(S (S (S (BASENP (DT This)) (VP (VBZ is) (BASENP (DT a) (JJ so-called) (JJ deep-focus) (NN earthquake)))) (COMMA ,) (S (BASENP (DT that)) (VP (VBZ 's) (SBAR (WHADVP (WRB why)) (S (BASENP (PRP it)) (VP (VBD was) (VP (VBN felt) (PP (IN at) (BASENP (PDT such) (DT a) (JJ large) (NN territory)))))))))) (PERIOD .))