Puglisi, C.

We provide a database of the coseismic geological surface effects following the Mw 6.5 Norcia earthquake that hit central Italy on 30 October 2016. This was one of the strongest seismic events to occur in Europe in the past thirty years, causing complex surface ruptures over an area of >400 km2. The database originated from the collaboration of several European teams (Open EMERGEO Working Group; about 130 researchers) coordinated by the Istituto Nazionale di Geofisica e Vulcanologia. The observations were collected by performing detailed field surveys in the epicentral region in order to describe the geometry and kinematics of surface faulting, and subsequently of landslides and other secondary coseismic effects. The resulting database consists of homogeneous georeferenced records identifying 7323 observation points, each of which contains 18 numeric and string fields of relevant information. This database will impact future earthquake studies focused on modelling of the seismic processes in active extensional settings, updating probabilistic estimates of slip distribution, and assessing the hazard of surface faulting.

We present a 1:25,000 scale map of the coseismic surface ruptures following the 30 October 2016 M-w 6.5 Norcia normal-faulting earthquake, central Italy. Detailed rupture mapping is based on almost 11,000 oblique photographs taken from helicopter flights, that has been verified and integrated with field data (>7000 measurements). Thanks to the common efforts of the Open EMERGEO Working Group (130 people, 25 research institutions and universities from Europe), we were able to document a complex surface faulting pattern with a dominant strike of N135 degrees-160 degrees (SW-dipping) and a subordinate strike of N320 degrees-345 degrees (NE-dipping) along about 28km of the active Mt. Vettore-Mt. Bove fault system. Geometric and kinematic characteristics of the rupture were observed and recorded along closely spaced, parallel or subparallel, overlapping or step-like synthetic and antithetic fault splays of the activated fault systems, comprising a total surface rupture length of approximately 46km when all ruptures were considered.

This paper illustrates a geographic information system (GIS) supported methodology for the assessment of landslide susceptibility. The methodology involves four operational steps: survey, site analysis, macro- area analysis and susceptibility analysis . The Survey includes the production (or acquisition) of a large-scale litho-technical map, a large-scale geomorphological map, a detailed inventory of past and present land- slide events, and a high resolution DTM (Digital Terrain Model. Site analysis leads to the definition of discriminating parameters (commonly, lithological and morphometric conditions necessary but not suffi- cient to trigger a landslide of a given type) and predisposing factors (conditions that worsen slope stability but are not sufficient to trigger a landslide of a given type in the absence of discriminating parameters ). The different predisposing factors are subdivided into classes, whose intervals are established by descriptive, statistical analysis of landslide inventory data. A numerical index, based on the frequency of landslide occurrence, quantifies the contribution of each class to slope instability. Macro-area analysis includes the generation of Litho-Morphometric Units (LMU) by overlaying discrimina- ting parameters , manual drawing of LMU envelopes ( macro-areas ), generation of predisposing factor maps from the spatial distribution of predisposing factors , and heuristic weighting of predisposing factor indices. Susceptibility analysis includes the generation of Homogeneous Territorial Units (HTU) by overlaying macro- areas and predisposing factor maps , and the application of a susceptibility function to the different HTU. The resulting values are normalized before the generation of the landslide susceptibility maps . The methodo- logy has been applied to the Fiumicino River catchment, located in the western side of Latium Apennine (Central Italy) between 200 and 1300 m a.s.l. and developed on Late Miocene calcarenites, sandstones with clay intercalations, and marls. The resulting landslide susceptibility maps will be employed in envi- ronmental management. They also represent the preliminary step for the assessment of landslide hazard and risk

GIS methodology to assess landslide susceptibility: application to a river catchment of central Italy This paper illustrates a GIS supported methodology for the assessment of landslide susceptibility. The methodology involves four steps: survey, site analysis, macro-area analysis, and susceptibility analysis. Statiscal and GIS processing of basical large scale geological dataset leads to the recognition of discriminating parameters (land conditions necessary but not sufficient to trigger landslides) and predisposing factors (conditions that worsen slope stability) separately for each landslides types. The susceptibility function combines GIS data to draw landslide susceptibility maps. These results represent the preliminary step for the assessment of landslide hazard and risk.