( ( ( The majority ) ( of earthquakes ) ) ( worldwide ( ( ( ( ( occur ( at ( plate boundaries ) ) ) ( when ( plates stick ) ) ) and ) ( then ( jump ( past ( each other ) ) ) ) ) . ) ) )
(ROOT (S (NP (NP (DT The) (NN majority)) (PP (IN of) (NP (NNS earthquakes)))) (ADVP (RB worldwide)) (VP (VP (VB occur) (PP (IN at) (NP (NN plate) (NNS boundaries))) (SBAR (WHADVP (WRB when)) (S (NP (NNS plates)) (VP (VBP stick))))) (CC and) (VP (ADVP (RB then)) (VB jump) (PP (IN past) (NP (DT each) (JJ other))))) (. .)))
The majority of earthquakes worldwide occur at plate boundaries when plates stick and then jump past each other.
(ROOT (S (NP (NP (DT The) (JJ vast) (NN majority)) (PP (IN of) (NP (NN earthquake)))) (VP (VBZ occurs) (PRT (RP along)) (NP (NP (CD one)) (PP (IN of) (NP (NP (CD three) (NNS types)) (PP (IN of) (NP (NN plate) (NNS boundaries))))))) (. .)))