INACCURACIES IN SEISMICITY AND MAGNITUDE DATA USED BY VAROTSOS AND COWORKERS - REPLY

A direct comparison of the predicted magnitude values (M(pred)) to the actual magnitude values (M(EQ)) of the earthquakes (EQs) is allowed o nly when both values, i.e., M(pred) and MEQ, refer to the same scale. In view of the fact that the Seismological Institute of the National O bservatory of Athens (SI-NOA) publicly announces as MEQ the M(L)+0.5 v alue (Where ML the local magnitude), VAN made it clear long ago, that the predicted values M(pred) (after a proper calibration) referred to M(L)+0.5. Therefore, a self-consistent evaluation of VAN-predictions s hould consist of a direct comparison of M,red with the actual M(L)+0.5 . Unfortunately, Wyss [1996] confuses the discussion by proceeding to a direct comparison of M(pred) With M(s)(PDE); this is not allowed bec ause the values of M(L)+0.5 exceed, on the average, M(s)(PDE) by 1.0 u nit. An additional confusion arises from the fact that the relation su ggested by Hamada [1993], i.e., M(L)+0.5=m(b)+0.3, is misinterpreted b y Wyss as saying M(s)(PDE)=m(b)+0.3. These two alterations by Wyss rev eal that his Figures 1 and 2 are erroneous. Wyss [1996] also criticize s VAN, because (in an early publication) Varotsos et al. [1981b] used the Preliminary Bulletin of SI-NOA, instead of the final one. First of all, the final bulletin could not be used by VAN at that time, becaus e it appeared (more than one year) after the publication of the paper by Varotsos et al. [1981b]. Secondly, the correlation between SESs and EQs is evident,when we use consistently, either the preliminary, or t he final bulletin of SI-NOA. On the other hand, Wyss [1996] claims tha t he could not find any correlation between EQs and SESs; we show that this is due to the fact that Wyss included, in his study, small EQs t hat occurred several hundreds km away from the measuring VAN station ( i.e., in Albania, western Turkey, etc.), but he simultaneously deleted the small magnitude EQs that occurred very close to that station. Wys s's procedure is, of course, not acceptable and hence his Appendix B i s wrong. Furthermore, Wyss's claim that VAN added 25% of events to the list, is shown to be untrue. Beyond the unusual fact that Wyss quotes ''VAN's statements'' that have never been published by VAN, the follo wing is also noted: although Wyss [1996] uses quotation marks (in orde r to indicate that he reproduced exactly what VAN said), he adds criti cal wording to VAN statements and hence their true meaning is drastica lly changed. For example, Wyss states: ''Varotros et al. [l981a] had f irst formulated that SESs ''occurred a few minutes before each earthqu ake [related to that SES]'' (Varotsos et al. [1981a]).'' Thus, Wyss le ads the reader to the wrong conclusion that VAN initially claimed that SES have a lead time of a few minutes, and that VAN changed it later. However, we show that this lead time (published by VAN) referred to a nother the of precursor, and not to SES, but the words in brackets (wh ich are added by Wyss) alter the true meaning of our statement.