Investigation of pre-1700 Earthquakes Between the Adda and the Middle Adige River Basins (Southern Alps) - Historical Seismology: Interdisciplinary Studies of Past and Recent Earthquakes - page 111

which would have happened in 1185. Recently Guidoboni and Comastri (2005),
reappraising the same information used by Boschi et al. (1995 and 2000), assign I
6-7 MCS at Verona, and propose for the earthquake the date December 1183.

3.3.3.2 1491, Verona-Padova (?)

This earthquake is reported in Postpischl (1985a) with date August 1492, located in
the Verona area with Io 8 MCS. Boschi et al. (1995; 2000) date the earthquake on
1491 and identify two damaged localities (Fig. 12), Verona (I 8 MCS) and Padova (I 7
MCS). However, no contemporaneous sources have been found for Verona. Moreover
for Padova, according to documents in the State Archive of Padova (quoted in Boschi
et al., 1995; 2000), a heavy snowfall increased the damage to the roofs. Guidoboni and
Comastri (2005) reappraised the sources related to Verona and concluded that “there
seems to be no justification for the attribution to Verona of an intensity of grade 8 MCS
given in Boschi et al. (1995; 1997; 2000)” . Therefore, the authors cancel Verona from
the list of the damaged localities (Fig. 12). Moreover, the intensity at Padova, reduced
at I 6-7 MCS, is considered doubtful due to the quoted climatic effects. In the whole,
the earthquake occurrence itself seems questionable. If the earthquake really occurred,
it should not be related to the Verona area.

3.4 The Earthquake of 1222

This earthquake has been the object of several studies (Magri and Molin, 1986; ENEL,
1985; ENEL, 1986b; Guidoboni, 1986; Boschi et al., 1997; 2000) which, through time,
have decreased the size it had in the previous catalogues. The most recent review on
this event has been published in Guidoboni and Comastri (2005). Available infor-
mation from primary sources defines a significant damage to Brescia. According to
the mentioned authors, however, the city was not completely destroyed as, with great
emphasis, is reported in the primary sources. Intensity at Brescia has been estimated
I 8 MCS. A higher damage (I 9 MCS) probably affected some villages of the Brescia
diocese, corresponding to the present province of Brescia, particularly in the Southern
area; however, this damage cannot be exactly located. Damage is also attributed to the
villages of Lazise (in the Lake Garda area, I 7-8 MCS), Marano di Valpolicella (in the
Verona area, I 7-8 MCS), Modena (I 7 MCS) and, probably, Milano (6 MCS). The
earthquake was felt in varied towns and villages of Northern Italy (Fig. 13); however,
Guidoboni and Comastri (2005) reduce the number of macroseismic observations
from the 39 published in Boschi et al. (2000) to only 20.
The current epicentral location is problematic, due to the uncertainty in the inten-
sity assignment at the known places and the impossibility to identify the localities of
the Brescia diocese which suffered damage. For this reason, the algorithms defining
the epicentral location, such as “Boxer” (Gasperini et al., 1999) are strongly con-
ditioned by the known localities east of Brescia; therefore, the epicentral location
some tens of kilometres east of Brescia is probably not precise. These aspects also
condition the determination of the magnitude which the CPTI04 catalogue assesses
as 6

. 05 ± 0 . 13 Mw.