Landsscape diachronic reconstruction in the Tiber Delta during historical time. A holistic approach

The sensitivity of deltas in response to evolutionary factors makes them important archives of the events that occurred in the entire river basin. Detailed knowledge of the stratigraphy and morphology, combined with a set of archaeological, palaeobotanical and historical information, make possible to reconstruct the diachronic changes of the landscape in the Tiber delta plain over the past 3000 years taking into account natural and anthropic forcing. The main factors that contributed to the delta landscape change are considered following a temporal scansion. Among the natural factors, we considered climate, sea level rise, tectonic and local subsidence. Among the human factors we considered the population density and several human activities, such as farming and breeding practices, reclamation, construction of ports, canals and salt works. To evaluate the amount of sediment involved in the delta evolution during different periods, the BQART model was used. Prior to Roman times anthropogenic forcing had a lower influence than natural forcing on the landscape evolution. During the Roman period (between third century BC-fourth century AD), the delta landscape was severely conditioned by the human activity. Throughout the Middle Ages and until the first half of the nineteenth century, a more natural landscape evolved in the delta, gradually and partially replacing the previous landscape. With the arrival of the new Italian State a new and impressive landscape change occurred. The evolution of the Tiber delta landscape appear particularly affected by anthropogenic forcing when socio-political organization allowed the control and planning of policy actions

Natural and anthropogenic forcing during the last two centuries in Ombrone Delta (Southern Tuscany - Central Italy)

This study describes advances in understanding of the recent evolution of the Ombrone River delta. Several aspects have been studied and updated: the stages of progradation and retreat of the shoreline from the Middle Ages, with particular reference to the last 200 years, have been reconstructed and the natural and/or human forcing responsible for the area’s evolution have been hypothesized. The processes that led to the formation and evolution of some small coastal lakes and the more recent evolution of the shoreline are defi ned. Monitoring of shoreline variations in the Ombrone Delta apex has been achieved by comparing aerial photos acquired in 1995, 1998, 2004, 2006 and 2010. The progressive landward migration of the shoreline has resulted in a realignment of the coast. Comparison with older erosion and progradation rates shows decreasing erosion rates along the delta apex with time: the erosion rate of the northern wing has reached peaks of around 14 m/yr (2004-2006), and then fallen to 4.5 m/yr in the latest period (2006-2010). The Ombrone River delta is characterized by the presence of beach ridges, ponds and, in the past, of a coastal lake. Morpho- bathymetric analysis and comparison with historical maps shows that during the XIX century, the historical lake preserved its geometry; only in the 1883 map seaward side presents an irregular geometry, while in the 1929 map the ponds have been represented for the fi rst time and are located seaward with respectto the XIX century beach ridge. Comparing morpho-bathymetric data of Chiaro Grande pond and submerged apical mouth, this study confi rmed the hypothesisabout Chiaro Grande pond genesis in which its formation is based on the closure of a narrow sea stretch consequent to the emergence of a bar. The independence between the genesis of ponds and lake evolution, highlighting the importance of mouth bar growth as a recurrent mechanism for confi ning narrow sea stretches. The orientation of morphological features and the prevailing wave climate suggest a sediment transport from south to north

Regime fluviale del Tevere e variazione del litorale deltizio dal Rinascimento ai nostri giorni

pp. 50-5

Atmospheric neutrino induced muons in the MACRO detector

A measurement of the flux of neutrino-induced muons using the MACRO detector is presented. Different event topologies, corresponding to different neutrino parent energies can be detected. The upward throughgoing muon sample is the larger event sample. The observed upward-throughgoing muons are 26% fewer than expected and the zenith angle distribution does not fit with the expected one. Assuming neutrino oscillations, both measurements suggest maximum mixing and Dm2 of a few times 10-3 eV2. The other samples are due to the internally produced events and to upward-going stopping muons. These data show a regular deficit of observed events in each angular bin, as expected assuming neutrino oscillations with maximum mixing, in agreement with the analysis of the upward-throughgoing muon sample.Comment: 7 pages 6 figures to appear in the proceedings of XVIII International Conference on Neutrino Physics and Astrophysics (Neutrino'98), Takayama, Japan 4-9 June, 199

Cosmic ray oriented performance studies for the JEM-EUSO first level trigger

JEM-EUSO is a space mission designed to investigate Ultra-High Energy Cosmic Rays and Neutrinos (E > 5 ⋅ 1019 eV) from the International Space Station (ISS). Looking down from above its wide angle telescope is able to observe their air showers and collect such data from a very wide area. Highly specific trigger algorithms are needed to drastically reduce the data load in the presence of both atmospheric and human activity related background light, yet retain the rare cosmic ray events recorded in the telescope. We report the performance in offline testing of the first level trigger algorithm on data from JEM-EUSO prototypes and laboratory measurements observing different light sources: data taken during a high altitude balloon flight over Canada, laser pulses observed from the ground traversing the real atmosphere, and model landscapes reproducing realistic aspect ratios and light conditions as would be seen from the ISS itself. The first level trigger logic successfully kept the trigger rate within the permissible bounds when challenged with artificially produced as well as naturally encountered night sky background fluctuations and while retaining events with general air-shower characteristics