Upcoming Workshops

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Caldera unrest driven by CO2-induced drying of the deep hydrothermal system

Interpreting volcanic unrest is a highly challenging and non-unique problem at calderas, since large hydrothermal systems may either hide or amplify the dynamics of buried magma(s). Here we use the exceptional ground displacement and geochemical datasets from the actively degassing Campi Flegrei caldera (Southern Italy) to show that ambiguities disappear when the thermal evolution of the deep hydrothermal system is accurately tracked. By using temperatures from the CO2-CH4 exchange of 13C and thermodynamic analysis of gas ascending in the crust, we demonstrate that after the last 1982-84 crisis the deep hydrothermal system evolved through supercritical conditions under the continuous isenthalpic inflow of hot CO2-rich gases released from the deep (~8 km) magma reservoir of regional size. This resulted in the drying of the base of the hot hydrothermal system, no more buffered along the liquid-vapour equilibrium, and excludes any shallow arrival of new magma, whose abundant steam degassing due to decompression would have restored liquid-vapour equilibrium. The consequent CO2-infiltration and progressive heating of the surrounding deforming rock volume cause the build-up of pore pressure in aquifers, and generate the striking temporal symmetry that characterizes the ongoing uplift and the post-1984 subsidence, both originated by the same but reversed deformation mechanism

The geothermal potential of Campanian volcanoes: evaluation and opportunities.

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On the Long Range Clustering of Global Seismicity and its Correlation With Solar Activity: A New Perspective for Earthquake Forecasting

Large earthquakes occurring worldwide have long been recognized to be non Poisson distributed, so involving some large scale correlation mechanism, which could be internal or external to the Earth. We have recently demonstrated this observation can be explained by the correlation of global seismicity with solar activity. We inferred such a clear correlation, highly statistically significant, analyzing the ISI-GEM catalog 1996–2016, as compared to the Solar and Heliospheric Observatory satellite data, reporting proton density and proton velocity in the same period. However, some questions could arise that the internal correlation of global seismicity could be mainly due to local earthquake clustering, which is a well-recognized process depending on physical mechanisms of local stress transfer. We then apply, to the ISI-GEM catalog, a simple and appropriate de-clustering procedure, meant to recognize and eliminate local clustering. As a result, we again obtain a non poissonian, internally correlated catalog, which shows the same, high level correlation with the proton density linked to solar activity. We can hence confirm that global seismicity contains a long-range correlation, not linked to local clustering processes, which is clearly linked to solar activity. Once we explain in some details the proposed mechanism for such correlation, we also give insight on how such mechanism could be used, in a near future, to help in earthquake forecasting

Tectonic stress and renewed uplift at Campi Flegrei caldera, southern Italy: New insights from caldera drilling

Deep drilling is a key tool for the investigation of active volcanoes in the modern Earth Sciences, as this provides the only means to obtain direct information on processes that occur at depth. Data acquired from drilling projects are fundamental to our understanding of volcano dynamics, and for mitigation of the hazards they pose for millions of people who live close to active volcanoes. We present here the first borehole measurement of the stress field in the crust of Campi Flegrei (southern Italy), a large active caldera, and one of the highest risk volcanoes worldwide. Measurements were performed to depths of ∼500 m during a pilot study for the Campi Flegrei Deep Drilling Project. These data indicate an extensional stress field, with a minimum horizontal stress of ca. 75% to 80% of the maximum horizontal stress, which is approximately equal to the vertical stress. The deviation from lithostatic conditions is consistent with a progressive increase in applied horizontal stress during episodes of unrest, since at least 1969. As the stress field is evolving with time, the outcome of renewed unrest cannot be assessed by analogy with previous episodes. Interpretations of future unrest must therefore accommodate the possibility that Campi Flegrei is approaching conditions that are more favourable to a volcanic eruption than has previously been the case. Such long-term accumulation of stress is not expected to be unique to Campi Flegrei, and so might provide a basis for improved forecasts of eruptions at large calderas elsewhere

Volcanic hazard assessment at the Campi Flegrei caldera

Previous and new results from probabilistic approaches based on available volcanological data from real eruptions of Campi Flegrei, are assembled in a comprehensive assessment of volcanic hazards at the Campi Flegrei caldera, in order to compare the volcanic hazards related to the different types of events. Hazard maps based on a very wide set of numerical simulations, produced using field and laboratory data as input parameters relative to the whole range of fallout and pyroclastic-flow events and their relative occurrence, are presented. The results allow us to quantitatively evaluate and compare the hazard related to pyroclastic fallout and density currents (PDCs) in the Campi Flegrei area and its surroundings, including the city of Naples. Due to the dominant wind directions, the hazard from fallout mostly affects the area east of the caldera, and the caldera itself, with the level of probability and expected thickness decreasing with distance from the caldera and outside the eastern sectors. The hazard from PDCs decrease roughly radially with distance from the caldera centre and is strongly controlled by the topographic relief, which produces an effective barrier to propagation of PDCs to the east and northeast, areas which include metropolitan Naples. The main result is that the metropolitan area of Naples would be directly exposed to both fallout and PDCs. Moreover, the level of probability for critical tephra accumulation by fallout is relatively high, even for moderate-scale events, while, due to the presence of topographic barriers, the hazard from PDCs is only moderate and mostly associated with the largest events

Effectiveness of high dose sublingual immunotherapy to induce a stepdown of seasonal asthma: a pilot study

There is ample evidence to support the efficacy of sublingual immunotherapy (SLIT) on allergic rhinitis, while there is less solid data regarding asthma. We evaluated the effects of a high dose birch SLIT on birch-induced rhinitis and asthma in a controlled study