Vari (1930)
This worker documents ground deformation, mainly fractures and landslides, 
located in the epicentral area. A large landslide was activated at S. Giorgio La 
Molara and the Tammaro river was diverted by the huge amount of material 
falling in. Important fractures were seen on the road between Zungoli and 
Villanova del Battista and at Rocchetta S. Venere villages, on the left bank of 
the Ofanto river. The S. Angelo hill, located close to the village of Savignano 
Irpino, subsided sensibly. The author also mentions that the duration of the 
earthquake was about 35 seconds.

Alfano (1931)
He interprets the long duration of the shaking as due to three different events, 
that gave three intensity peaks in Villanova, Trevico and Lacedonia. The author 
notes that, with respect to the "epicentral line" connecting the mentioned 
villages, the damage distribution was clearly wider to the west. Three 
foreshocks were felt at different times in Frigento, Candela and Gesualdo. 
Several fractures and landslides were reported in the epicentral area, where 
flashes of lightning and explosion-like sounds occurred along with, or nearly 
along with, the shock. A flash of lightning was seen 2 hours before the main 
event in Ariano di Puglia.

Oddone (1932)
This worker reports observations collected in the epicentral area four days 
after the 23 July 1930 event. At San Giorgio La Molara a huge landslide dammed 
and diverted the Tammaro river. Several fractures formed over a wide area: 
the most interesting features were (1) a NW-SE striking fracture, running from 
the damaged S. Spirito bridge, on the Miscano river, to Foiano sul Fortore, (2) 
a 60 cm-wide and 40 cm-deep fracture striking N-S at Masseria Novario, and (3) 
a large fracture on the road between Montecalvo Irpino and Corsano. The author 
also mentions a foreshock felt at Anzano two hours before the main event.

Ciaranfi et al. (1983)
This workers trace a 30-40 km-long, NW-SE striking, west dipping normal fault 
from Monteverde to Savignano Irpino.

Martini and Scarpa (1983)
This paper presents a first motion focal mechanism which indicates normal 
faulting with a small horizontal component along roughly E-W striking planes.

Jimenez (1991)
This worker analysed long-period records of a single station (Jena, DDR) for 
the 23 July 1930 Irpinia earthquake. He obtains two focal  mechanisms using two 
different velocity models of the Irpinia region; the first solution indicates 
strike-slip faulting along approximately N-S and E-W striking planes, while the 
second (preferred by the author) shows a similar direction of the principal 
stress with predominant normal faulting.

Selvaggi et al. (1997)
He presents a fault plane solution which indicates predominant normal faulting 
along roughly E-W striking planes. The focal mechanism is based on selected P-
wave polarities.

Gasperini et al. (1999)
Based on a method that analyses macroseismic intensity data, these workers 
determine the location, the physical dimensions, and a 10811 azimuth for the 
source of the 23 July 1930 earthquake.

