(S (S (PP (VBG According) (PP (TO to) (BASENP (DT the) (NNP U.S.) (NNP Geological) (NNP Survey)))) (COMMA ,) (S (ADVP (RB however)) (COMMA ,) (S (BASENP (DT a) (NN 5.7) (NN magnitude) (NN quake)) (VP (VP (VBD occurred) (PP (IN at) (NP (BASENP (NN 0117)) (BASENP (NN UTC))))) (S (VP (VP (VBN followed) (PP (IN by) (NP (BASENP (DT an) (NN earthquake)) (PP (IN of) (BASENP (NN 4.7) (NN magnitude)))))) (ADVP (BASENP (NN fifteen) (NNS minutes)) (RB later)))))))) (PERIOD .))