Sources from Intensity Data at Higher Confidence Level (Type B sources) were obtained exclusively from the intensity data of an individual large earthquake (M*5

Sources from Intensity Data at Lower Confidence Level

(Type C sources)

These sources were obtained exclusively from the intensity data of an individual large earthquake (M 5.5 or larger) through the Boxer code (Gasperini et al., 1999; available for download from the FAUST Internet site).

The geometric representation of these sources is pseudo-tridimensional. The Boxer code determines the size and orientation of the source, but does not provide any hint on its dip direction, dip angle, depth and kinematics. Therefore in the cartographic interface it is still represented by a rectangle, that is intended to mark the surface projection of the rupture plane, but no indication is given concerning the intersection of this plane with the surface. For a more realistic representataion, the width of the rectangle is shown as if the rupture plane had a dip of 45 degrees. All rectangle edges are precisely located with their N latitude and E longitude. The inferred length and width of the source conclude its geometric description.

The reliability of each source is expressed by two Quality parameters that range from A (most reliable) to E (least reliable). See the description of Rating Criteria for further details.

The recurrence properties of a source derived from intensity data can clearly be represented only by the time elapsed since the latest event.

The description of sources of this category is optionally complemented by:

1) a list of Bibliography that includes the intensity databases from which the intensity data were obtained and any additional papers dealing with the geology, tectonics and historical seismicity of region surrounding the source;

2) a text named Notes that describes the source of the data used in the elaboration, decisions made in the selection of the input data and other relevant pieces of information.