Caldera unrest prior to intense volcanism in Campi Flegrei (Italy) at 4.0 ka BP: Implications for caldera dynamics and future eruptive scenarios

The Campi Flegrei caldera is one of the highest risk volcanic areas on the Earth. Our research documents a 150 year-long period of intense volcanism following less than 200 years of repose after the Agnano-Monte Spina Plinian eruption (4.1 ka). The new data show that the renewal of volcanism was preceded by an uplift of a few tens of meters, triggered by mafic refilling of reservoirs at depths of 3 km or less. Our studies also indicate for the first time the occurrence of contemporaneous eruptions from at locations in different sectors of the caldera. These results suggest that a future eruptive crisis will likely be preceded by several meters of caldera-wide uplift in response to magma movements at depth. The trend of uplift of the caldera since 1969 may thus represent the unrest expected before a renewal of volcanism within an interval of decades to centuries. Citation: Isaia, R., P. Marianelli, and A. Sbrana (2009), Caldera unrest prior to intense volcanism in Campi Flegrei (Italy) at 4.0 ka B. P.: Implications for caldera dynamics and future eruptive scenarios, Geophys. Res. Lett., 36, L21303, doi: 10.1029/2009GL040513.