The use of IFSAR and classical geodetic techniques for caldera unrest episodes: application to the Campi Flegrei uplift event of 2000

Campi Flegrei caldera has a long history of large surface deformation,with isplacements of several meters in the 1970s and early 1980s. Its location within a densely populated urban area underscores the importance of understanding the relationship between large and episodic deformation events and their source mechanisms. The primary observable of the caldera’s activity is its surface deformation. Classical geodetic approaches such as leveling, have been complemented by the more advanced measurements of the Global Positioning System (GPS) and Synthetic Aperture Radar (SAR) interferometry. In this work we focus on the Campi Flegrei caldera uplift event that occurred from early spring to late summer 2000. Our goal is to highlight the potential to integrate interferometric SAR (IFSAR),GPS, and classical leveling data for ground deformation studies and source modeling. We compare models for the deformation source constrained by inversion of the differential IFSAR data (DIFSAR) with the model’s prediction for the GPS and leveling data. Resolution of possible changes in the source mechanism for Campi Flegrei caldera are limited by differences in the temporal,spatial and deformation component strengths of each data set. In the future,overcoming these data deficiencies will be important for resolving the dynamics of volcano systems and for volcanic hazard mitigation.

Achilli, V., Aquino, I., Berardino, P., Borgstrom, S., Cecere, G., Del Gaudio, C., De Martino, P., Fabris, M., Fusco, A.,Galluzzo, D., Lanari, R., Menin, A., Ricciardi, G.P., Ricco, C., Salemi, G., Sansosti, E., Sepe, V., Siniscalchi, V., Tesauro, M., 2001. Integration of SAR interferometry with classical geodetic techniques for ground deformation monitoring
at the Phlegrean Fields (Naples,Italy). Proceedings of the Italy^Canada Workshop on ‘3D Digital Imaging and Modeling Applications of: Heritage, Industry , Medicine and Land’,April 3^4, 2001, Padua.
Amelung, F., Jonsson, S., Zebker, H., Segall, P., 2000. Widespread uplift and ‘trapdoor’ faulting on Galapagos volcanoes observed with radar interferometry. Nature 407,993^996.
Avallone, A.,Zollo, A.,Briole, P., Delacourt, C., Beauducel, F., 1999. Subsidence of Campi Flegrei (Italy) detected by SAR interferometry. Geophys. Res. Lett. 26,2303^2306.
Berardino,P., Fornaro, G., Lanari, R., Sansosti, E., 2002.A new algorithm for surface deformation monitoring based on small baseline differential SAR interferograms. IEEE Trans. Geosci. Rem. Sens. 40,2375^2383.
Beutler, G., Bock, H., Brockmann, E., Dach, R., Fridez, P., Gurtner, W., Hugentobler, U., Ineichen, D., Johnson, J., Meindl, M., Mervart, L., Rotacher, M., Schaer, S., Springer, T., Weber, R., 2001. Bernese GPS Software Version 4.2. AIUB,University of Berne.
Bianchi, R., Coradini, A., Federico, C.,Giberti, G., Lanciano, P., Pozzi, J.P., Sartoris, G., Scandone, R., 1987. Modeling of surface deformation in volcanic areas: The 1970^1972 and 1982^1984 crises of Campi Flegrei,Italy. J. Geophys. Res. 92, 14139^14150.
Bonafede,M., 1993. Hot fuid migration - an effcient source of ground deformation - application to the 1982^1985 crisis at Campi Flegrei ^ Italy. J. Volcanol. geotherm. Res. 48, 187^198.
Bonafede,M., Mazzanti,M.,1998. Modelling gravity variations consistent with ground deformation in the Campi Flegrei caldera (Italy). J. Volcanol. Geotherm. Res. 81,137^157.
Delacourt,C., Briole, P., Achache, J., 1998. Tropospheric corrections of SAR interferograms with strong topography. Application to Etna. Geophys. Res. Lett. 25,2849^2852.
De Natale, G., Pingue, F., 1993. Ground deformations in collapsed caldera structures. J. Volcanol. Geotherm. Res. 57, 19^38.
De Natale,G.,Petrazzuoli,S.M.,Pingue, F.,1997. The effect of collapse structures on ground deformation in calderas. Geophys. Res. Lett. 24,1555^1558.
Di Vito,M.A., Isaia, R.,Orsi, G., Southon, J., de Vita,S., D’Antonio,M., Pappalardo, L., Piochi, M., 1999. Volcanism and deformation since 12,000 years at the Campi Flegrei caldera (Italy). J. Volcanol. Geotherm. Res. 91,221^246.
Dvorak,J.J., Berrino, G., 1991. Recent ground movement and seismic activity in Campi Flegrei,southern Italy: Episodic growth of a resurgent dome. J. Geophys. Res. 96,2309^2323.
Dvorak,J.J., Dzurisin,D.,1997. Volcano geodesy: The search for magma reservoirs and the formation of eruptive events. Rev. Geophys. 35,343^384.
Dvorak,J.J.,Gaspari ni, P., 1991. History of earthquakes and vertical ground movement in Campi Flegrei caldera,southern Italy: Comparison of precursory events to the AD 1538 eruption of Monte Nuovo and of activity since 1968. J. Volcanol. Geotherm. Res. 48,77^92.
Ferrucci,F.,Hirn, A., De Natale, G., Virieux, J., Mirabile, L., 1992. P^SV conversions at a shallow boundary beneath Campi Flegrei caldera (Italy): Evidence for the magma chamber. J. Geophys. Res. 97,15351^15359 .
Gaeta,F.S., De Natale, G., Peluso, F., Mastrolorenzo, G., Castagnolo,D., Troise, C.,Pingue, F., Mita, D.G., Rossano, S., 1998. Genesis and evolution of unrest episodes at Campi Flegrei caldera: The role of thermal fluid-dynamical processes in the geothermal system. J. Geophys. Res. 103, 20921^20933.
Lu,Z.,Mann, D., Freymueller,J.,1998. Satellite radar interferometry measures deformation at Okmok volcano. Eos, Trans. Am. Geophys. Union 79,461^468.
Lundgren, P.,Usai,S.,Sansosti,E.,Lanari,R., Tesauro, M., Fornaro,G.,Berardino, P.,2001. Modeling surface deformation observed with synthetic aperture radar interferometry at Campi Flegrei caldera. J. Geophys. Res. 106, 19355^19366.
Massonnet,D.,Rossi, M.,Carmona, C.,Ardagna, F.,Peltzer, G.,Feigl, K.,Rabaute, T., 1993. The displacement field of the Landers earthquake mapped by radar interferometry. Nature 364,138^142.
Mogi,K., 1958. Relations of the eruptions of various volcanoes and the deformation of the ground surface around them. Bull. Earth. Res. Inst. Tokyo Univ. 36,99^134.
Okada,Y., 1985. Surface deformation due to shear and tensile faults in a half-space. Bull. Seismol. Soc. Am. 75,1135^1154.
Orsi,G.,De Vita,S.,di Vito,M.,1996. The restless,resurgent Campi Flegrei nested caldera (Italy): Constraints on its evolution and configuration. J. Volcanol. Geotherm. Res. 74, 179^214.
Orsi,G., Civetta,L.,Del Gaudio,C., de Vita, S., di Vito, M.A., Isaia, R., Petrazzuo li, S. M., Ricciardi, G.P., Ricco, C., 1999a. Short term ground deformations and seismicity in the resurgent Campi Flegrei caldera (Italy): An example of active block-resurgence in a densely populated area. J. Volcanl. Geotherm. Res. 91,415^451.
Orsi,G.,Petrazzuoli, S.M.,Wohletz,K.,1999b. Mechanical and thermo-fuid behaviour during unrest at the Campi Flegrei caldera (Italy). J. Volcanl. Geotherm. Res. 91,453^470.
Osservatorio Vesuviano,2000. Crisi bradisismica della Caldera dei Campi Flegrei 2000. Osservatorio Vesuviano, Internal Report.
Yang,X.-M.,Davis, P.,Dieterich , J.H., 1988. Deformation from inflation of a dipping finite prolate spheroid in an elastic half-space as a model for volcanic stressing. J. Geophys. Res. 93,4249^5257.
Williams,C.A.,Wadge,G.,2000. An accurate and efficient method for including the effects of topography in three-dimensional elastic models of ground deformation with applications to radar interferometry. J. Geophys. Res. 105,8103^8120.