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The Campi Flegrei caldera is one of the highest risk\ud\ud volcanic areas on the Earth. Our research documents a\ud\ud 150 year-long period of intense volcanism following less\ud\ud than 200 years of repose after the Agnano-Monte Spina\ud\ud Plinian eruption (4.1 ka). The new data show that the\ud\ud renewal of volcanism was preceded by an uplift of a few\ud\ud tens of meters, triggered by mafic refilling of reservoirs at\ud\ud depths of 3 km or less. Our studies also indicate for the first\ud\ud time the occurrence of contemporaneous eruptions from\ud\ud at locations in different sectors of the caldera. These results\ud\ud suggest that a future eruptive crisis will likely be preceded\ud\ud by several meters of caldera-wide uplift in response to\ud\ud magma movements at depth. The trend of uplift of the\ud\ud caldera since 1969 may thus represent the unrest expected\ud\ud before a renewal of volcanism within an interval of decades\ud\ud to centuries. Citation: Isaia, R., P. Marianelli, and A. Sbrana\ud\ud (2009), Caldera unrest prior to intense volcanism in Campi\ud\ud Flegrei (Italy) at 4.0 ka B.P.: Implications for caldera dynamics\ud\ud and future eruptive scenarios, Geophys. Res. Lett., 36, L21303

During the 1944 eruption of Vesuvius a sudden change occurred in the dynamics of the eruptive events, linked to variations in magma composition. Kphonotephritic magmas were erupted during the effusive phase and the first lava fountain, whereas the emission of strongly porphyritic K-tephrites took place during the more intense fountain. Melt inclusion compositions (major and volatile elements) highlight that the magmas feeding the eruption underwent differentiation at different pressures. The K-tephritic volatile-rich melts (up to 3 wt.% H 2 O, 3000 ppm CO 2 , and 0.55 wt.% Cl) evolved to reach K-phonotephritic compositions by crystallization of diopside and forsteritic olivine at total fluid pressure higher than 300 MPa. These magmas fed a very shallow reservoir. The lowpressure differentiation of the volatile-poor K-phonotephritic magmas (H 2 O~1 wt.%) involved mixing, open-system degassing, and crystallization of leucite, salite, and plagioclase. The eruption was triggered by intrusion of a volatile-rich magma batch that rose from a depth of 11-22 km into the shallow magma chamber. The first phase of the eruption represents the partial emptying of the shallow reservoir, the top of which is within the volcanic edifice. The newly arrived magma mixed with that resident in the shallow reservoir and forced the transition from the effusive to the lava fountain phase of the eruption.

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A supereruption that occurred in the Campi Flegrei area, Italy, ca. 39 ka had regionaland global-scale environmental impacts and deposited the Campanian Ignimbrite (CI). We attempt to shed light on critical aspects of the eruption (depth of magma chamber, intensive pre-eruptive magma conditions) and the large-volume magma plumbing system on the basis of information derived from analyzing melt inclusion (MI) data. To achieve these aims, we provide new measurements of homogenization temperatures and values of dissolved H 2 O within phenocryst-hosted MIs from pumices erupted during different phases of the CI eruption. The MI data indicate that a relatively homogeneous overheated trachytic magma resided within a relatively deep magma chamber. Dissolved water contents in MIs indicate that prior to the eruption the magma chamber underwent radical changes related to differential upward movement of magma. Decompression of the rising trachytic magma caused a decrease in water solubility and crystallization, and trachytic bodies were emplaced at very shallow depths. The proposed eruptive model links portions of the main magma chamber and apophyses with specific eruptive units.

A volcanological map of the active Ischia volcanic field that includes Vivara Island is presented. The volcanological map is at the 1:10,000 scale and is based on 1:5000 field mapping, geological CAR.G data, and new volcanological studies. Geological data are represented on the threedimensional orographic background digital terrain model of the inland and offshore areas of the volcanic field. This allows a better visualization of the main morphological, volcanic, and geological structures. Six phases were identified on the basis of volcanotectonic events; the 110 volcanic units were arranged following these evolutive phases, and a volcanosedimentary apron unit was introduced. This volcanological map enables visualization of the volcanic evolution of the Ischia volcanic field and could be useful for the evaluation of volcano-related hazards in the area.

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