( Geysers ( ( form ( when ( ( hot water ) ( erupts ( to ( the surface ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Geysers)) (VP (VBP form) (SBAR (WHADVP (WRB when)) (S (NP (JJ hot) (NN water)) (VP (VBZ erupts) (PP (TO to) (NP (DT the) (NN surface))))))) (. .)))
Geysers form when hot water erupts to the surface.
(ROOT (S (NP (NNS Geysers)) (VP (VBP are) (VP (VBN created) (SBAR (WHADVP (WRB when)) (S (NP (NN water)) (VP (VBZ is) (VP (VBN heated) (PP (IN beneath) (NP (NP (DT the) (NN earth) (POS 's)) (NN surface))))))))) (. .)))