GNGTS 2016 - Atti del 35° Convegno Nazionale

GNGTS 2016 S essione 1.1 185 provides indications of limited interseismic locking. Most of the dextral shear between the Eastern Southern Alps and the Eastern Alps blocks is accommodated along the Fella-Sava fault rather than the Periadriatic fault. In northern Croatia and Slovenia geodetic and seismological data allow constraining the kinematics of the active structures bounding the triangular-shaped region encompassing the Sava folds, which plays a major role in accommodating the transition fromAdria- to Pannonian-like motion trends. The analysis of the seismic and geodetic moment rates provides new insights into the seismic potential along the ESA front. 6 May 1976 Friuli Earthquake: re-evaluation of macroseismic data, new map and comparison with old intensity estimates A. Tertulliani 1 , I. Cecic´ 2 , G. Grünthal 3 , D. Kaiser 4 , R. Meurers 5 , I. Sovic´ 6 J. Pazdirková 7 1 Istituto Nazionale di Geofisica e Vulcanologia (INGV), Rome, Italy 2 Agencija RS za okolje (ARSO) Ljubljana, Slovenia 3 GFZ German Research Centre for Geosciences, Potsdam, Germany 4 Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover, Germany 5 Zentralanstalt für Meteorologie und Geodynamik (ZAMG), Vienna, Austria 6 GZAM, Zagreb, Croatia 7 Institute of Physics of the Earth, Brno, Czech Republic Forty years after a devastating earthquake sequence, that has demanded almost 1000 lives and destroyed towns and villages in Friuli (northern Italy) and adjacent regions, a thorough interstate macroseismic field does not exist. We have then decided to take another look at the macroseismic data using the EMS-98 scale.Although four decades are not, historically speaking, a long period, and the quantity of existing data can be measured in hundred of kilograms of paper (questionnaires, damage analysis, newspapers, studies etc.) it was disturbing to find out that many of the original data are already missing and are probably lost forever. Furthermore, ‘70s were a period of great instrumental development, and the intensity data were unfortunately put away to the background of seismology, with the consequence of the dispersion of large amount of data. A team of macro-and-historical seismologists from different countries decided to fill this gap, taking on such a difficult task. Aim of this work is to joint the different data sets from the European countries where the earthquake was felt. Effort was put into finding additional and yet unknown primary data, e.g. photographic material of damaged localities and eyewitness’ reports. For IDPs with only low intensity values (especially in Switzerland, Hungary, Czech Republic, Poland) it was decided that the data will be included into the joint dataset without the EMS re-evaluation. For IDPs with higher intensity (especially in the countries closer to the epicentral region like Austria, Croatia, Germany – exWest and East part separately, Slovenia) the re-evaluation was performed. A particular and more complicated case concerns Italian data: the two main current Italian catalogues record two different data sets, both in IDPs number and in intensity values. Due to the methodological differences in a number of cases the EMS intensities are different than the previous MSK or MCS ones. The work is in progress, and new data from other countries will be soon recovered. The presentation will discuss the state of the art and the used methodology and data.