( ( ( ( ( ( Although ( rising ( from ( ( ( much greater ) depths ) ( than ( other magmas ) ) ) ) ) ) ( , ( ( these ( pipes ( and ( volcanic cones ) ) ) ) ( are ( relatively ( ( small and ) rare ) ) ) ) ) ) , ) but ) ( they ( erupt ( in ( extraordinary ( supersonic explosions ) ) ) ) ) ) . )
(ROOT (S (S (SBAR (IN Although) (S (VP (VBG rising) (PP (IN from) (NP (NP (ADJP (RB much) (JJR greater)) (NNS depths)) (PP (IN than) (NP (JJ other) (NNS magmas)))))))) (, ,) (NP (DT these) (NNS pipes) (CC and) (NN volcanic) (NNS cones)) (VP (VBP are) (ADJP (RB relatively) (JJ small) (CC and) (JJ rare)))) (, ,) (CC but) (S (NP (PRP they)) (VP (VB erupt) (PP (IN in) (NP (JJ extraordinary) (JJ supersonic) (NNS explosions))))) (. .)))
Although rising from much greater depths than other magmas, these pipes and volcanic cones are relatively small and rare, but they erupt in extraordinary supersonic 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))) (. .)))