A source study of the 9 september 1998 (Mw 5.6) castelluccio earthquake in southern italy using teleseismic and strong motion data

• Published in: Natural hazards (Dordrecht) Vol. 37; no. 3; pp. 245 - 262
• Main Authors: ARRIGO, G, ROUMELIOTI, Z, BENETATOS, Ch, KIRATZI, A, BOTTARI, A, NERI, G, TERMINI, D, GORINI, A, MARCUCCI, S
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.03.2006; Springer Nature B.V
• Subjects: Earth sciences; Earth, ocean, space; Earthquakes; Earthquakes, seismology; Engineering and environment geology. Geothermics; Exact sciences and technology; Internal geophysics; Natural hazards: prediction, damages, etc; Seismic activity; Source studies; Southern Europe; Italy; stochastic methods; simulation; teleseismic waveform modeling; accelerograms; earthquakes; focal mechanisms; rupture; acceleration; nucleation; amplitude; tectonic maps; fault displacements; aftershocks; magnitude; stochastic processes; hypocenter; site effects; focal mechanism; strong ground motion; Southern Italy; models; seismotectonics; teleseismic signals; Europe; normal faults; mainshocks; body waves; strong motion; waveforms
• ISSN: 0921-030X; 1573-0840
• DOI: 10.1007/s11069-005-4644-1

Teleseismic and strong motion data are used to derive the source parameters of the September 9, 1998 Castelluccio earthquake (M5.6). Teleseismic body-wave modeling indicates normal faulting (Plane 1: strike = 328°, dip = 50°, rake = -75°; Plane 2: strike = 126°, dip = 42°, rake = -107°) along NW-SE striking planes. Both nodal planes of the computed focal mechanism are tested for their capability of reproducing the mainshock acceleration time histories at three strong motion stations. Synthetic accelerograms are estimated using the stochastic method for finite sources in combination with the H/V ratios technique for the incorporation of the site effect. Our preferred model, which provided the best fit between synthetic and observed waveforms and corresponding Fourier amplitude spectra, consists of a NE-dipping normal fault with dimensions 8 × 7 km. The rupture nucleation point, which is assumed to coincide with the hypocenter location, was confined to the southeasternmost, deepest part of the fault. Our results are in good agreement with the so far released information regarding the aftershock sequence of the examined event, as well as the general seismotectonic knowledge on the broader epicentral area.[PUBLICATION ABSTRACT]