On October 31 and November 1st, 2002, two earthquakes of magnitude 5.4 and 5.3 hit the area at the border between the Molise and Puglia regions in Southern Italy. The damage pattern qualified the quake as an intensity VII MCS, but with one notable exception: the village of San Giuliano di Puglia. The quake caused there a tragedy that was deeply felt all over Italy: the primary school collapsed, killing 27 pupils and 1 teacher, and injuring several others; two elder women died under the rubble of their houses. Since the first macroseismic survey it appeared clear that in S. Giuliano the intensity was two degrees higher with respect to three neighboring villages located within a radius of 3 km. Moreover, the damage pattern in S. Giuliano was divided in three zones areas with a different behavior. Soon after the quake our team started a campaign of microtremor HVSR measurements (Horizontal to Vertical Spectral Ratio), then we installed accelerometers and made damage and geological surveys . Finally we performed a geoelectrical tomography and two profiles of Vs velocity with depth using the NASW technique (Noise Analysis of Surface Waves). A house-by-house survey is still under way to determine if there is a vulnerability variation in different parts of the village. The acquired data are anyway sufficient to propose site amplification as a possible cause of the damage enhancement observed in S. Giuliano.
Quick survey of the possible causes of damage enhancement observed in San Giuliano after the 2002 Molise, Italy seismic sequence
CAPUTO, Riccardo;RIZZO, Enzo;
2003
Abstract
On October 31 and November 1st, 2002, two earthquakes of magnitude 5.4 and 5.3 hit the area at the border between the Molise and Puglia regions in Southern Italy. The damage pattern qualified the quake as an intensity VII MCS, but with one notable exception: the village of San Giuliano di Puglia. The quake caused there a tragedy that was deeply felt all over Italy: the primary school collapsed, killing 27 pupils and 1 teacher, and injuring several others; two elder women died under the rubble of their houses. Since the first macroseismic survey it appeared clear that in S. Giuliano the intensity was two degrees higher with respect to three neighboring villages located within a radius of 3 km. Moreover, the damage pattern in S. Giuliano was divided in three zones areas with a different behavior. Soon after the quake our team started a campaign of microtremor HVSR measurements (Horizontal to Vertical Spectral Ratio), then we installed accelerometers and made damage and geological surveys . Finally we performed a geoelectrical tomography and two profiles of Vs velocity with depth using the NASW technique (Noise Analysis of Surface Waves). A house-by-house survey is still under way to determine if there is a vulnerability variation in different parts of the village. The acquired data are anyway sufficient to propose site amplification as a possible cause of the damage enhancement observed in S. Giuliano.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
