Reply to “Comment on `3D Site Effects: A Thorough Analysis of a High-Quality Dataset,' by F. J. Chávez-García, J. Castillo, and W. R. Stephenson,” by R. Paolucci and E. Faccioli

We thank R. Paolucci and E. Faccioli for their interest in our article. We will refer to their comments (Paolucci and Faccioli, 2003) as P&F. The article commented on by P&F is Chavez-Garcia et al. (2002) (CCS from here onward), where we presented results of a detailed analysis of the 10 events that were best recorded by the temporary seismograph array installed at Parkway, Wainuiomata, New Zealand, during 1995. Our article followed a first round of analysis (Chavez-Garcia et al. , 1999) that concentrated on frequency domain transfer functions for all the stations (64 events were considered in that article). We kindly ask the interested reader to look into those articles, where the history of the network, geological conditions, and so on, were described. Other articles of the Parkway saga are Stephenson (2000, 2002) and Yu and Haines (2003). The results of the analysis by CCS showed clearly that the more significant part of ground-motion response at this valley was the generation of local surface waves, which contributed both to the large amplitude of the “resonance peak” and to the duration of ground motion on the soft soils of this valley. This result was quite robust for all the events that were analyzed. However, Paolucci et al. (2000), analyzing the records for a single event at Parkway at 10 soft soil stations (from the 13 recorded for this earthquake), came to a very different conclusion: “In the case of Parkway Valley we identified what is probably one of the first clear cases of evidence of a 2D resonance mode” (p. 5). This 2D resonance, according to Paolucci et al. (2000), is that of the fundamental in-plane mode, as defined by Bard and Bouchon (1985). CCS felt obliged to confront this discrepancy and gave some arguments against the interpretation …