( ( ( A tiltmeter ) ( at ( ( the bottom ) ( of ( this bore-hole ) ) ) ) ) ( ( is ( used ( to ( ( measure deformation ) ( at ( ( the base ) ( of Teide ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT A) (NN tiltmeter)) (PP (IN at) (NP (NP (DT the) (NN bottom)) (PP (IN of) (NP (DT this) (NN bore-hole)))))) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB measure) (NP (NN deformation)) (PP (IN at) (NP (NP (DT the) (NN base)) (PP (IN of) (NP (NNP Teide)))))))))) (. .)))
A tiltmeter at the bottom of this bore-hole is used to measure deformation at the base of Teide.
(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))))))))))) (. .)))