( ( Networks ( of ( continuously ( measuring ( ( ( GPS receivers ) and ) ( electronic tiltmeters ) ) ) ) ) ) ( ( ( are now ) ( commonly ( found ( on ( volcanoes ( that ( are monitored ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Networks)) (PP (IN of) (S (VP (ADVP (RB continuously)) (VBG measuring) (NP (NP (NNP GPS) (NNS receivers)) (CC and) (NP (JJ electronic) (NNS tiltmeters))))))) (VP (VBP are) (ADVP (RB now)) (VP (ADVP (RB commonly)) (VBN found) (PP (IN on) (NP (NP (NNS volcanoes)) (SBAR (WHNP (WDT that)) (S (VP (VBP are) (VP (VBN monitored))))))))) (. .)))
Networks of continuously measuring GPS receivers and electronic tiltmeters are now commonly found on volcanoes that are monitored.
(ROOT (S (NP (NNS Tiltmeters)) (VP (VBP are) (VP (VBN used) (S (VP (TO to) (VP (VB measure) (NP (NP (DT the) (NN angle)) (PP (IN of) (NP (NP (DT the) (NN slope)) (PP (IN of) (NP (DT a) (NN volcano))))))))))) (. .)))