1. 3 PHYSICAL PROCESSES AND TECTONIC HAZARDS

Question 1

What is an earthquake?

Answer 1

-shaking of ground caused by sudden motions along faults

Question 2

what is a fault?

Answer 2

-fracture in rocks that make up earths crust

Question 3

what is the epicentre?

Answer 3

-point at surface of earth directly above hypocentre

Question 4

hypocentre?

Answer 4

-point within earth where an earthquake rupture starts

Question 5

what are plates?

Answer 5

-massive slabs that make up outer layer of earths surface
-movements along faults trigger earthquakes

Question 6

what are seismic waves?

Answer 6

-waves that transmit the energy release by an earthquake

Question 7

what are primary waves?

Answer 7

-vibrations caused by compressions
-spread quickly from fault at rate of 8km/s
-can travel through solids liquids and gases
-least destructive
-very fast

Question 8

what are secondary waves?

Answer 8

-move slower
-vibrate at right angles to direction of travel
-only travel through solids

Question 9

what are love waves?

Answer 9

-surface waves with vibration occurring in horizontal plain
-high ampllitude

Question 10

what measures seismic waves?

Answer 10

-seisometer
-measures amount of ground shaking during earthquake

Question 11

what is soil liquefaction?

Answer 11

-cause buildings to tilt and collapse
-tilt up to 60 degrees like in japan
-land adjacent to rivers can present hazard by sliding under low friction conditions across a liquefied soil area known as lateral spreading
-creating large fissures in ground surface
-damage to roads and bridges

Question 12

landslides?

Answer 12

-secondary hazard
-slopes weaken and fail
-as many destructive earthquakes occur in mountainous areas
-landslides can travel several miles
-growing in size
-picking up trees, boulders, cars