what is the exact location of the crustal movement called?
the focus
what is the epicentre?
the exact location on the surface above the focus
what are seismic waves?
vibrations which travel through the earth
what are the 3 types of seismic waves?
- primary
- secondary
- L (surface)
give 3 features of primary waves
- the fastest wave
- longitudinal ( vibrates in direction of travel)
- can travel through liquid (earths core)
give 3 features of secondary waves
- 1/2 speed of p wave
- transversal ( vibrates at 90 degrees to direction of travel)
- cannot travel through liquids, only solids
give 2 features of L waves
- slowest wave of all 3
- causes most damage as it is the nearest to the surface
how do P waves create the shadow zone?
as they refract through the Earths core, the waves exit the core at a different angle, causing a zone without p waves.
give 2 features of the richter scale
give a disadvantage
- logarithmic scale of 1-10
- measures an earthquakes magnitude
not good for any earthquake over 8 ( cant give clear calculations)
give 2 features of the mercalli scale
- based off of damage not magnitude
- subjective due to observation
give 2 features of the moment magnitude scale
give an advantage
- logarithmic of 1-10
- based on the total moment release of the earthquake
can describe very small earthquakes
what is liquefaction?
when violently shaken soil with a high water content lose their mechanical strength and starts to behave like a liquid
