GeoInt: the first macroseismic intensity database for the Republic of Georgia

Our work is intended to present the new macroseismic intensity database for the Republic of Georgia—hereby named GeoInt—which includes earthquakes from the historical (from 1250 B.C. onwards) to the instrumental era. Such database is composed of 111 selected earthquakes and related 3944 intensity data points (IDPs) for 1509 different localities, reported in the Medvedev-Sponheuer-Karnik scale (MSK). Regarding the earthquakes, the MS is in the 3.3–7 range and the depth is in the 2–36 km range. The entire set of IDPs is characterized by intensities ranging from 2–3 to 9–10 and covers an area spanning from 39.508° N to 45.043° N in a N-S direction and from 37.324° E to 48.500° E in an E-W direction, with some of the IDPs located outside the Georgian border, in the (i) Republic of Armenia, (ii) Russian Federation, (iii) Republic of Turkey, and (iv) Republic of Azerbaijan. We have revised each single IDP and have reevaluated and homogenized intensity values to the MSK scale. In particular, regarding the whole set of 3944 IDPs, 348 belong to the Historical era (pre-1900) and 3596 belong to the instrumental era (post-1900). With particular regard to the 3596 IDPs, 105 are brand new (3%), whereas the intensity values for 804 IDPs have been reevaluated (22%); for 2687 IDPs (75%), intensities have been confirmed from previous interpretations. We introduce this database as a key input for further improvements in seismic hazard modeling and seismic risk calculation for this region, based on macroseismic intensity; we report all the 111 earthquakes with available macroseismic information. The GeoInt database is also accessible online at http://www.enguriproject.unimib.it and will be kept updated in the future.