COMMENTS

The source included in the Database is mainly derived from Piccardi (1999). This 
source is attributed a prevalently dextral movement. 

The new estimate of Me (equivalent magnitude from felt reports) of 6.2 attributed to 
the 6 December 1875 San Marco in Lamis earthquake in CPTI (1999) gives a 
substantially higher seismic potential to this source. This in agreement with the 
geometry and size assigned to it in the Database. 

Defining the present activity of the Mattinata Fault is the main issue for this source. 
The fault geomorphology is certainly impressive but a long tectonic history may have 
left a very strong geomorphic signature, especially durable in the calcareous rocks, 
that may make the fault appear still active even though it is not. This has been 
observed for other faults in calcareous rocks in the Apennines. Moreover, according 
to Argnani et al. (1993) no important deformation is seen offshore on the 
prolongation of the Mattinata Fault since Early Pliocene. However, seismicity occurs 
on this structure with small and moderate earthquakes possibly up to M 6.2.


OPEN QUESTIONS

1) The Mattinata Fault is known as an important crustal structure with a long tectonic 
history. However, its evolution and kinematics are the matter of debate among 
structural geologists. Is this fault presently active? Is it a potential seismic source? If 
this is the case, is it a dextral or sinistral strike-slip fault?

2) Could the three portions of the Mattinata Fault defined by Piccardi (1998) and 
included in this Database be considered as fault segments in the sense of Schwartz and 
Coppersmith? If this is the case, how well defined are the segment boundaries? 

3) Conversely, can the three fault sections be part of a single larger seismogenic 
source?

4) Has the 6 December 1875 (Me=6.2) earthquake ruptured this source for its entire 
length?
