Report on Campi Flegrei (Italy) — January 1985

Scientific Event Alert Network Bulletin, vol. 10, no. 1 (January 1985)
Managing Editor: Lindsay McClelland.

Campi Flegrei (Italy) Seismicity declines; slight deflation

Please cite this report as:

Global Volcanism Program, 1985. Report on Campi Flegrei (Italy). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 10:1. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.SEAN198501-211010.

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Campi Flegrei

Italy

40.827°N, 14.139°E; summit elev. 458 m

All times are local (unless otherwise noted)


"A magnitude 3.8 earthquake occurred on 8 December and was located on the E side of Solfatara Crater. After this event, the seismic activity was very low during December and January. During December the tide gauges in the Gulf of Pozzuoli recorded no uplift of the ground in the area. In the second week of January, a slight deflation was measured by the Pozzuoli tide gauge. Only the radon contents of water in monitored wells showed an increase. In mid-November the values were similar to those in the corresponding period of December 1983-January 1984. We are waiting for a longer quiescence period before releasing a ceased alert warning."

Geologic Background. Campi Flegrei is a large 13-km-wide caldera on the outskirts of Naples that contains numerous phreatic tuff rings and pyroclastic cones. The caldera margins are poorly defined, and on the south lie beneath the Gulf of Pozzuoli. Episodes of dramatic uplift and subsidence within the dominantly trachytic caldera have occurred since Roman times. The earliest known eruptive products are dated 47,000 yrs BP. The caldera formed following two large explosive eruptions, the massive Campanian ignimbrite about 36,000 BP, and the >40 cu km Neapolitan Yellow Tuff (NYT) about 15,000 BP. Following eruption of the NYT a large number of eruptions have taken place from widely scattered subaerial and submarine vents. Most activity occurred during three intervals: 15,000-9500, 8600-8200, and 4800-3800 BP. Two eruptions have occurred in historical time, one in 1158 at Solfatara and the other in 1538 that formed the Monte Nuovo cinder cone.

Information Contacts: G. Luongo and R. Scandone, OV; F. Barberi, Univ. di Pisa.