Focal mechanisms of NE Italy and surroundings (1928-2008),

A collection of focal mechanisms, computed from earthquakes occurred in NE Italy and surroundings area during the last eighty years (1928-2008), is presented in this report. Focal mechanisms are the basic elements for seismotectonic investigation and for seismic hazard analysis. Nowadays on-line catalogues of fault plane solutions, computed by seismic moment tensor, are compiled by several agencies (e.g. Harvard CMT catalogue, SED catalogue, MedNet). The same agencies, for earthquakes with magnitude above 4.5, compute focal mechanisms in near real-time soon after the occurrence of earthquakes and spread immediately the solutions to the seismologists. However, for earthquakes occurred before the development of broad band digital seismology or for those events with magnitude in the range 3.5-4, the contribution given by first polarities mechanisms published in the literature, is still essential to seismological studies. Several catalogues of fault plane solutions have been compiled in the past, collecting solutions scattered over a large number of papers. Our catalogue, starting from a selection of data extracted from the EMMA catalogue (Vannucci and Gasperini, 2004) compiled for the Euro Mediterranean area, updates the above mentioned dataset for NE Italy and surroundings, and add new focal mechanisms more recently published in the literature up to July 2008. Our collection contains also still unpublished first polarities focal mechanisms computed by Gianni Bressan and Gianfranco Renner, who generously contributed to enrich this catalogue. Especially for unpublished solutions cited as personal communication, I recommend that users insert in their references the authors that originally computed the focal plane solutions.Although we did our best to check for publications and mistyping, some errors or involuntary omissions could be present in this catalogue. I will be grateful to all investigators who will help me in improving this dataset.