( ( ( ( ( ( A tsunami ) , ) or ) ( tidal wave ) ) , ) ( ( is ( ( a ( huge wave ) ) ( caused ( by ( ( ( ( ( ( seismic movements ) , ) or ) earthquakes ) , ) ( in ( the ocean ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT A) (NN tsunami)) (, ,) (CC or) (NP (JJ tidal) (NN wave)) (, ,)) (VP (VBZ is) (NP (NP (DT a) (JJ huge) (NN wave)) (VP (VBN caused) (PP (IN by) (NP (NP (NP (JJ seismic) (NNS movements)) (, ,) (CC or) (NP (NNS earthquakes)) (, ,)) (PP (IN in) (NP (DT the) (NN ocean)))))))) (. .)))
A tsunami, or tidal wave, is a huge wave caused by seismic movements, or earthquakes, in the ocean.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NP (DT the) (NN energy)) (PP (IN of) (NP (DT the) (NN earthquake)))) (VP (VBZ reaches) (VP (NN shore))))) (, ,) (NP (PRP it)) (VP (VBZ forms) (SBAR (S (NP (DT a) (JJ huge) (NN wave)) (VP (VBD called) (NP (DT a) (NN tsunami)))))) (. .)))