Monitoraggio della frana di Corniglio (Parma) prima e dopo il terremoto di magnitudo M=5.4 del Dicembre 2008

In this work we present the results of a recent monitoring of a large landslide by means of integration of several techniques. The site is the Corniglio landslide (CL). We integrate traditional geomorphologic and geological surveys, digital photogrammetry, GPS monitoring and geostatistics, to propose a new kinematic framework for the CL as Deep-Seated Slope Gravitational Deformation (DSGSD). Surveys were carried out in six periods, in July and September 2006, March and August 2007, July 2008 (after a M=4 earthquake in 28 December 2007, 10 km far from Corniglio), and finally January 2009 (after several earthquakes in the last days of December 2008 with magnitude variable from 4 to 5.4, and with epicentres located less than 30 km far from Corniglio). Survey results, photogeologic interpretation of multitemporal orthophotographs, related to 1976, 1988, 1994, 1996, 1998, 2005, and satellite imagery related to 2003 were integrated for analysing the state of activity of landslide from 1976 to 2009, quantifying the superficial displacement vectors. Moreover, a GPS survey by RTK mode was periodically performed to locate the actual crown of the main scarp and to identify movements of the CL after the earthquakes of the end of December 2008. The relevant east-west trending lineaments seem to be involved into slope movements. These evidences suggests that the CL may be part of a larger DSGSD also including the hill among the Bratica river, the CL main body and the Parma river, and it is subjected to the important earthquakes involving this area, which periodically reactivate the main body of landslide.