HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Pasolini, C. Articles by D’Amico, V. Search for Related Content GeoRef GeoRef Citation

The Attenuation of Seismic Intensity in Italy, Part I: Theoretical and Empirical Backgrounds

Dipartimento di Fisica, Università di Bologna, Viale Berti Pichat 8, I-40127 Bologna, Italy chiara.pasolini{at}gmail.com paolo.gasperini{at}unibo.it

D. Albarello

Dipartimento di Scienze della Terra, Università di Siena, Via Laterina 8, I-53100 Siena, Italy albarello{at}unisi.it

B. Lolli

Dipartimento di Fisica, Università di Bologna, Viale Berti Pichat 8, I-40127 Bologna, Italy barbara.lolli{at}unibo.it

V. D’Amico^*

Dipartimento di Scienze della Terra, Università di Siena, Via Laterina 8, I-53100 Siena, Italy

^* Present address: Istituto Nazionale di Geofisica e Vulcanologia, Via della Faggiola, 32, I-56126 Pisa, Italy; damico@pi.ingv.it.

We critically analyze the results on seismic intensity attenuation in Italy derived by Albarello and D’Amico (2004) and Gasperini (2001). We demonstrate that, due to the inadequacy of certain underlying assumptions, the empirical relationships determined in those studies did not best reproduce the decay of intensity as the distance from the source increases. We reconsidered some of the relevant concepts and assumptions used in these intensity-attenuation studies (macroseismic epicenter, epicentral intensity, data completeness) to suggest some useful recipes for obtaining unbiased estimates. In particular, we suggest that (1) data for distances from the source at which an intensity below the limit of diffuse perceptibility (IV) is expected should be excluded from attenuation computations because such data are clearly incomplete, (2) attenuation equations that include a term proportional to the epicentral intensity I₀ with a coefficient different from 1.0 must not be used because they imply a variable offset between I₀ and the intensity expected at the epicenter, and (3) epicentral intensities must be recomputed consistently with the attenuation equation because those reported by the Italian catalog do not generally correspond with the intensity predicted at the epicenter by the attenuation relationships so far proposed. Following these suggestions produces a significant reduction in the standard deviation of the model that might lead to a corresponding reduction of the estimates of seismic hazard.

This article has been cited by other articles:

				D. Stromeyer and G. Grunthal Attenuation Relationship of Macroseismic Intensities in Central Europe Bulletin of the Seismological Society of America, April 1, 2009; 99(2A): 554 - 565. [Abstract] [Full Text] [PDF]

				V. D'Amico and D. Albarello SASHA: A Computer Program to Assess Seismic Hazard from Intensity Data Seismological Research Letters, September 1, 2008; 79(5): 663 - 671. [Full Text] [PDF]

				C. Pasolini, D. Albarello, P. Gasperini, V. D'Amico, and B. Lolli The Attenuation of Seismic Intensity in Italy, Part II: Modeling and Validation Bulletin of the Seismological Society of America, April 1, 2008; 98(2): 692 - 708. [Abstract] [Full Text] [PDF]