Key Terms Flashcards
Seismic
Relating to earthquakes + vibrations of earth + crust
Faults (2)
When rocks of earths crust come under stress
They fracture along cracks called faults
Earthquakes
Tremors that result from release of pressure that builds up crust due to plate movement
Focus (4)
Breaking point of earthquake
Within crust
Shallow - 70km
Deep - 300-700km
Epicentre (3)
Point on surface
Directly above focus
Ground shaking is most intense here
Body waves
Shockwaves that travel through earth
Primary waves (4+)
Body waves
Travel from focus through liquids and solids
Fastest waves
Compressional waves - compress and expand any material move through
Secondary waves (4+)
Surface waves
Cannot travel through solids
Half as fast as P waves
Transverse waves - shake ground at right angles to wave
Surface waves (2)
Travel along earths surface
After body wave s
Love waves (3)
Surface waves
Travel from epicentre
Slowest bust most destructive
Rayleigh waves (3)
Surface waves
Move in rolling motion
Break up the surface
Tsunamis (4)
Giant sea waves
Generated by shallow focus underwater earthquakes
Involve movements of seabed
Travel at speeds of 700km/hr
Liquefaction (2)
Saturated unconsolidated sediments are shaken by shockwaves
Results in objects and buildings sinking into the sediments
Landslide (2)
Type of mass movement
Involves rapid movement of soil and boulders down a slope
Richter scale (3)
Logarithmic 10 point scale
Used to measure magnitude
Above 6 = considered destructive
