Low-cost GNSS receivers have recently been gaining reliability as good candidates for ionospheric studies. In line with these gains are genuine concerns about improving the performance of these receivers. In this work...Low-cost GNSS receivers have recently been gaining reliability as good candidates for ionospheric studies. In line with these gains are genuine concerns about improving the performance of these receivers. In this work, we present a comprehensive investigation of the performances of two antennas(the u-blox ANN-MB and the TOPGNSS TOP-106) used on a low-cost GNSS receiver known as the u-blox ZED-F9P. The two antennas were installed on two identical and co-located u-blox receivers. Data used from both receivers cover the period from January to June 2022. Results from the study indicate that the signal strengths are dominantly greater for the receiver with the TOPGNSS antenna than for the receiver with the ANN-MB antenna, implying that the TOPGNSS antenna is better than the ANN-MB antenna in terms of providing greater signal strengths. Summarily, the TOPGNSS antenna also performed better in minimizing the occurrence of cycle slips on phase TEC measurements. There are no conspicuous differences between the variances(computed as 5-min standard deviations) of phase TEC measurements for the two antennas, except for a period around May-June when the TOPGNSS gave a better performance in terms of minimizing the variances in phase TEC. Remarkably, the ANN-MB antenna gave a better performance than the TOPGNSS antenna in terms of minimizing the variances in pseudorange TEC for some satellite observations. For precise horizontal(North and East) positioning, the receiver with the TOPGNSS antenna gave better results, while the receiver with the ANN-MB antenna gave better vertical(Up) positioning. The errors for the receivers of both antennas are typically within about 5 m(the monthly mean was usually smaller than 1 m) in the horizontal direction and within about 10 m(the monthly mean was usually smaller than 4 m) in the vertical direction.展开更多
Earthquake is a sudden release of energy due to fault motions.The severity of the damages can be minimized by development of a culture of prevention which includes the Seismic Hazard Assessment,microzonation studies a...Earthquake is a sudden release of energy due to fault motions.The severity of the damages can be minimized by development of a culture of prevention which includes the Seismic Hazard Assessment,microzonation studies and appropriate building codes.展开更多
In this work,an approach is developed to study the seismicity associated with the impoundment and level changes of a water reservoir(reservoir induced seismicity e RIS).The proposed methodology features a combination ...In this work,an approach is developed to study the seismicity associated with the impoundment and level changes of a water reservoir(reservoir induced seismicity e RIS).The proposed methodology features a combination of a semi-analytical poroelastic model with an earthquake nucleation approach based on rate-and-state frictional law.The combined approach was applied to the case of the Pertusillo Lake,located in the Val d’Agri area(Italy),whose large seasonal water level changes are believed to induce protracted micro-seismicity(local magnitude ML<3).Results show that the lake impoundment in 1962 could have produced up to 0.5 bar(1 bar=100 kPa)changes in Coulomb failure stress(DCFS),while the seasonal water level variation is responsible for variation up to 0.05 bar.Modeling results of the seismicity rates in 20012014 show that the observed earthquakes are well correlated with the modeled DCFS.Finally,the reason that the seismicity is only observed at southwest of the Pertusillo Lake is provided,which is likely attributed to different rock lithologies and depletion caused by significant hydrocarbon exploitation in the northeastern sector of the lake.展开更多
Earth Science observations and the Borexino and KamLAND geoneutrino experiments provide clues on the role of aether in the evolution of the Earth, planets, and all other universal structures. Analysis of the problem o...Earth Science observations and the Borexino and KamLAND geoneutrino experiments provide clues on the role of aether in the evolution of the Earth, planets, and all other universal structures. Analysis of the problem of storage of aether entering celestial bodies led to a hydrodynamic explanation of gravitation which in turn was found to be closely related to the expanding Earth and to several other phenomena. Variable radius paleogeography provides an approximate assessment of the quantity of ordinary matter added to the planet per time unit, and some inferences about the Earth’s inner energy balance. The aether density, flow rate, and velocity are computed with the help of astrophysics. The origins of cosmological and gravitational redshift are unified under the single cause of gravitation. This is linked to the similar but not interchangeable concept of tired light, which was considered very plausible by cosmologists like Edwin Hubble and Fritz Zwicky. A superluminal speed was calculated for aether at the Earth’s surface. INFN experiments confirm hydrodynamic gravitation and superluminal velocities, and it is possible to identify interrelations of aether parameters with the currently known cosmological parameters H<sub>0</sub>, G, and c. Unification of hydrodynamic gravitation and the expansion of the celestial bodies through the existence of a minor dissipative force, a non-Newtonian concept, involves a revision of the theories of physics and cosmology, in which the currently accepted laws of physics will be only considered good approximations of a more complex reality.展开更多
Seismic data of earthquakes recorded during the last 40 years in southern Calabria have been compared with geological data in order to obtain a seismotectonic picture of the area. We sought for any possible correlatio...Seismic data of earthquakes recorded during the last 40 years in southern Calabria have been compared with geological data in order to obtain a seismotectonic picture of the area. We sought for any possible correlation between the main regional tectonic structures, the distribution of earthquake hypocentres and the focal mechanism of earthquakes with magnitude(Ml)≥3.Studies of historical and recent seismicity and analysis of geological structures allowed to define the main shear strips on a regional scale. More than 2600 earthquakes with 1.5 ≤ Ml ≤ 4.5 have been considered. The focal mechanisms of earthquakes with Ml≥3 have been compared with the kinematics of known faults and used to give insight on the current active stress field. From the analysis carried out it was possible to expand the cognitive framework regarding the activity of the main tectonic structures present in the area. This study also served to identify areas of high seismicity which do not correspond to any evidence of tectonic structures on the surface, and areas where recognized tectonic structures have not shown any seismicity during the last decades. These cases could be the subject of future investigation in order to correctly assess the seismic hazard in Calabria.This task is important in the context of seismic hazard evaluation and mitigation.展开更多
The tectonics and geodynamics of the Calabria region are presented in this study. These are inferred by precise computation of Global Navigation Satellite Systems (GNSS) per~ manent station velocities in a stable Eu...The tectonics and geodynamics of the Calabria region are presented in this study. These are inferred by precise computation of Global Navigation Satellite Systems (GNSS) per~ manent station velocities in a stable Eurasian reference framework. This allowed computation of the coordinates, variance and covariance matrixes, and horizontal and vertical velocities of the 36 permanent sites analyzed, together with the strain rates, and using different techniques. Interesting geodynamic phenomena are presented, including compressional, and deformational fields in the Tyrrhenian coastal sites of Calabria, extensional trends of the Ionian coastal sites, and sliding movement of the Crotone Basin. Conversely, on the northern Tyrrhenian side of the network near the Cilento Park area, the usual extensional tectonic perpendicular to the Apennine chain is observed. The large- scale pattern of the GNSS height velocities is shown, which is characterized by general interesting geodynamic vertical effects that appear to be due to geophysical movement and anthropic activity. Finally, the strain-rate fields computed through three different tech- niques are compared.展开更多
In May 2012 a seismic sequence occurred in Northern Italy that was characterized by two main shocks with a magnitude range between 5.5 and 6. These shocks represent a good case study by which to quantify the monetary ...In May 2012 a seismic sequence occurred in Northern Italy that was characterized by two main shocks with a magnitude range between 5.5 and 6. These shocks represent a good case study by which to quantify the monetary losses caused by a moderate earthquake in a densely populated and economically well-developed area.The loss estimation accounts for damage to residential buildings, and considers the full effect of all the seismic aftershock events that lasted for nearly a month. The building damage estimation is based on the European Macroseismic Scale(EMS-98) definitions, which depict the effects of an earthquake on built-up areas in terms of observed intensities. Input data sources are the residential building census provided by Istituto Nazionale di Statistica—the Italian National Institute of Statistics(ISTAT)—and the official market value of real estate assets, obtained from the Osservatorio del Mercato Immobiliare—the Real Estate Market Observatory(OMI). These data make it possible to quantify the economic losses due to earthquakes, an economic indicator updated yearly. The proposed multidisciplinary method takes advantage of seismic,engineering, and economic data sets, and is able to provide a reasonable after the event losses scenario. Data are not gathered for each single building and the intensity values are not a simple hazard indicator, but, notwithstanding its coarseness, this method ensures both robust and reproducible results. As the local property value is availablethroughout the Italian territory, the present loss assessment can be effortlessly repeated for any area, and may be quickly reproduced in case of future events, or used for predictive economic estimations.展开更多
During ancient times,human interest in naturally-occurring gases was religious,while it was scientific in the historical age and industrial in modern times.Gases were also utilized for practical purposes and more than...During ancient times,human interest in naturally-occurring gases was religious,while it was scientific in the historical age and industrial in modern times.Gases were also utilized for practical purposes and more than 3000 years before present day,Chinese populations made use of methane for salt extraction while in the 17th century it was observed that native Americans ignited methane seepages.The development of human thinking on gases followed the fundamental steps that characterized the natural sciences during the 18th century scientific revolution that was based on significant improvements in analytical methods.These improvements are still ongoing while present-day scientific publications evidence the spread of the field of interest and more cooperation with geophysical sciences to solve common interest problems.The existence of proper meetings and dedicated scientific journals confirms that gas geochemistry has ended this pioneering phase to enter a more mature condition.展开更多
基金Centre for Atmospheric Research,Nigeria,for providing the research grant required to conduct this study。
文摘Low-cost GNSS receivers have recently been gaining reliability as good candidates for ionospheric studies. In line with these gains are genuine concerns about improving the performance of these receivers. In this work, we present a comprehensive investigation of the performances of two antennas(the u-blox ANN-MB and the TOPGNSS TOP-106) used on a low-cost GNSS receiver known as the u-blox ZED-F9P. The two antennas were installed on two identical and co-located u-blox receivers. Data used from both receivers cover the period from January to June 2022. Results from the study indicate that the signal strengths are dominantly greater for the receiver with the TOPGNSS antenna than for the receiver with the ANN-MB antenna, implying that the TOPGNSS antenna is better than the ANN-MB antenna in terms of providing greater signal strengths. Summarily, the TOPGNSS antenna also performed better in minimizing the occurrence of cycle slips on phase TEC measurements. There are no conspicuous differences between the variances(computed as 5-min standard deviations) of phase TEC measurements for the two antennas, except for a period around May-June when the TOPGNSS gave a better performance in terms of minimizing the variances in phase TEC. Remarkably, the ANN-MB antenna gave a better performance than the TOPGNSS antenna in terms of minimizing the variances in pseudorange TEC for some satellite observations. For precise horizontal(North and East) positioning, the receiver with the TOPGNSS antenna gave better results, while the receiver with the ANN-MB antenna gave better vertical(Up) positioning. The errors for the receivers of both antennas are typically within about 5 m(the monthly mean was usually smaller than 1 m) in the horizontal direction and within about 10 m(the monthly mean was usually smaller than 4 m) in the vertical direction.
基金partially supported by the Chinese Academy of Sciences Visiting Professorship for Senior International Scientists(2018VMA0007)
文摘Earthquake is a sudden release of energy due to fault motions.The severity of the damages can be minimized by development of a culture of prevention which includes the Seismic Hazard Assessment,microzonation studies and appropriate building codes.
基金funded by a research agreement between the Swiss Seismological Service(SED)and the Istituto Nazionale di Geofisica e Vulcanologiathe RISE project under the European Union’s Horizon 2020 research and innovation programme(Grant No.821115)financed by a SNSF Ambizione Energy grant(PZENP2160555)。
文摘In this work,an approach is developed to study the seismicity associated with the impoundment and level changes of a water reservoir(reservoir induced seismicity e RIS).The proposed methodology features a combination of a semi-analytical poroelastic model with an earthquake nucleation approach based on rate-and-state frictional law.The combined approach was applied to the case of the Pertusillo Lake,located in the Val d’Agri area(Italy),whose large seasonal water level changes are believed to induce protracted micro-seismicity(local magnitude ML<3).Results show that the lake impoundment in 1962 could have produced up to 0.5 bar(1 bar=100 kPa)changes in Coulomb failure stress(DCFS),while the seasonal water level variation is responsible for variation up to 0.05 bar.Modeling results of the seismicity rates in 20012014 show that the observed earthquakes are well correlated with the modeled DCFS.Finally,the reason that the seismicity is only observed at southwest of the Pertusillo Lake is provided,which is likely attributed to different rock lithologies and depletion caused by significant hydrocarbon exploitation in the northeastern sector of the lake.
文摘Earth Science observations and the Borexino and KamLAND geoneutrino experiments provide clues on the role of aether in the evolution of the Earth, planets, and all other universal structures. Analysis of the problem of storage of aether entering celestial bodies led to a hydrodynamic explanation of gravitation which in turn was found to be closely related to the expanding Earth and to several other phenomena. Variable radius paleogeography provides an approximate assessment of the quantity of ordinary matter added to the planet per time unit, and some inferences about the Earth’s inner energy balance. The aether density, flow rate, and velocity are computed with the help of astrophysics. The origins of cosmological and gravitational redshift are unified under the single cause of gravitation. This is linked to the similar but not interchangeable concept of tired light, which was considered very plausible by cosmologists like Edwin Hubble and Fritz Zwicky. A superluminal speed was calculated for aether at the Earth’s surface. INFN experiments confirm hydrodynamic gravitation and superluminal velocities, and it is possible to identify interrelations of aether parameters with the currently known cosmological parameters H<sub>0</sub>, G, and c. Unification of hydrodynamic gravitation and the expansion of the celestial bodies through the existence of a minor dissipative force, a non-Newtonian concept, involves a revision of the theories of physics and cosmology, in which the currently accepted laws of physics will be only considered good approximations of a more complex reality.
文摘Seismic data of earthquakes recorded during the last 40 years in southern Calabria have been compared with geological data in order to obtain a seismotectonic picture of the area. We sought for any possible correlation between the main regional tectonic structures, the distribution of earthquake hypocentres and the focal mechanism of earthquakes with magnitude(Ml)≥3.Studies of historical and recent seismicity and analysis of geological structures allowed to define the main shear strips on a regional scale. More than 2600 earthquakes with 1.5 ≤ Ml ≤ 4.5 have been considered. The focal mechanisms of earthquakes with Ml≥3 have been compared with the kinematics of known faults and used to give insight on the current active stress field. From the analysis carried out it was possible to expand the cognitive framework regarding the activity of the main tectonic structures present in the area. This study also served to identify areas of high seismicity which do not correspond to any evidence of tectonic structures on the surface, and areas where recognized tectonic structures have not shown any seismicity during the last decades. These cases could be the subject of future investigation in order to correctly assess the seismic hazard in Calabria.This task is important in the context of seismic hazard evaluation and mitigation.
文摘The tectonics and geodynamics of the Calabria region are presented in this study. These are inferred by precise computation of Global Navigation Satellite Systems (GNSS) per~ manent station velocities in a stable Eurasian reference framework. This allowed computation of the coordinates, variance and covariance matrixes, and horizontal and vertical velocities of the 36 permanent sites analyzed, together with the strain rates, and using different techniques. Interesting geodynamic phenomena are presented, including compressional, and deformational fields in the Tyrrhenian coastal sites of Calabria, extensional trends of the Ionian coastal sites, and sliding movement of the Crotone Basin. Conversely, on the northern Tyrrhenian side of the network near the Cilento Park area, the usual extensional tectonic perpendicular to the Apennine chain is observed. The large- scale pattern of the GNSS height velocities is shown, which is characterized by general interesting geodynamic vertical effects that appear to be due to geophysical movement and anthropic activity. Finally, the strain-rate fields computed through three different tech- niques are compared.
基金the project ‘‘The Economic Assessment of Natural Disasters in Italy’’ (La valutazione economica dei disastri naturali in Italia, in Italian) funded by Fondazione Generali from 2013 to 2017
文摘In May 2012 a seismic sequence occurred in Northern Italy that was characterized by two main shocks with a magnitude range between 5.5 and 6. These shocks represent a good case study by which to quantify the monetary losses caused by a moderate earthquake in a densely populated and economically well-developed area.The loss estimation accounts for damage to residential buildings, and considers the full effect of all the seismic aftershock events that lasted for nearly a month. The building damage estimation is based on the European Macroseismic Scale(EMS-98) definitions, which depict the effects of an earthquake on built-up areas in terms of observed intensities. Input data sources are the residential building census provided by Istituto Nazionale di Statistica—the Italian National Institute of Statistics(ISTAT)—and the official market value of real estate assets, obtained from the Osservatorio del Mercato Immobiliare—the Real Estate Market Observatory(OMI). These data make it possible to quantify the economic losses due to earthquakes, an economic indicator updated yearly. The proposed multidisciplinary method takes advantage of seismic,engineering, and economic data sets, and is able to provide a reasonable after the event losses scenario. Data are not gathered for each single building and the intensity values are not a simple hazard indicator, but, notwithstanding its coarseness, this method ensures both robust and reproducible results. As the local property value is availablethroughout the Italian territory, the present loss assessment can be effortlessly repeated for any area, and may be quickly reproduced in case of future events, or used for predictive economic estimations.
基金supported partially by the National Science and Technology Major Project of the Ministry of Science and Technology of China(Nos.2021YFA0719003,2019YFA0708501)funds from Chinese Academy of Sciences as a visiting professorship for senior international scientists(No.2018VMA0007)。
文摘During ancient times,human interest in naturally-occurring gases was religious,while it was scientific in the historical age and industrial in modern times.Gases were also utilized for practical purposes and more than 3000 years before present day,Chinese populations made use of methane for salt extraction while in the 17th century it was observed that native Americans ignited methane seepages.The development of human thinking on gases followed the fundamental steps that characterized the natural sciences during the 18th century scientific revolution that was based on significant improvements in analytical methods.These improvements are still ongoing while present-day scientific publications evidence the spread of the field of interest and more cooperation with geophysical sciences to solve common interest problems.The existence of proper meetings and dedicated scientific journals confirms that gas geochemistry has ended this pioneering phase to enter a more mature condition.