( ( Like ( the ( Richter ( scale ( to ( measure ( ( the intensity ) ( of ( an earthquake ) ) ) ) ) ) ) ) ) . )
(ROOT (FRAG (PP (IN Like) (NP (DT the) (NNP Richter) (NN scale) (S (VP (TO to) (VP (VB measure) (NP (NP (DT the) (NN intensity)) (PP (IN of) (NP (DT an) (NN earthquake))))))))) (. .)))
Like the Richter scale to measure the intensity of an earthquake.
(ROOT (S (NP (NNS Seismologists)) (ADVP (RB originally)) (VP (VBD measured) (NP (NP (DT the) (NN intensity)) (PP (IN of) (NP (DT an) (NN earthquake)))) (PP (IN with) (NP (DT the) (JJ mercalli) (NN scale)))) (. .)))
Seismologists originally measured the intensity of an earthquake with the mercalli scale.