( ( ( The ( ( rises and ) depressions ) ) ( in ( the ( sea surface ) ) ) ) ( ( are ( caused ( by ( ( local changes ) ( in ( ( Earth 's ) ( gravity field ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NNS rises) (CC and) (NNS depressions)) (PP (IN in) (NP (DT the) (NN sea) (NN surface)))) (VP (VBP are) (VP (VBN caused) (PP (IN by) (NP (NP (JJ local) (NNS changes)) (PP (IN in) (NP (NP (NNP Earth) (POS 's)) (NN gravity) (NN field))))))) (. .)))
The rises and depressions in the sea surface are caused by local changes in Earth's gravity field.
(ROOT (S (NP (NP (DT The) (NN movement)) (PP (IN of) (NP (NP (DT an) (NN air) (NN mass)) (PP (IN over) (NP (NP (NN earth) (POS 's)) (NN surface)))))) (VP (VBZ causes) (NP (JJ local) (NN weather) (NNS changes))) (. .)))