(S (SBAR (SINV (VBD Had) (S (BASENP (DT any) (NN civilization)) (VP (VBN existed) (PP (IN on) (BASENP (DT the) (JJ frozen) (NN ice) (NN cap))))))) (COMMA ,) (S (BASENP (DT the) (NNP USGS)) (VP (VBZ says) (SBAR (IN that) (S (BASENP (NN damage)) (VP (MD could) (VP (VB be) (QT (DQL ``) (QTC (ADJP (JJ light) (CC to) (JJ moderate)) (PERIOD .)) (DQR '')))))))))