COMMENTS 

The Database includes in the Norcia Source all faults reported by Blumetti (1995) 
and Cello et al. (1998) as having been activated during the 14 January 1703 earthquake. 
We confirm this hypothesis for all these ruptures, however, based on structural 
considerations we tentatively assign to this source also the Cittareale Fault, which 
according to Blumettis (1995) interpretation ruptured during the 2 February 1703 
earthquake.

On the basis of geomorphic observations, Blumetti (1995) estimates a 0.09-0.2 (pref. 
0.2) mm/yr slip-rate assuming a 100 kyr for the 20 m-high scarp of the western branch 
of the Norcia Fault, that cuts a 230 Kyr paleosol. However, the 230 Kyr age of the 
faulted deposits is the only true constraint on the age of the scarp (i.e., it is certainly 
younger than 230 Kyr). This allows only a minimum slip rate of 0.09 mm/y to be 
estimated, yielding a recurrence time < 10,000 y. Since Cello et al. (1998) contend
that the penultimate event occurred in Roman times, the average recurrence
interval should fall in the range 2,000-10,000.


OPEN QUESTIONS

1) Is there a true direct relation between the historical reports of surface ruptures 
following the 1703 earthquake and the inferred seismogenic sources?

2) What is the average recurrence interval representative for this source? Is it ~5,000 
yr proposed by Blumetti (1995), >10,000 yr as shown by the above calculations, or 1,000 
yr as proposed by Cello et al. (1998)? 

3) Did the 14 January 1703 earthquake rupture only the western fault (Cello et al., 
1998) bounding the Norcia basin, or both the bounding faults (eastern and western) 
were activated?

4) What is the tectonic regime that drives the Norcia Source? Is this source part of a 
crustal, N-striking, strike-slip shear zone (Cello et al. 1997), or is an extensional 
feature as suggested by most geophysical studies (break-out analyses, focal solutions 
and paleoseismology) and other geological studies (e.g. Calamita et al., 1994, among 
many others)?

5) The 19 September 1979 earthquake produced bedrock ruptures along the Ocricchio-
Monte Alvagnano fault zone (Pizzi, 1992; Calamita et al., 1994) and Alvagnano-Castel 
Santa Maria Fault (Blumetti 1995). Is the small source derived from intensity data for 
this earthquake part of the Norcia Source?
