We present a collection of pictures of the coseismic secondary geological effects produced on the
environment by the 2012 Emilia seismic sequence in northern Italy. The May-June 2012 sequence struck a
broad area located in the Po Plain region, causing 26 deaths and hundreds of injured, 15.000 homeless,
severe damage of historical centres and industrial areas, and an estimated economic toll of ~2 billion of
euros. The sequence included two mainshocks (Figure 1): the first one, with ML 5.9, occurred on May 20
between Finale Emilia, S. Felice sul Panaro and S. Martino Spino; the second one, with ML 5.8, occurred 12
km southwest of the previous mainshock on May 29. Both the mainshocks occurred on about E-W trending,
S dipping blind thrust faults; the whole aftershocks area extends in an E-W direction for more than 50 km
and includes five ML≥5.0 events and more than 1800 ML>1.5 events. Ground cracks and liquefactions were
certainly the most relevant coseismic geological effects observed during the Emilia sequence. In particular,
extensive liquefaction was observed over an area of ~1200 km2 following the May 20 and May 29 events.
We collected all the coseismic geological evidence through field survey, helicopter and powered hang-glider
trike survey, and reports from local people directly checked in the field. On the basis of their morphologic
and structural characteristics the 1362 effects surveyed were grouped into three main categories: a)
liquefactions related to overpressure of aquifers, occurring through several aligned vents forming coalescent
flat cones (485 effects); b) liquefactions with huge amounts of liquefied sand and fine sand ejected from
fractures tens of meters long (768); c) extensional fractures with small vertical throws, apparently organized
in an en-echelon pattern, with no effects of liquefaction (109). The photographic dataset consists of 99
pictures of coseismic geological effects observed in 17 localities concentrated in the epicentral area. The
pictures are sorted and presented by locality of observation; each photo reports several information such as
the name of the site, the geographical coordinates and the type of effect observed. Figure 1 shows a map of
the pictures sites along with the location of the two mainshocks; Figure 2 shows a detail of the distribution of
the liquefactions in the area of S. Carlo. The complete description of the coseismic geological effects
induced by the Emilia sequence, their relation with the aftershock area, the InSAR deformation area and the
I>6 EMS felt area, along with the description of the technologies used for data sourcing and processing are
shown in Emergeo Working Group [2012a and 2012b].Published1-703.2. Tettonica attivaN/A or not JCRope
