( ( ( TSUNAMI ( An ( ocean wave ) ) ) ( with ( ( a ( long period ) ) ( that ( is ( formed ( by ( ( ( ( an ( underwater ( ( earthquake or ) landslide ) ) ) , ) or ) ( volcanic eruption ) ) ) ) ) ) ) ) ) . )
(ROOT (S (VP (VB TSUNAMI) (NP (DT An) (NN ocean) (NN wave)) (PP (IN with) (NP (NP (DT a) (JJ long) (NN period)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (VP (VBN formed) (PP (IN by) (NP (NP (DT an) (JJ underwater) (NN earthquake) (CC or) (NN landslide)) (, ,) (CC or) (NP (JJ volcanic) (NN eruption))))))))))) (. .)))
TSUNAMI An ocean wave with a long period that is formed by an underwater earthquake or landslide, or volcanic eruption.
(ROOT (S (NP (DT A) (-LRB- -LRB-) (NN n) (-RRB- -RRB-) (NN underwater) (NN earthquake)) (VP (VBZ creates) (NP (DT a) (NN tsunami))) (. .)))