prediction of seismic activity and it's reduced effects

Question 1

introduction

Answer 1

◍ seismic activity- the vibration earth’s crust caused by moving magma in crust
◍ associated w. earthquakes + volcanoes

Question 2

1. Predicting seismic activity of earthquakes

Answer 2

◍seismologists can’t reliably predict-location of focus impossible
all they can do is identify high risk areas and educate ppl

Question 3

1. prediction of location of earthquake

Answer 3

◍earthquakes linked w. faults(San Andreas S.America): various methods to find location….
◍laser beams-detect plate movement
◍Radon gas-escapes from cracks in crust level of gas is monitored
◍ seismometer-pick up vibrations from crust
◍ level of oil and water in wells (will rise)

Question 4

2. Predicting the seismic activity of volcanoes

Answer 4

◍ volcanologists monitor seismic activity in volcanoes caused by moving magma,bursting gas bubbles and fracturing rocks as volcano changes shape
◍Warning signs:increased co2 emmitions/earthquake activity
◍ warnings given to ppl in high risk zones

Question 5

2. volcano prediction: Networks if seismometers

Answer 5

◍earthquake activity occurs beneath volcano and increases before eruption
◍4-8 seismometers are placed within 20km of vent
◍volcano related earthquakes have a magnitude 3ish occuring 10km beneath volcano

Question 6

2.Volcano prediction:
Ground deformation

Answer 6

◍ground will tilt away from centre of uplift due to rising magma
◍if land subsides bc of magma sinking back to magma chamber- ground will tilt to the centre of subsidence.
◍Electronic tiltmeters record volcano ground tilts
◍Radar images from satellites used to detect ground deformation over land areas->volcano close to erupting the speed of ground deformation increases

Question 7

2.Volcano prediction :Gas analysis

Answer 7

◍rate OF VOLCANIC gases in air is related to volume of magma in magma chamber
◍ measuring changes in emmission rate co2 +sulfer dioxide work out when volcano errupt
◍Automatic chemical sensors send measures by radio by radio to volcano observatories-this meathod predicted mount st. helens 1980 and munt pinatubo

Question 8

reducing the impact of seismic activity

Answer 8

◍Public awareness programmes to educate ppl eg. tokyo
◍roads/building that can withstand earthquakes bu using flexiable materials
◍Earthquake drills held in schools+offices
◍some factories and power stations have their own seismometers.