( ( Submarine eruptions ) ( ( may ( produce ( seamounts ( which ( may ( break ( the ( surface ( to ( form ( volcanic ( islands ( and ( island chains ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Submarine) (NNS eruptions)) (VP (MD may) (VP (VB produce) (NP (NP (NNS seamounts)) (SBAR (WHNP (WDT which)) (S (VP (MD may) (VP (VB break) (NP (DT the) (NN surface) (S (VP (TO to) (VP (VB form) (NP (JJ volcanic) (NNS islands) (CC and) (NN island) (NNS chains))))))))))))) (. .)))
Submarine eruptions may produce seamounts which may break the surface to form volcanic islands and island chains.
(ROOT (S (NP (NP (NNS Seamounts)) (SBAR (WHNP (WDT that)) (S (VP (VBP rise) (PP (IN above) (NP (DT the) (NN water) (NN surface))))))) (VP (VBP are) (VP (VBN called) (NP (NNS islands)))) (. .)))