(S (S (BASENP (DT The) (NN explosion)) (VP (VBD sent) (NP (BASENP (JJ volcanic) (NN ash)) (SBAR (WHNP (WDT which)) (S (VP (VP (VBD spread) (PP (TO to) (QT (DQL ``) (NP (NP (BASENP (NNP Homer)) (COMMA ,) (BASENP (NNP Anchor) (NNP Point))) (CONJP (COMMA ,) (CC and)) (BASENP (NNP Seldovia))) (DQR '')))) (PP (TO to) (NP (BASENP (DT an) (NN altitude)) (PP (IN of) (BASENP (QP (RB over) (NN 50,000)) (NNS feet))))))))))) (PERIOD .))