( ( The ( Richter Scale ) ) ( ( describes ( ( ( the magnitudes ) ( -LRB- ( heights -RRB- ) ) ) ( of ( ( seismic waves ) ( measured ( by ( a seismograph ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNP Richter) (NNP Scale)) (VP (VBZ describes) (NP (NP (DT the) (NNS magnitudes)) (PRN (-LRB- -LRB-) (NP (NNS heights)) (-RRB- -RRB-)) (PP (IN of) (NP (NP (JJ seismic) (NNS waves)) (VP (VBN measured) (PP (IN by) (NP (DT a) (NN seismograph)))))))) (. .)))
The Richter Scale describes the magnitudes (heights) of seismic waves measured by a seismograph.
(ROOT (S (NP (NP (DT The) (NN height)) (PP (IN of) (NP (DT the) (NN wave)))) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB determine) (NP (NP (DT the) (NN magnitude)) (PP (IN of) (NP (DT an) (NN earthquake))))))))) (. .)))