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CEPPO MORELLI (Italy, North-western Alps)
1. Description of the site
 The Ceppo Morelli rockslide extends on the left side of the Anzasca valley in northern Piedmont (Italy), few kilometres from the border with Switzerland. The slides affects a massive gneiss formation along a cataclinal overdip slope and may be regarded as a quasi-planar rock slide. The main movement occurs along a master continuous foliation surface, strongly defined by mica layer and dipping about 35°. Moreover it seems extremely likely that, on the front part of the slide body, the sliding surface follows a stepped path which involves both the main and a secondary, steeper, foliation. The overall surface of the slide is in the order of 150.000 m²; the volume estimation is between 4 and 6 *106 m3.
The slope sector where the main sliding surface daylights, 400 m about above the talweg, is a continuous source of rockfalls reaching the Anza river. Boulders up to 1000 m3 are not uncommon.
The main slide body is divided in two main portions, a lower one, where the rockmass, although traslated, is still ordered, and an upper one, constituted by very coarse debris. The lower part is apparently strongly instable and may well give origin to mass-falls or even to a rock avalanche.
2. Hazard analysis
Historical research gave information among the oldest in Europe. A chronicle dating from the XV century reports failures in the years 312 and 843; in the latter episode 25 knights were killed (allegedly carrying a sort of treasure). In order to be still vivid in the local history after several centuries (most of which lacking written reports) the quoted events probably refers to mass-failures rather than simple rock falls.
The year of the fall, 1816, in engraved on a 1000 m3 boulder close to the Anza river. Local residents report that rock falls are extremely common. In April 1977 some boulders up to 1000 m3 reached the talweg.
During the flood of October 2000 several boulders, up to 300 m3, reached the river and the National Road. The surveys carried out afterwards indicated an overall downward movement of the main slide body of about 5 m.
From November 2000 the slide is monitored by means of an automated data recording and transmission system which includes: 25 topographic bench-marks controlled by an automated theodolite; 10 wire extensometers; 3 geophones; 1 rain-gauge.
All the data are transmitted by means of GSM modules. Up to now no relevant displacements were detected. Future investigation will define the geologic setting, the precise geometry of the slide body and the probability of major failures.
3. Elements at risk
The National Road N. 549, which runs on the valley bottom, was reached by several boulders both in 1977 and 2000. The road is the only connection to Macugnaga, a popular tourist resort close to the Monte Rosa. In order to avoid the sector at risk (800 m about) a provisional by-pass road was prepared in December 2000. Since this solution will protect from rock falls but not from a mass-fall, a by-pass tunnel is under project.
Major mass-falls may possibly reach two hamlets dating back to the XVI century: Prequartera and Campioli. The Geological Survey of Regione Piemonte (now ARPA Piemonte), along with the Politecnico di Torino, is currently evaluating whether to protect the two hamlets, by means of reinforced earth walls, or to relocate them elsewhere.
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