seismic waves

Question 1

what is the exact location of the crustal movement called?

Answer 1

the focus

Question 2

what is the epicentre?

Answer 2

the exact location on the surface above the focus

Question 3

what are seismic waves?

Answer 3

vibrations which travel through the earth

Question 4

what are the 3 types of seismic waves?

Answer 4

1. primary
2. secondary
3. L (surface)

Question 5

give 3 features of primary waves

Answer 5

1. the fastest wave
2. longitudinal ( vibrates in direction of travel)
3. can travel through liquid (earths core)

Question 6

give 3 features of secondary waves

Answer 6

1. 1/2 speed of p wave
2. transversal ( vibrates at 90 degrees to direction of travel)
3. cannot travel through liquids, only solids

Question 7

give 2 features of L waves

Answer 7

1. slowest wave of all 3
2. causes most damage as it is the nearest to the surface

Question 8

how do P waves create the shadow zone?

Answer 8

as they refract through the Earths core, the waves exit the core at a different angle, causing a zone without p waves.

Question 9

give 2 features of the richter scale

give a disadvantage

Answer 9

1. logarithmic scale of 1-10
2. measures an earthquakes magnitude

not good for any earthquake over 8 ( cant give clear calculations)

Question 10

give 2 features of the mercalli scale

Answer 10

1. based off of damage not magnitude
2. subjective due to observation

Question 11

give 2 features of the moment magnitude scale

give an advantage

Answer 11

1. logarithmic of 1-10
2. based on the total moment release of the earthquake

can describe very small earthquakes

Question 12

what is liquefaction?

Answer 12

when violently shaken soil with a high water content lose their mechanical strength and starts to behave like a liquid