scale?
- commonly understood
- can measure very small earthquakes
but - confusing with the mms scale
- inaccurate on large earthquakes
give 2 primary effects of earthquakes
- ground shaking
- ground rupture
give 3 secondary effects of earthquakes
- soil liquefaction
- tsunamis
- landslides
what is soil liquefaction?
when violently shaken soil with high water conent loses its mechanical strength and behaves like a liquid
