earthquakes Flashcards
1
Q
what are earthquakes
A
vibrations caused by earth movement at plate margins and major fault lines
2
Q
how are they formed
A
2 plates trying to pass each other become locked. friction builds up and is released.the vibrations cause an earthquake
3
Q
how are they measured
A
richter-measures energy released-uses a seismometer-scale 1 to 10 and 6 is ten times higher than 5 and one hundred times higher than 4. mercalli-measures damage done-scale 1 to 12
4
Q
christchurch
A
6.3 richter scale. 22nd feb 2011. 30
