The climatology of tornadoes and waterspouts in Italy

In this work 10 years of reports collected by weather amateurs are used to define a preliminary climatology of tornadoes and waterspouts in Italy. The results show behaviors different from those observed in other countries. Generally, tornadoes and waterspouts are more frequent in late summer and autumn than in the other seasons. The seasonality of tornadoes and waterspouts appears different for different Italian zones, in particular in the Po Valley and Friulian plain and coast (south to the Alps) tornadoes and waterspouts are more frequent in spring and early summer while in the Tirrenian and Ionian coasts (western and southern Italy), tornadoes and waterspouts are more frequent in late summer and autumn. As observed in other studies (Brooks, H., E. and Doswell, C. A. III, 2001. Some aspects of the international climatology of tornadoes by damage classification. Atmos. Res., 56, 191–201.) Italian tornadoes and waterspouts are statistically weaker than in other countries but this difference cannot be completely ascribed to the presence of waterspouts. The “CAPE Storm-Relative-Helicity diagrams” and “Shear Magnitude diagrams” obtained for Italian tornadoes and waterspouts show different characteristics than those obtained for US. The cause of these differences is still unknown, it can rely in the sample selection (problems with the concept of proximity sounding) or in a real climatic effect.     

U-Pb SHRIMP zircon dating of andesite from the Dolomite area (NE Italy): geochronological evidence for the early onset of Permian Volcanism in the eastern part of the southern Alps

The Athesian Volcanic District (AVD), a thick sequence of andesitic to rhyolitic lava and ignimbrite, overlies both the Variscan basement of the Dolomites and, where present, the continental basal conglomerate of Upper Carboniferous(?) to Early Permian age. This volcanic activity is known to mark the margin of the intra-Pangea megashear system between Gondwana and Laurasia, the onset age of which is determined in this study.SHRIMP U-Pb dating on zircon from Ponte Gardena/Waidbruck (Isarco/Eisack valley) basaltic andesite yields an age of 290.7 ± 3 Ma, providing the oldest record of andesite volcanic activity yet documented in the AVD. Two younger dates (279.9 ± 3.3 and 278.6 ± 3.1 Ma) obtained for the andesitic necks of M. dei Ginepri (Eores/Aferer valley) and Col Quaternà (western Comelico), respectively, probably represent a second pulse of andesite magmatic activity.Near Chiusa/Klausen, the volcanoclastic deposits at the bottom of the Funes/Villnöss valley volcano-sedimentary complex only contain detrital zircons, dated at 469 ± 6 Ma; these probably derive from erosion of Paleozoic porphyroids. Other zircons from the same sediments and inherited cores of magmatic andesite crystals give Paleoproterozoic (1953.6 ± 22.1, 1834.6 ± 69.3, 1773.6 ± 25.1 Ma), Early Neoproterozoic (1015 ± 14 Ma) and Late Neoproterozoic (728.4 ± 9.6, 687.6 ± 7.6 Ma) ages. These ancient detrital and inherited zircon ages fit the model that envisages the Dolomite region as being tectonically coherent with Africa, at least until the Lower Permian.     

The antiquity indicator argon‐40/argon‐36 for lunar surface samples calibrated by uranium‐235‐xenon‐136 dating

Abstract— Several solar gas rich lunar soils and breccias have trapped ⁴⁰Ar/³⁶Ar ratios >10, although solar Ar is expected to yield a ratio of <0.01. Radiogenic ⁴⁰Ar produced in the lunar crust from ⁴⁰K decay was outgassed into the lunar atmosphere, ionized, accelerated in the electromagnetic field of the solar wind, and reimplanted into lunar surface material. The ⁴⁰Ar loss rate depends on the decreasing abundance of ⁴⁰K. In order to calibrate the time dependence of the ⁴⁰Ar/³⁶Ar ratio in lunar surface material, the period of reimplantation of lunar atmospheric ions and of solar wind Ar was determined using the ²³⁵U‐¹³⁶Xe dating method that relies on secondary cosmic‐ray neutron‐induced fission of ²³⁵U. We identified the trapped, fissiogenic, and cosmogenic noble gases in lunar breccia 14307 and lunar soils 70001‐8, 70181, 74261, and 75081. Uranium and Th concentrations were determined in the 74261 soil for which we obtain the ²³⁵U‐¹³⁶Xe time of implantation of 3.25^+0.38_‐0.60 Ga ago. On the basis of several cosmogenic noble gas signatures we calculate the duration of this near surface exposure of 393 ± 45 Ma and an average shielding depth below the lunar surface of 73 ± 7 g/cm². A second, recent exposure to solar and cosmic‐ray particles occurred after this soil was excavated from Shorty crater 17.2 ± 1.4 Ma ago. Using a compilation of all lunar data with reliable trapped Ar isotopic ratios and pre‐exposure times we infer a calibration curve of implantation times, based on the trapped⁴⁰ Ar/³⁶Ar ratio. A possible trend for the increase with time of the solar ³He/⁴He and ²⁰Ne/²²Ne ratios of about 12%/Ga and about 2%/Ga, respectively, is also discussed.     

Flood Events of Selected European Rivers in the Sixteenth Century

The severity and frequency of sixteenth-century floods of the Rhine, the Main, the middle and upper Elbe with its tributaries, rivers of northern and central Italy, the Garonne and rivers in Catalonia and Andalusia are analyzed using documentary evidence. The basic topographical and hydrological characteristics of the rivers investigated as well as the synoptic causes of their flooding during the instrumental period are presented. Different examples of modifications of the run-off process due to anthropogenic activity are discussed. Prevalence in flood occurrence during the second half of the sixteenth century in comparison to the first half is typical for central European and Andalusian rivers (mainly in the 1560s and 1590s) and agrees with the evolution of precipitation patterns. On the other hand, Italian and Catalonian rivers, in part, had a higher occurrence of floods during the first half of the century. Changes in the flooding seasons in both halves of the century are not unambiguous. Results of an analysis on a broader European scale show floods to be a random natural phenomena with limited areal extent defined by the spatial influence of forcing meteorological factors (continuous heavy rains, sudden melting of thick snow cover, etc.). Despite some limitations of documentary evidence, series of reconstructed historical floods are valuable sources of proxy data which can be utilized for the study of the flooding fluctuations in the pre-instrumental period.     

Reconnaissance geology in Upper Chitral,Baroghil and Karambar districts (northern Karakorum,Pakistan)

During the summer of 1992 a geological expedition crossed the northern Karakorum range in northern Pakistan, from the Chitral to Karambar valleys, from the villages of Mastuj to Imit. Some of the areas visited were geologically unknown. A number of structural units were crossed, belonging to the Karakorum block or to other crustal blocks north of it. They are: (a) the axial batholith, in which three plutonic bodies have been identified, and (b) the northern sedimentary belt (NSB), in which three major tectonostratigraphic units form thrust stacks dipping to the north. Their internal stratigraphy and structural style are partly different. The most complete contains a crystalline basement, transgressed by a marine succession during the Early Ordovician. The youngest strata are represented by the Reshun conglomerate, of inferred Cretaceous age. The northernmost unit of the NSB is tightly folded, whereas the central one forms a monocline. Vertical faults, mainly strike-slip, dissect the thrusted slabs. Metamorphic deformation is absent or reaches only the anchizone in the studied sector of the Karakorum NSB. To the north of the Karakorum proper there are several other tectonic units, separated by vertical faults. They are, from south to north: (a) the Taš Kupruk zone, with metavolcanics of basaltic to latibasaltic composition; (b) the Atark unit, mostly consisting of massive carbonate rocks of Mesozoic age; and (c) the Wakhan slates which consist of a thick widespread succession of dark slates, metasiltites and sandstones. The fine-grained elastic rocks are supposed to be Palaeozoic to Early Triassic in age. The Wakhan slates are intruded by plutons belonging to the East Hindu Kush batholith, from which a single K/Ar age on muscovite gave a Jurassic age.     

Impact of the clouds of volcanic aerosols in Italy during the last 7 centuries

Intense natural pollution has occurred in the past in Italy corresponding to intense volcanic activity, which appears to have diminished somewhat in recent times. Between 1500 and 1900, Etna, Vesuvius, Vulcano and Stromboli, plus volcanoes outside Italy were very active and there are numerous, well documented episodes of atmospheric acidification which caused widespread damage, especially to the vegetation. Other than the acid rains, volcanic emissions also caused so calleddry fogs which consist of a more or less dense mist composed of foul smelling gases and aerosols, characterized by a reddish color, that could appear and persist when the relative humidity was low as shown by measurements taken on such occasions. This phenomenon appeared most frequently at the beginning of the hot season. In fact, volcanic clouds of gases and aerosols formed especially when the Tyrrhenian sea water was relatively cold giving rise to very stable atmospheric conditions locally and the summer anticyclone meant that the winds were calm. Under such conditions the emissions of Stromboli and Vulcano, especially those emitted at low levels, remained entrapped in the stable layer, which were then transported towards the land reaching Northern Italy at a distance on the order of 10³ km. Thedry fogs could persist for days or weeks. Harvests were seriously damaged and frequently the crops were subsequently attacked by parasites. The leaves of the vegetation became discoloured with numerous punctiform lesions or gangrene at the edges of the leaves. The phenomenon was so frequent that, in texts on agricultural meteorology of the 1800s, a distinction was made between the causticdry fogs which damaged the vegetation anddamp fogs which instead were good for it. The most important episode occurred in 1783 due to the activity of Laki Grímsvötn (Iceland) with the contribution of Italian volcanoes. This dry fog lasted many months and affected the greater part of the northern hemisphere including Europe and Asia, harming people, animals and vegetation. Apart from paroxysmal cases, from the 1300s up to today, some tens ofdry fogs have been noted, all of which have been sufficiently well documented. The frequency of these events culminated between the middle of the 1700s and the middle of the 1800s. There is reason to believe that this well documented phenomenon of the past, with sufficient volcanic activity, could recur on the meso and large scale; with present day activity the emissions continue to cause damage to vegetation, both in the Aspromonte mountains (Calabria, Southem Italy) as well as in other parts of Italy.     

Temperature observations in Bologna,Italy, from 1715 to 1815: a comparison with other contemporary series and an overview of three centuries of changing climate

The observations taken in Bologna, Italy, from 1715 to 1815, three times a day, with a number of thermometers (i.e., Stancari air thermometers, Little Florentine thermometer, Florentine stick thermometer and a number of Réaumur spirit and mercury thermometers) some of them operating in parallel, have been recovered and analysed. The early thermometers had unknown scales and temperature units, with deviations due to the bulb shape or the thermometric liquid, but it is possible to interpret them after comparison between parallel readings. Historical sources and the analysis of the data fingerprints and their variability permit recognition of where instruments were located and who the observers were. It is also possible to relate the indoor climate of historical buildings to the outdoor one, and transform indoor readings as they were taken outdoors, expressed in Celsius. The Bologna series has been compared with the contemporary observations in Padua, Venice and Milano. The climate analysis shows that the temperature fluctuated but with an increasing trend. The 1730–1770 decades constituted the coldest period and 1980—today the warmest one. The eighteenth century was generally cold and had an impressive frequency of extremely severe winters that exceeded the rest of the series. The whole dataset (i.e. 1715–2015) of daily temperatures has been included to allow further use for scientific purposes. Finally, the paper provides a methodological example of procedures to recover and analyse early instrumental series.     

Protection of a monumental building against traffic-induced vibrations

To preserve an ancient building in Rome against traffic-induced vibrations, an anti-vibration system was introduced under the paving of the near Lungotevere road. An experimental investigation was recently carried out by ENEA in order to analyse the traffic-induced vibrations in the basement of the building and the effectiveness of the intervention. Wave propagation in the soil around the building in presence of the anti-vibration paving was compared with that in absence of the anti-vibration paving. The study showed the importance of the taking into account the contribution of other structures in the area to the dynamic behaviour of the whole system.     

Inferences on the main volcano-tectonic structures at Mt. Etna (Sicily) from a probabilistic seismological approach

We analysed earthquakes at Mt. Etna for the period 1983–1991 using a method that weights uncertainties in hypocentral location. Three-dimensional distributions of hypocentral probability and energy density were studied, and two first-order volcano-tectonic structures identified. The first, on the northern and western sides, is roughly NE–SW oriented, and strongly marks the northernmost limit of earthquake occurrences in the volcano region; the second, NNW–SSE trending, affects the south-eastern flank of the volcano, and is evidence for an almost aseismic uprise of magma along it. Both structures fit well with the geodynamic framework of eastern Sicily. On the contrary, there is no evidence for a main magma chamber, as postulated in the literature.