( ( Earthquakes ( in Ecuador ) ) ( ( ( stem ( from ( ( ( two ( major ( ( interrelated tectonic ) areas ) ) ) : ) ( ( the subduction ) ( of ( the ( Nazca Plate ) ) ) ) ) ) ) ( under ( ( ( the ( South ( American Plate ) ) ) and ) ( the ( Andean ( Volcanic Belt ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Earthquakes)) (PP (IN in) (NP (NNP Ecuador)))) (VP (VBP stem) (PP (IN from) (NP (NP (CD two) (JJ major) (ADJP (JJ interrelated) (JJ tectonic)) (NNS areas)) (: :) (NP (NP (DT the) (NN subduction)) (PP (IN of) (NP (DT the) (NNP Nazca) (NNP Plate)))))) (PP (IN under) (NP (NP (DT the) (NNP South) (NNP American) (NNP Plate)) (CC and) (NP (DT the) (JJ Andean) (NNP Volcanic) (NNP Belt))))) (. .)))
Earthquakes in Ecuador stem from two major interrelated tectonic areas: the subduction of the Nazca Plate under the South American Plate and the Andean Volcanic Belt.
(ROOT (S (NP (DT A) (JJ volcanic) (NN arc)) (VP (VBZ is) (VP (VBN formed) (SBAR (WHADVP (WRB when)) (S (NP (DT a) (VBG subducting) (NN plate)) (VP (VBZ flows) (PP (IN under) (NP (DT another) (JJ tectonic) (NN plate)))))))) (. .)))