( ( Geophysical observations ) ( ( suggest ( that ( ( ( the ( Earth 's ) ) ( magnetic field ) ) ( is ( generated ( within ( ( the liquid ) ( of ( ( the ( Earth 's ) ) ( metallic ( outer core ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Geophysical) (NNS observations)) (VP (VBP suggest) (SBAR (IN that) (S (NP (NP (DT the) (NN Earth) (POS 's)) (JJ magnetic) (NN field)) (VP (VBZ is) (VP (VBN generated) (PP (IN within) (NP (NP (DT the) (NN liquid)) (PP (IN of) (NP (NP (DT the) (NN Earth) (POS 's)) (JJ metallic) (JJ outer) (NN core)))))))))) (. .)))
Geophysical observations suggest that the Earth's magnetic field is generated within the liquid of the Earth's metallic outer core.
(ROOT (S (NP (DT The) (JJ outer) (NN core)) (VP (VBZ is) (VP (VBN made) (PP (IN of) (NP (JJ liquid) (NN metal))))) (. .)))