Earth-prints repository, logo   DSpace

About DSpace Software
|earth-prints home page | roma library | bologna library | catania library | milano library | napoli library | palermo library
Please use this identifier to cite or link to this item:

Authors: Calderoni, G.*
Rovelli, A.*
Milana, G.*
Valensise, G.*
Title: Do Strike-Slip Faults of Molise, Central-Southern Italy, Really Release a High Stress?
Title of journal: Bulletin of the Seismological Society of America
Series/Report no.: /(2009)
Issue Date: 2009
DOI: 10.1785/0120090046
Keywords: Molise, stress drop
Abstract: The 31 October and 1 November 2002, Molise earthquakes (both MW 5.7) were caused by right-lateral slip between 12 and 20 km depth. These earthquakes are the result of large-scale reactivation of pre-existing, left-lateral, regionally extended E-W structures of Mesozoic age. Although recorded ground motions were generally smaller than expected for typical Italian earthquakes, a recent paper attributes a stress drop as high as 180 bars to the Molise earthquakes. We remark that a high stress drop is in contrast both with the relatively long source duration inferred in previous investigations and with geodetic evidence for a significantly smaller fault slip compared with other Apennines earthquakes having similarly large rupture area (e.g. 1997 Umbria-Marche earthquakes). We analyzed both ground acceleration spectra of the mainshocks and single-station spectral ratios of broad-band seismograms in an extended magnitude range (2.7 ≤ MW ≤ 5.7). Our results show that neither the spectral amplitudes of recorded ground motions nor the spectral ratios can be fit by a high stress drop source. Instead we find that the observations are consistent with a low stress drop, our best estimates ranging between 6 and 25 bars, in agreement with the relatively long source duration and small coseismic slip. We interpret the low stress of the 2002 Molise earthquakes in terms of lower energy release mechanisms due to the reutilization of faults reactivated opposite to their original sense of slip.
Appears in Collections:04.06.04. Ground motion
Papers Published / Papers in press

Files in This Item:

File Description SizeFormatVisibility
Calderoni_et_al_Sottomesso.doc269.5 kBMicrosoft WordView/Open
Fig1.pdfFigure 1.828.86 kBAdobe PDFView/Open
Fig2.pdfFigure 2284.29 kBAdobe PDFView/Open
Fig3.pdfFigure 31.26 MBAdobe PDFView/Open
Fig4.pdfFigura 4227.14 kBAdobe PDFView/Open
Fig5.pdfFigura 5429.67 kBAdobe PDFView/Open
Fig6.pdfFigure 6351.67 kBAdobe PDFView/Open
Fig7.pdfFigure 7463.26 kBAdobe PDFView/Open
Fig8.pdfFigure 8267.52 kBAdobe PDFView/Open
Fig9.pdfFigure 9404.39 kBAdobe PDFView/Open
Fig10.pdfFigure 106.42 MBAdobe PDFView/Open
FigA1.pdfFigure A1611.22 kBAdobe PDFView/Open
FigA2.pdfFigure A2940.84 kBAdobe PDFView/Open

This item is licensed under a Creative Commons License
Creative Commons

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Share this record




Stumble it!



Valid XHTML 1.0! ICT Support, development & maintenance are provided by CINECA. Powered on DSpace Software. CINECA