Abstract
During the summer of 1982 a continuous uplift began at Phlegraean Fields, an active volcanic area in southern Italy (Fig. 1), that persisted up to September 1984. The uplift, which reached a maximum value of about 160 cm in the central part of the Phlegraean caldera, was characterized by variable velocity and occurred within an area that extended about 7 km outward from the town of Pozzuoli (Fig. 1); the surface deformation performs a bell-shape pattern.
The uplift was accompanied by horizontal displacements and gravity changes that closely correlate with the described elevation changes.
The horizontal displacements displayed an anomalous pattern within a narrow belt about 1 km from the center of the uplift and approximately coincident with the area of maximum seismic activity. The change in gravity is attributed primarily to a free-air effect to which a small Bouguer effect must be added.
Several models have been invoked in order to explain the observed phenomenon. The one which gives the best fit to the observed data is an increasing pressure source of radial simmetry, at a constant depth of about 3 km beneath the town of Pozzuoli, and having a diameter of several hundred meters. Migration of magma at depth is believed to be responsible for the observed activity in the Phlegraean Fields caldera.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Armienti, P., Barberi, F., Bizouard, H., Clochiati, R., Innocenti, F., Metrich, N., Rosi, M. andSbrana, A., 1983,The Phlegraean Fields: Magma Evolution within a Shallow Chamber. In:Sheridan, M.F. andBarberi F. (Eds.),Explosive Volcanism. Jour. Volc. Geoth. Res.,17, p. 289–311.
Barbarella, M., Gubellini, A. andRusso, P., 1983,Rilievo ed analisi dei più recenti movimenti orizzontali del suolo nell'area flegrea. 2nd National Meeting of C.N.R., Gruppo Nazionale di Geofisica della Terra Solida, Roma, December 12–14, 1983.
Barberi, F., Corrado, G., Innocenti, F., Luongo, G.,Phlegraean Fields 1982–1984: Brief Chronicle of a Volcano Emergency in a Densely Populated Area. Bull. Volcanol. this issue.
--,Iannaccone, G., Innocenti, F., Luongo, G., Nunziata, C., Pascale, G. andRapolla A., 1980,The Evaluation of a Geothermal Model for the Neapolitan Volcanic Area. CEE Seminar on: «Geothermal Energy», Strasburg, 4–6 March.
Berrino, G., 1980,Comportamento dinamico dell'area flegrea. Degree Thesys, Faculty of Science, University of Naples (Italy).
--, 1984,Misure distanziometriche alla Solfatara di Pozzuoli-Campi Flegrei (Giugno 83-Settembre 84). Internal Report, Osservatorio Vesuviano — Gruppo Nazionale per la Vulcanologia CNR.
Bichara, M., Erling, J.C. andLakshmanan, J., 1981, Tecnique de misure et d'interpretation minimisant les erreurs de mesures en microgravimetric. Geoph. Prosp.,29, p. 782–279.
Cannizzo, L., Cerutti G. andMarson, I., 1978,Absolute-gravity Measurements in Europe. Il Nuovo Cimento,1C, n. 1, p. 39–86.
Carrara, E., Corrado, G., Nunziata, C., Pascale, G., Rapolla, A. andRoberti, N., 1981,Indagini geofisiche nell'area geotermale dei Campi Flegrei (Napoli). II Seminar of Progetto Finalizzato Energetica, C.N.R., subproject «Energia Geotermica», Rome, 16–19 June.
Corrado, G., Guerra, I., Lo Bascio, A., Luongo, G. andRampoldi, R., 1976/77,Inflation and Microearthquake Activity of Phlegraean Fields, Italy. Bull. Volcanol.,40–3, p. 169–188.
--,Grimaldi, M., Lo Bascio, A., andLuongo, G., 1980,Ground Deformations in the Phlegraean Fields Volcanic Area, Italy. Proc. of 17th Assembly of the ESC, Budapest.
——, 1981,Ground Deformation Measurements in Active Volcanic Areas Using Tide Gauge. Bull. Volcanol.,44-3, p. 505–511.
Dequal, S., 1972, Rilievo degli spostamenti planimetrici di punti nella zona di Pozzuoli. In:Relazione sui rilievi effettuati nell'area flegrea nel 1970–71. Quad. Ric. Scient.,83, C.N.R., p. 231–262.
Ducarme, B., Poiteven, C. andLoodts, J., 1978,Precise Tidal Corrections for High Precision Gravity Measurements. 8th Meeting of the International Gravity Commission, Paris, 12–16 September.
Finetti, I., andMorelli, C., 1974, Esplorazione sismica a riflessione nei Golfi di Napoli e Pozzuoli. Boll. Geof. Teor. Appl.,16, p. 175–222.
Hagiwara, Y., 1977,Gravity Changes Associated with Seismic Activity. In:Earthquake Precursor (Kisslinger, C. andSuzuki, Z., eds.). AEPS,2, p. 137–146.
Hirne, A. andFerrucci, F., 1984,Spatial Anomaly of P and S Waves Velocities Above the Seismically Active Zone at Campi Flegrei (Pozzuoli, Italy). Internal Report, Institut de Physic du Globe, Paris.
Iannaccone, G., Lo Bascio, A., Luongo, G. andScarpa, R., 1979,Indagini di sismica passiva nell'area dei Campi Flegrei. I Seminar of Progetto Finalizzato Energetica, C.N.R., subproject « Energia Geotermica », Rome, December 18–21.
Johnson, A.M., 1970,Physical Process in Geology. Freeman, Cooper & Company, 577 pp. (p. 60–65).
——, andPollard, D.D., 1973,Mechanics of Growth of Some Laccolithic Intrusion in the Henry Mountains, Utah, I. Field Observation, Gilbert's Model, Physical Properties and Flow of the Magma. Tectonophysics,18, p. 261–309.
La Torre, P. andNannini, R., 1980,Geothermal Well Location in Southern Italy: the Contribution of Geophysical Methods. Boll. Geof. Teor. Appl.,SSII-87, p. 201–209.
Longman, I.M., 1959,Formulas for Computing the Tidal Acceleration Due to the Moon and the Sun. Journ. Geoph. Res.,64, n. 12, p. 2351–2355.
Maino, A., Segre, G. andTribalto, G., 1964, Rilevamento gravimetrico dei Campi Flegrei e dell'isola di Ischia. Ann. Osserv. Vesuv., serie VI,5, p. 227–312.
Manzoni, G., 1972, Misure clinometriche. In:Relazioni sui rilievi effettuati nell'area flegrea nel 1970–71. Quad. Ric. Scient.,83, C.N.R., p. 198–208.
Marson, I., andMorelli, C., 1978,First Order Gravity Net in Italy. Boll. Geod. e Scienze Affini, anno XXXVII,4, p. 659–689.
McConnel, R.K. andGantar, C., 1974,Adjustment and Analysis of Data for IGSN71, Appendix 4. IAG Spec. Publ.,4, p. 165–190, Int. Ass. of Geod., Paris.
Mogi, K., 1958,Relation Between the Eruptions of Various Volcanoes and the Deformations of the Ground Surface Around Them. Bull. Earth. Res. Inst.,36, p. 99–134.
Oliveri Del Castillo, A., 1960,Studio del bradisisma flegreo mediante osservazioni mareografiche. X Meeting of Italian Gephysical Society, Rome, November 18–19.
Osservatorio Vesuviano, 1984,Bradisismo Flegreo. Rapporto Sorveglianza Gennaio 1982 — Gennaio 1984. Internal Report.
Parascandola, A., 1947,I fenomeni bradisismici del Serapeo di Pozzuoli. Genovese, Napoli.
Pollard, D.D. andJohnson, A.M., 1973,Mechanics of Growth of Some Laccolithic Intrusions in the Henry Mountains, Utah, II. Bending and Failure of Overburden Layers and Sill Formation. Tectonophysics,18, p. 311–354.
Principe, C., Rosi, M., Santacroce, R. andSbrana, A., 1982,Workshop on Explosive Volcanism. Guidebook of the field excursion to Phlegraean Fields and Vesuvius. C.N.R., Italy N.F.S., U.S.A.
Rampoldi, R., 1972, Risultati delle osservazioni sismografiche effettuate dal giugno 1970 al luglio 1971. Quad. Ric. Scient.,83, C.N.R., p. 187–197.
Rosi, M., Sbrana, A. andPrincipe, C., 1983,The Phlegraean Fields: Structural Evolution, Volcanic History and Eruptive Mechanism. In:Sheridan, M.F. andBarberi, F. (Eds.),Explosive Volcanism. J. Volc. Geoth. Res.,17, p. 273–288.
Tryggvason, E., 1981,Pressure Variations and Volume of the Krafla Magma Reservoir. Nordic Volcanol. Inst.,8105, Univ. Iceland, Reykjavik.
Ulrych, T.J., Smylie, D.E., Jensen, O.G. andClarke, G.K.C., 1973,Predictive Filtering and Smoothing of Short Records by Using Maximum Entropy. Journ. Geoph. Res.,78, p. 4959–4964.
Walsh, 1975,An Analysis of Local Changes in Gravity Due to Deformation. Pageoph.,113, p. 97–106.
Walsh, J.B. andRice, J.R., 1979,Local Changes in Gravity Resulting from Deformation. Journ. Geoph. Res.,84, 131, p. 164–170.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Berrino, G., Corrado, G., Luongo, G. et al. Ground deformation and gravity changes accompanying the 1982 Pozzuoli uplift. Bull Volcanol 47, 187–200 (1984). https://doi.org/10.1007/BF01961548
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01961548