( It ( ( ( is usually ) ( determined ( ( ( by ( measuring ( ( the amplitude ) ( -LRB- ( height -RRB- ) ) ) ) ) or ) ( by ( modeling ( ( the character ) ( of ( ( the ( earthquake waves ) ) ( recorded ( by ( a seismograph ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ is) (ADVP (RB usually)) (VP (VBN determined) (PP (PP (IN by) (S (VP (VBG measuring) (NP (NP (DT the) (NN amplitude)) (PRN (-LRB- -LRB-) (NP (NN height)) (-RRB- -RRB-)))))) (CC or) (PP (IN by) (S (VP (VBG modeling) (NP (NP (DT the) (NN character)) (PP (IN of) (NP (NP (DT the) (NN earthquake) (NNS waves)) (VP (VBN recorded) (PP (IN by) (NP (DT a) (NN seismograph))))))))))))) (. .)))
It is usually determined by measuring the amplitude (height) or by modeling the character of the earthquake waves recorded 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))))))))) (. .)))