Ghisetti and Vezzani (1980)
Based on a microtectonic analysis, these workers investigate the possible 
influence of tectonics on the Iblean plateau and foreland margin during the 
Plio-Pleistocene. In contrast with the well-accepted extensional tectonic 
models, many of the data collected in this study refer to wrenching mechanisms, 
in particular lateral shear. Morphotectonic evidence suggests the extensional 
phase, which affected all the existing planes, to be more recent and still 
active. In agreement with paleomagnetic data, they also hypothesise a clockwise 
rotation of Sicily with respect to the stable Iblean area during neotectonic 
times. 

Barbano and Cosentino (1981)
They perform a detailed macroseismic analysis of the 11 January 1693 earthquake 
and point out that this event occurred in one of the most seismically active 
areas struck also by the 1140, 1169 and 1542 earthquakes. The isoseismals 
showing a NNE-SSW elongation are associated by the authors to structures that 
focalized energy.  Based on the occurrence of the tsunami and on the shape of 
the isosesmals they locate the epicenter offshore between Augusta and Catania 
and suggest a possible normal faulting geometry for the source. In their 
interpretation the large earthquakes that occurred in this area are generated on 
the eastern margin of the Iblean plateau where it joins the NNW-SSE Ibleo-
Maltese escarpment. Finally, they attribute a magnitude of M 7.7-7.8 to the 1693 
event. 

Lombardo (1985)
This investigator analyses the 4 February 1169 earthquake. Taking into 
account the great difficulties and uncertainties due to the age of the event, 
the author concludes that this earthquake struck the same area hit by the 
1693 event with comparable intensity. Moreover, the author suggests that 
both these events occurred offshore close to the coastline.

Mulargia et al. (1985)
This paper analyses the historical seismicity of southestern Sicily. The authors 
discuss the complex tectonic setting of the region in relation with the most 
significant earthquakes. Using geodetic levelling compared with sedimentological 
and tidal data they suggest that the area is undergoing an accelerated 
deformation process, and based on a statistical approach they propose the 
existence of a seismic gap.

D'Addezio and Valensise (1991)
These workers discuss the distribution and elevation of marine terraces as well 
as the attitude of lower Pleistocene sediments in the framework of the 
topographic and geologic setting of the area struck by the 13 December 1990 
earthquake. Based on historical, geological and geomorphological observation 
they hypothesise an ENE-WSW trending, SSW dipping, low-angle blind normal fault 
located below the Scordia-Lentini graben as the seismogenic source responsible 
for the largest events of the area (i.e. the 1169 and 1693 events). 

Grasso et al. (1992)
They perform a geological and structural analysis in the southeastern part of 
the Iblean plateau, a region characterized by dextral transpression along the 
NE-SW trending Ispica fault zone. Their analysis indicates that this fault acted 
as a normal fault until the Middle Pliocene, and that after this period the area 
underwent compression up to Middle Pliestocene. The Ispica fault splays offshore 
from the almost N-S trending Scicli transform fault system, which is considered 
active by the authors on the basis of seismological and morphotectonic evidence. 
Taking into account that the Pantelleria Rift implies extension in the NE-SW 
direction, the authors suggest that 1) the Ispica fault could directly 
accommodate the extension or that 2) dextral movement along the Scicli fault may 
have triggered dextral motion on the Ispica Fault.

Hirn et al. (1997)
These investigators use several seismic profiles to outline the deep structure 
of Etna and its Ionian margin. Based on marine seismic profiles the authors 
document at a regional scale the presence of a succession of superficial recent 
sedimentary half-grabens bounded to the W by steep, east-facing normal faults 
and filled by a westward dipping wedge of sediments. These faults provide clear 
evidence of present-day activity and are seen as good candidates for the 
source of big earthquakes such as those that occurred in 1169 and 1693. The 
authors contend that there could be a coupling in time between the occurrence of 
large eruptions of Mt. Etna and the occurrence of large earthquakes. 

Piatanesi and Tinti (1998)
Based on historical data these workers propose a revision the 1693 tsunami. They 
focus on the first motion of sea water and use this information to constrain the 
the seismogenic source. They simulate tsunamis from different possible sources 
using a numerical model and compare the models obtained with the available 1693 
data. They indicate an offshore fault system parallel to the Iblean-Maltese 
escarpment as a possible source for the 1693 earthquake that satisfyes all 
constraints imposed by the data. In addition, they suggest that the macroseismic 
data for the 11 january shock are probably corrupted by the strong foreshock 
that occurred 2 days earlier. 

Azzaro and  Barbano (1999)
They analyse macroseismic, seismometric and geostructural data to investigate 
seismogenic features of southeastern Sicily. They propose a model of segmented 
seismogenic faults and their main seismotectonic parameters. They also indicate 
the Ibleo-maltese escarpment as the only structure capable of generating 
earthquakes with M>7 such as the 1169 and the 1693 events. Secondary seismogenic 
zones (capable of M<6.5 events) are the Scicli Line and the NE-SW fault system 
bounding the Iblean plateau to the North.

Bianca et al. (1999)
These workers use geological and morphological data combined with the analysis 
of several seismic reflection lines and historical seismicity to describe active 
faulting in southeastern Sicily. They identify an important fault system that 
developed since 240 ky and is characterised by a vertical throw rates of 0.7-3.3 
mm/yr. The system is formed by NNW-SSE-striking normal fault segments along the 
Ionian offshore and by the NE-SW-trending Avola and Rosolini-Ispica normal 
faults, the former thought to be responsible for the 11 January 1693 earthquake.
The authors suggest the 1693 event could be related to a 45 km long normal fault 
with right lateral component, slipping at a long term rate of 3.7 mm/yr and with 
recurrence time for 1693-type earthquakes of 55050 years.

Ragg et al. (1999)
These workers analyse the orientation of in situ tectonic stress deduced from 
borehole breakout data in Sicily. They separate several tectonic units with 
characteristic stress patterns. For southeastern Sicily they find a NNW-SSE 
orientation of the maximum horizontal stress. The authors also remark that a 
large transfer zone (the Arcate, Comiso and Scicli fault systems) accommodate 
different rates of spreading of the Pantelleria Rift by dextral movement. 

Sirovich and Pettenati (1999)
These workers use a new scheme for the inversion of macroseismic data of the two 
largest 1693 earthquakes to retrieve information on their causative source. They 
first summarise the seismotectonic information and interpretations available for 
the region to provide geometrical and kinematic constrains for quantitative 
modelling. The transfer system that connects the Sicily Straits rift system and 
the Simeto-Scordia-Lentini graben appears to the authors as a good candidate for 
the 9 January 1693 earthquake source. A similar source is obtained for the 11 
January shock, but considering the available seismotectonic data and the 
occurrence of a tsunami, the authors suggest this earthquake could have been 
generated either by the transfer system or by a fault located along the Ibleo-
Maltese escarpment. 

Stucchi and Albini (1999)
This paper points out the possible influence of the 9 January 1693 earthquake on 
the assessment of damage caused by the 11 January event. A separate examination 
of the effect produced by the two shocks allows these workers to estimate the 
earthquake parameters. The source azimuth suggested by the distribution of 
intensities is in agreement both with the Scicli system and with the Ibleo-
maltese escarpment, whereas the location of the epicenter is thought to be more 
consistent with the Scicli system.
