the focus is the point where the seismic waves originate from whilst the epicentre is the point on the surface directly above the focus
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2
how does the depth of the focus affect the nature of an earthquake
shallow focus earthquakes do more damage because there is not as much of an opportunity for energy to be lost
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3
what type of waves are P and S waves
body wave
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4
what type of wave are P waves in the context of geophysics
longitudinal waves that shake the earth back and forwards
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5
what type of wave are S waves in the context of geophysics
transverse waves that sway the earth from side to side. cannot move through liquids
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6
what type of waves are love and rayliegh waves
surface waves
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7
what type of wave are love waves in the context of geophysics
transverse waves that cause the earth to move side to side
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8
what type of wave are rayleigh waves in the context of geophysics
longitudinal waves that cause the earth to move up and down
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9
do body or surface waves do the most damage
surface
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10
why do S waves do more damage than P waves
buildings cannot withstand horizontal stress which is caused by S waves
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11
distinguish between the earthquakes caused by destructive, constructive, and conservative plate boundaries (3)
destructive plate boundaries have deep focus earthquakes as the oceanic plate is subducted, constructive plates have occasional mild earthquakes, conservative plates have shallow focus earthquakes
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12
why can the construction of dams cause earthquakes
the additional weight of water can put stress on land and reactivate faults
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13
give an example of an earthquake caused by dam building
the hoover dam caused 10000 small earthquakes near lake mead but only 1000 were felt by people
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14
why can fracking cause earthquakes
the pressure caused by injecting fluid can destabilise rocks
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15
give an example of an earthquake caused by fracking
a 4.4 magnitude earthquake in canada in 2014
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16
FINISH TRANSVERSE FAULTS
FINISH TRANSVERSE FAULTS
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17
why are tsunamis caused
underwater earthquakes at subductive plate margins result in the continental plate flicking up and launching water forming a tsunami
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18
why does soil liquefaction occur
loosely packed and waterlogged sediments are disrupted by shaking ground
Studied by 11 people
