Assessing future vent opening locations at the Somma-Vesuvio volcanic complex. 2, probability maps of the caldera for a future Plinian/sub-Plinian event with uncertainty quantification

In this study, we combine reconstructions of volcanological data sets and inputs from a structured expert judgment to produce a first long-term probability map for vent opening location for the next Plinian or sub-Plinian eruption of Somma-Vesuvio. In the past, the volcano has exhibited significant spatial variability in vent location; this can exert a significant control on where hazards materialize (particularly of pyroclastic density currents). The new vent opening probability mapping has been performed through (i) development of spatial probability density maps with Gaussian kernel functions for different data sets and (ii) weighted linear combination of these spatial density maps. The epistemic uncertainties affecting these data sets were quantified explicitly with expert judgments and implemented following a doubly stochastic approach. Various elicitation pooling metrics and subgroupings of experts and target questions were tested to evaluate the robustness of outcomes. Our findings indicate that (a) Somma-Vesuvio vent opening probabilities are distributed inside the whole caldera, with a peak corresponding to the area of the present crater, but with more than 50% probability that the next vent could open elsewhere within the caldera; (b) there is a mean probability of about 30% that the next vent will open west of the present edifice; (c) there is a mean probability of about 9.5% that the next medium-large eruption will enlarge the present Somma-Vesuvio caldera, and (d) there is a nonnegligible probability (mean value of 6–10%) that the next Plinian or sub-Plinian eruption will have its initial vent opening outside the present Somma-Vesuvio caldera

Externalities and the nucleolus

In most economic applications, externalities prevail: the worth of a coalition depends on how the other players are organized. We show that there is a unique natural way of extending the nucleolus from (coalitional) games without externalities to games with externalities. This is in contrast to the Shapley value and the core for which many different extensions have been proposed

The beam and detector of the NA62 experiment at CERN

NA62 is a fixed-target experiment at the CERN SPS dedicated to measurements of rare kaon decays. Such measurements, like the branching fraction of the K+ → π+ ν bar nu decay, have the potential to bring significant insights into new physics processes when comparison is made with precise theoretical predictions. For this purpose, innovative techniques have been developed, in particular, in the domain of low-mass tracking devices. Detector construction spanned several years from 2009 to 2014. The collaboration started detector commissioning in 2014 and will collect data until the end of 2018. The beam line and detector components are described together with their early performance obtained from 2014 and 2015 data

Vegetation changes during the late Early Pleistocene at Montalbano Jonico (Province of Matera, southern Italy) based on pollen analysis

International audiencePollen analysis of the Early Pleistocene Montalbano Jonico section in southern Italy reveals cyclic changes driven by climate and eustasy, as illustrated by mesothermic vs. steppe elements for climate, and Pinus vs. Caryophyllaceae, Amaranthaceae–Chenopodiaceae and Ephedra for eustasy. These results are directly compared with oxygen isotope data on Globigerina bulloides constrained within a biostratigraphic framework based on nannofossils and foraminifers, facilitating a new age calibration for the section. Marine isotopic stages 37 to 23 (1.250–0.900 Ma) are recorded, and compared with global and Mediterranean oxygen isotope curves. High-frequency changes in pollen are related to the Mediterranean curve (Globigerinoides ruber) from ODP Site 967, and superimposed the LR04 stack curve. During the Early Pleistocene, pollen recorded global and regional climate changes related to obliquity and precession, respectively, and regional tectonic evolution. Precession forcing was caused by Mediterranean wetness related to precession. The intensified precession effect over climatic cycles, that is expected during the Middle Pleistocene Transition, is not recorded in the Montalbano Jonico interval A vegetation changes

Carta Geologica d'Italia Foglio 536 Ugento

La monografia contiene le note illustrative, dove sono stati descritti in dettaglio i principali caratteri stratigrafici e strutturali dell'area compresa nel foglio 536 Ugento e la carta geologica dello stesso fogli

Vegetation and climate across the EarlyeMiddle Pleistocene transition at Montalbano Jonico, southern Italy

Pollen analysis of the Montalbano Jonico marine succession (MJS), southern Italy, provides a continuous vegetational record between 858 ka and 745.13 ka which includes Marine Isotope Stage (MIS) 19, now considered the closest orbital analogue to the Holocene. A comparison between paleoclimate proxies and global signals of past climate change allows the pollen record to be interpreted in terms of major environmental and climate modifications through MIS 21e18 at the orbital- and sub-orbital-scale. This is also central to understanding migration patterns of the genus Homo. Interglacials are expressed by the dominance of a mesophilic vegetation typical of a (warm) temperate and relatively humid climate. Deciduous Quercus dominated fully temperate arboreal forest already devoid of subtropical taxa. Wooded steppes to steppes expanded during glacials when cold and dry conditions prevailed. At MJS the main expansion of temperate forest, dominated by broad-leaved trees, correlates to MIS 19.3, whereas the expansion of steppe vegetation, during drier conditions, marks MIS 19.2 directly above the volcaniclastic layer V4, dated at 773.9 ± 1.3 ka. More intensively arid conditions developed during MIS 20 and MIS 18; the Pollen Temperature Index reaches its minimum in uppermost MIS 20 in agreement with a significant cold and arid climate phase of wide significance in the North Hemisphere, as documented by prominent peaks in North Atlantic ice rafted debris (IRD) and Mediterranean aeolian dust records. On the other hand, Artemisia, a significant component of steppes, shows its maximum expansion during earlier phases of MIS 18. Millennial to sub-millenial-scale climate variability is evidenced by two abrupt shortterm pollen events within MIS 19.3, which show a dominant increase of the cosmopolitan herbaceous component at around 783.54 ka and 774.84 ka, respectively. The vegetational and inferred climate changes for MIS 19 offer two possibilities: (1) to investigate the interglacial climate variability and discuss the linkage between climate and changes in geomagnetic field intensity close to the Matuyama eBrunhes paleomagnetic boundary (MBB), and (2) to help evaluate the role of the MBB in defining the Middle Pleistocene global boundary stratotype section and point (GSSP). With respect to point 2, a comparison of data at MJS with the pollen record at the nearby and coeval Valle di Manche section is relevant and evidences the complex response of vegetation to climate events possibly under the effects of both astronomical and local factors

CALCAREOUS NANNOFOSSIL EVENTS IN THE LOWER-MIDDLE PLEISTOCENE TRANSITION AT THE MONTALBANO JONICO SECTION AND ODP SITE 964: CALIBRATION WITH ISOTOPE AND SAPROPEL STRATIGRAPHY

We present quantitative data on calcareous nannofossil biostratigraphy in the section of Montalbano Jonico (Southern Italy). This is one of the candidate Global Statotype Section and Point (GSSP) of the Middle Pleistocene. The first common occurrence (FCO) and last common occurrence (LCO) of Reticulofenestra asanoi are well detectable in the section and are here proposed as additional events for improving biostratigraphic resolution in the interval corresponding to the transition between the small Gephyrocapsa Zone and Pseudoemiliania lacunosa Zone. The potential value of the bioevents is tested in a Mediterranean deep-sea core of ODP Site 964, located in the Ionian Sea. At Site 964 the FCO of R. asanoi occurs in the marine oxygen isotope stage (MIS) 30, and the LCO of the species correlates with MIS 23. The ages of the FCO and LCO of R. asanoi have been estimated at 1.06 Ma and 0.93 Ma respectively. The first occurrence (FO) of Gephyrocapsa sp. 3 has been correlated to MIS 25, both at Site 964 and at the Montalbano Jonico section. The age of the FO of Gephyrocapsa sp. 3 is estimated at 0.95 Ma, based on the astronomical datings of sapropels occurring at the Montalbano Jonico section. In addition, an interval of temporary disappearance of Gephyrocapsa sp. 3 has been identified within the P. lacunosa Zone. The beginning of this interval is correlated with MIS 20/19 and can be considered a reliable event in the Mediterranean area, occurring close to the Brunhes/Matuyama magnetic boundary. The recognized events provide a basis for interpreting the Montalbano Jonico section within a standard chronostratigraphic framework

Chemical analyses of the clay fraction in selected samples of Sediment core KS09 (Table 2)

A deep-sea core over 16 m long from the crestal area of the Mediterranean Ridge has been investigated with different techniques, including quantitative micropaleontology, stable isotopes (measured on the epipelagic species Globigerinoides ruber and on the mesopelagic species Globorotalia inflata), and clay mineralogy. The resulting record of climatic fluctuations can be cross correlated to other Mediterranean cores by means of isochronous lithologies (tephra layers and sapropels). The climatic record of the Mediterranean is similar in character, phase, and chronology to the records investigated in the equatorial Pacific and in the Caribbean. Isotope stages 1 to 17 have been recognized. Cyclically repeated stagnant cycles resulting in sapropel deposition complicate both the isotopic and the faunal signal. The isotopic investigations reveal that the temperature change in the surface layers of the eastern Mediterranean was no greater than 8°C in the late “glacial” Pleistocene. The chronostratigraphic and biostratigraphic interpretation of Core KS09 indicate that the mean sedimentation rate was 2.4 cm/1000 years, a value very close to the 2.5 cm/1000 years calculated for the entire Quaternary section at DSDP Site 125, also located in the crestal area of the Mediterranean Ridge in the Ionian Basin. The base of KS09 is likely to be very close to the Brunhes/Matuyama boundary dated at 0.7 my

La sezione-tipo dello Ioniano, nuova unità cronostratigrafica del Pleistocene.

Présentation oral

Paleoproductivity modes in central Mediterranean during MIS 20 ‐ MIS 18: Calcareous plankton and alkenone variability

International audiencePaleoproductivity is reconstructed across a Mediterranean benchmark record, the Early/Middle Pleistocene Montalbano Jonico section, cropping out in southern Italy. High-resolution coccolithophore and alkenone data (C37 and C37:2/C38:2 ratio) were collected in order to extend the data set on Mediterranean paleoproductivity pattern and forcing mechanisms. The multi-proxy record indicates low productivity during glacial and stadial phases and enhanced productivity during interglacial and interstadials. Increased surface water turbidity, cold-water temperature and polar-subpolar low salinity water incursion appear as the dominant controls for low productivity during Marine Isotope Stage (MIS) 20. Enhanced productivity during MIS 19c was sustained by warmer surface waters, coupled with a seasonal precipitation regime, providing higher nutrient availability. Productivity increases during interstadials with respect to stadials, in relation with enhanced land-derived nutrient input through river discharge during wetter winters. The productivity scenario we propose is similar to those reconstructed from deep-sea records in the central and western Mediterranean during Dansgaard-Oeschger oscillations over the last 70 ka. This indicates that similar forcing mechanisms acted on productivity dynamics on a regional scale over different times. We suggest that migration of the westerly wind system over the Mediterranean and the polar water inflow influenced productivity on a regional scale. The acquired data set provides new evidences on the environmental significance of the C37:2/C38:2 ratio and on its relation with surface water productivity