Nitrogen dioxide concentrations, being short-lived pollutants, are good indicators of changes in emission sources and economic slowdowns. This analysis focuses on the Greater Salento region (Italy) and aims to monitor...Nitrogen dioxide concentrations, being short-lived pollutants, are good indicators of changes in emission sources and economic slowdowns. This analysis focuses on the Greater Salento region (Italy) and aims to monitor, by investigating the relative sources, the changes of NO<sub>2</sub> tropospheric concentrations notoriously related to vehicular traffic exhausts and, in general, to fossil fuel combustion processes which are now apparently linked to many COVID-19 patients deaths. The principle objective of this paper is to map the tropospheric NO<sub>2</sub> local distribution and to extrapolate, from the overall data of average daily concentrations of NO<sub>2</sub> as recorded by the ARPA-Puglia ground-based monitoring stations, the single contributions and their mutual relationships of the different diffuse emission sources (motor vehicles and domestic heating systems) by identifying, the environmental background threshold of this pollutant of each geographic area, thanks to the simplified situation determined by the COVID-19 lockdown. The analyzed territory (the so-called “Greater Salento” or Salento Peninsula) is very unusual because there are two provinces with large industrial settlements, Taranto, with the steel area of ex-ILVA, and Brindisi, with petrochemical and thermoelectric power plants, which enclose a territory, the province of Lecce, free of any industrial plants of such sizes and their environmental impacts. From the results of this study, in addition to confirming the obvious and overall decrease of NO<sub>2</sub> concentrations (-23.2% compared to previous year) during the lockdown period, interesting and distinctive local allocations of nitrogen dioxide concentrations to different sources have also emerged: heating household systems, and not road traffic, are the main sources of this dangerous pollutant in this region, with an average quota of 44.3%. The studied regional situation is so significant as to allow broader considerations regarding to other similar international areas.展开更多
In this paper we analysed the historical and instrumental seismicity of the seismic district “Penisola Salentina” (Salento peninsula) in the southern part of the Apuliaregion, making use of the most recent seismolog...In this paper we analysed the historical and instrumental seismicity of the seismic district “Penisola Salentina” (Salento peninsula) in the southern part of the Apuliaregion, making use of the most recent seismological database. Relocation of available dataset points out that the events are spatially distributed over a belt of deformation that approximately corresponds to Soglia Messapica (Taranto-Brindisi depression). Besides, computed source characteristics indicate dextral strike-slip solutions with an approximately E-W orientation that seismologically confirm previous geodynamic studies indicating a NE-SW extension in the Taranto-Brindisi depression. In particular, the tensional stress associated to the present seismic activity could be the consequence of the relaxation of the buckling process following the extensional re-arrangement of the Apenninic belt masses. Moreover attenuation QPvalues obtained in this study are much greater than those inferred in other parts of Italian peninsula;this result agrees with previous macroseismic investigations and indicates a greater efficiency of the studied area in the transmission of body waves.展开更多
文摘Nitrogen dioxide concentrations, being short-lived pollutants, are good indicators of changes in emission sources and economic slowdowns. This analysis focuses on the Greater Salento region (Italy) and aims to monitor, by investigating the relative sources, the changes of NO<sub>2</sub> tropospheric concentrations notoriously related to vehicular traffic exhausts and, in general, to fossil fuel combustion processes which are now apparently linked to many COVID-19 patients deaths. The principle objective of this paper is to map the tropospheric NO<sub>2</sub> local distribution and to extrapolate, from the overall data of average daily concentrations of NO<sub>2</sub> as recorded by the ARPA-Puglia ground-based monitoring stations, the single contributions and their mutual relationships of the different diffuse emission sources (motor vehicles and domestic heating systems) by identifying, the environmental background threshold of this pollutant of each geographic area, thanks to the simplified situation determined by the COVID-19 lockdown. The analyzed territory (the so-called “Greater Salento” or Salento Peninsula) is very unusual because there are two provinces with large industrial settlements, Taranto, with the steel area of ex-ILVA, and Brindisi, with petrochemical and thermoelectric power plants, which enclose a territory, the province of Lecce, free of any industrial plants of such sizes and their environmental impacts. From the results of this study, in addition to confirming the obvious and overall decrease of NO<sub>2</sub> concentrations (-23.2% compared to previous year) during the lockdown period, interesting and distinctive local allocations of nitrogen dioxide concentrations to different sources have also emerged: heating household systems, and not road traffic, are the main sources of this dangerous pollutant in this region, with an average quota of 44.3%. The studied regional situation is so significant as to allow broader considerations regarding to other similar international areas.
文摘In this paper we analysed the historical and instrumental seismicity of the seismic district “Penisola Salentina” (Salento peninsula) in the southern part of the Apuliaregion, making use of the most recent seismological database. Relocation of available dataset points out that the events are spatially distributed over a belt of deformation that approximately corresponds to Soglia Messapica (Taranto-Brindisi depression). Besides, computed source characteristics indicate dextral strike-slip solutions with an approximately E-W orientation that seismologically confirm previous geodynamic studies indicating a NE-SW extension in the Taranto-Brindisi depression. In particular, the tensional stress associated to the present seismic activity could be the consequence of the relaxation of the buckling process following the extensional re-arrangement of the Apenninic belt masses. Moreover attenuation QPvalues obtained in this study are much greater than those inferred in other parts of Italian peninsula;this result agrees with previous macroseismic investigations and indicates a greater efficiency of the studied area in the transmission of body waves.
