New empirical relationships between magnitude and distance for liquefaction

Historical research performed in the 1990s has updated previous compilations of liquefaction-induced phenomena that occurred during the last millenium in Italy. Liquefaction indications are reported in Italy for earthquakes with I-o > 5-6 (MCS) and M-s greater than or equal to 4.2, 90% of the cases falling within 50 km of the epicenter. The recently re-evaluated seismic parameters of the Italian historical earthquakes, together with the location of 317 indications of liquefaction features, provide a relatively complete database, permitting the author to highlight the distribution of intensity/magnitude values versus epicentral distance. In paleoseismic analyses these relationships may be considered a tool in evaluating the minimum energy of an earthquake that induced liquefaction features. (C) 2000 Elsevier Science B.V. All rights reserved.