( ( magma ( ( movement and ) ( volcanic explosions ) ) ) . )
(ROOT (NP (NP (NN magma)) (NP (NP (NN movement)) (CC and) (NP (JJ volcanic) (NNS explosions))) (. .)))
magma movement and volcanic explosions.
(ROOT (S (NP (NP (DT The) (NN thickness)) (PP (IN of) (NP (NN magma)))) (VP (VBZ determines) (SBAR (IN whether) (S (NP (DT a) (JJ volcanic) (NN eruption)) (VP (MD will) (VP (VB be) (ADJP (JJ explosive))))) (CC or) (RB not))) (. .)))