Clues of postseismic relaxation for the 1915 Fucino earthquake (central Italy) from modeling of leveling data

We study five high precision leveling lines located around the epicentral area of 13 January 1915, Mw = 6.7 Fucino earthquake (Italy), that possibly recorded late stage
postseismic relaxation movements. The geodetic signal is expected to comprise both large-scale uplift of the Apennines and postseismic relaxation effects. In order to
verify this hypothesis and to estimate the amount of each contribution, we compute gravitational visco-elastic postseismic relaxation by inverting leveling data. Results indicate that the elastic upper crust is relatively thin (about 10 km) and post-seismic contribution could be set at 30% of the geodetic signal. Model parameters are consistent with previous knowledge of the 1915 Fucino earthquake source, local seismic hypocentral determinations and crustal models derived from surface waves.

Amoruso, A., L. Crescentini, and R. Scarpa (1998), Inversion of source
parameters from near- and far-field observations: An application to the
1915 Fucino earthquakes, central Apennines, Italy, J. Geophys. Res., 103,
29,989–29,999.
Aoudia, A., A. Borghi, R. Riva, R. Barzaghi, B. A. C. Ambrousius,
R. Sabadini, L. L. A. Vermeersen, and G. F. Panza (2003), Postseismic
deformation following the 1997 Umbria-Marche (Italy) moderate
normal faulting earthquakes, Geophys. Res. Lett., 30(7), 1390,
doi:10.1029/2002GL016339.
Arnadottir, T., P. Segall, and M. Matthews (1992), Resolving the discrepancy
between geodetic and seismic fault models for the 1989 Loma
Prieta, California, earthquake, Bull. Seismol. Soc. Am., 82, 2248– 2255.
Bartolini, C. (2003), Uplift and erosion: Driving processes and resulting
landforms, Ed. Quat. Int., 1, 101–102.
Boschi, E., E. Guidoboni, G. Ferrari, G. Valensise, and P. Gasperini (1997),
Catalogue of Strong Italian Earthquakes, 461 B.C. to 1990 [CD-ROM],
644 pp., Ist. Naz. di Geofis., Bologna, Italy.
Castello, B., M. Moro, C. Chiarabba, Di M. Bona, F. Doumaz, G. Selvaggi,
and A. Amato (2004), Revised magnitudes of relocated Italian earthquakes
catalogue (1981– 2002): A new seismicity map of Italy, paper
presented at XXII Congresso del Gruppo Nazionale di Geofisica della
Terra Solida, Rome, 14– 16 Dec.
Chiarabba, C., L. Jovane, and R. Di Stefano (2005), A new view of Italian
seismicity using 20 years of instrumental recordings, Tectonophysics,
395, 251– 268.
D’Agostino, N., J. A. Jackson, F. Dramis, and R. Funiciello (2001), Interactions
between mantle upwelling, drainage evolution and active normal
faulting: An example from the Central Apennines (Italy), Geophys. J.
Int., 147, 457– 497.
D’Anastasio, E. (2004), Analisi e integrazione di dati geodetici ed elementi
geologici per la definizione del campo di deformazione verticale a breve e
lungo termine in Appennino (Italia), Ph.D. thesis, 189 pp., Dip. di Fis.,
Univ. degli Studi di Bologna, Bologna, Italy.
Galadini, F., P. Messina, B. Giaccio, and A. Sposato (2003), Early uplift
history of the Abruzzi Apennines (central Italy): Available geomorphological
constraints, Quat. Int., 101–102, 125– 135.
Pollitz, F. F. (1997), Gravitational-viscoelastic postseismic relaxation on a
layered spherical Earth, J. Geophys. Res., 102, 17,921– 17,941.
Pollitz, F. F. (2003), VISCO1D v. 2 program package, U.S. Geol. Surv.,
Menlo Park, Calif. (Available at http://quake.wr.usgs.gov/research/
deformation/modeling/papers/2003/fred/)
Pollitz, F. F., G. Peltzer, and R. Burgmann (2000), Mobility of continental
mantle: Evidence from postseismic geodetic observations following the
1992 Landers earthquake, J. Geophys. Res., 105, 8035–8054.
Salvioni, G. (1957), I movimenti del suolo nell’Italia centro-settentrionale,
dati preliminari dedotti dalla comparazione di livellazioni, Boll. Geod. Sc.
Affini XVI, 3, 325– 366.
Ward, S. N., and G. Valensise (1989), Fault parameters and slip distribution
of the 1915 Avezzano, Italy, earthquake derived from geodetic observations,
Bull. Seismol. Soc. Am., 79, 690–710.