Absolute measurements of the acceleration of gravity were carried out in the areas of L'Aquila and Amatrice-Norcia, affected in the recent past by particularly intense seismic events
Through absolute measurements of the acceleration of gravity, a team of researchers from the National Institute of Geophysics and Volcanology (INGV) recorded and analyzed the variations of the earth's gravity field in the areas of Central Italy affected by the 2009 seismic events in L'Aquila and 2016 in Amatrice-Norcia.
The first results, recently published in the 'Remote Sensing' magazine in the article “Insights into Seismogenetic Areas in Central Italy from Combined Absolute Gravity and GNSS Measurement”, show that the whole area examined, in the period between 2018 and 2020, was affected by modest negative variations in the gravity field as a consequence of a decrease in density in the subsoil.
On the other hand, large and significant positive variations were recorded in the two stations in Umbria in Terni and in Abruzzo at the Gran Sasso Laboratory, in the time intervals from 1954 to 2020 and from 2005 to 2010.
The results were achieved through the analysis of a long series of data recorded with absolute gravimeters which also included the time frame in which the 2009 earthquakes in L'Aquila and 2016 in Amatrice-Norcia occurred.
These gravimetric variations observed in the long term are the consequence of mass/density changes in the subsoil in the pre- and post-seismic period.
Gravimetry is widely used in the field of earth sciences and, in particular, in the fields of geodesy, geophysics and geodynamics.
In the geodetic field, it finds application mainly for the development of reference models with respect to which it is intended to define the position of points on the earth's surface.
In geophysics it is mainly used for the definition of density models and discontinuity surfaces both at the surface level and in the deep crust and mantle.
Finally, in the geodynamic field, gravimetry makes it possible to follow the temporal evolution of numerous categories of phenomena capable of modifying the field of gravity, including tectonic processes, earthquakes and active volcanism.
Therefore, the gravimetric variations associated with earthquakes deserve particular attention as they can represent important precursors, contributing to the definition of dynamic models of energy accumulation and release.
Since the variations of the gravity field are sensitive to the vertical component of the deformation field, the gravimetric measurements must be associated with soil deformation measurements, in order to remove any deformation effect and to have only information on density variations from the correct gravimetric data and/or mass in the subsoil.
In Italy, despite a long tradition in the application of the gravimetric method in volcanic environments, capable of providing information on the state of activity of volcanoes over time, this method is not yet widely applied in seismogenic areas.
Therefore, the researchers hope that absolute gravimetric measurements and soil deformations will be repeated at sites in the Central Apennines, possibly by enlarging the survey network.
The results achieved with the data collected in recent years constitute, in fact, a reference base in the field of gravimetry and related sciences, also in the direction of a multidisciplinary approach for the improvement of knowledge of this seismogenic area of Italy, as well as a valid support for the creation of the new Italian reference gravimetric/altimetric network (G0/H0) which is under construction as part of the INGV Dynamic Planet project.
Link to the article
#ingv #gnss #earthquakes #gravimetry #eagle #norcia #amatrice
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INGV | Measured the absolute value of the earth's gravity in the seismogenic zones of the Central Apennines
Absolute measurements of the gravity acceleration have been carried out in the areas of L'Aquila and Amatrice-Norcia, affected in the recent past by seismic events of particular intensity
Through absolute gravimetric measurements, a team of researchers from the National Institute of Geophysics and Volcanology (INGV) recorded and analyzed the variations of the Earth's gravity field in the areas of Central Italy affected by the seismic events in L'Aquila (2009) and in Amatrice-Norcia (2016).
The first results, recently published in 'Remote Sensing' in the article “Insights into Seismogenetic Areas in Central Italy from Combined Absolute Gravity and GNSS Measurement”, show that the entire area examined, in the period between 2018 and 2020, was affected by modest negative variations in the gravity field as a consequence of a subsurface density decrease.
Large and significant positive changes, on the other hand, were recorded in the two stations in Umbria (in Terni) and in Abruzzo (at the Gran Sasso Laboratory), in the time frames from 1954 to 2020 and from 2005 to 2010.
The results were achieved through the analysis of a long series of data recorded with absolute gravimeters encompassing the time frame in which the earthquakes in L'Aquila (2009) and in Amatrice-Norcia (2016) occurred.
These gravimetric variations observed in the long term are the consequence of the subsurface mass/density changes in the pre- and post-seismic period.
Gravimetry is widely used in Earth Sciences and, in particular, in the fields of geodesy, geophysics and geodynamics.
In the geodetic field, it is mainly applied for the development of reference models with respect to which we intend to define the position of points on the Earth's surface.
In the geophysical field, it is used above all for the definition of density models and discontinuity surfaces both at the shallow level and in the deep Earth's crust and mantle.
Finally, in the geodynamic field, gravimetry allows scientists to follow the temporal evolution of numerous categories of phenomena capable of modifying the gravity field, including tectonic processes, earthquakes and active volcanism.
The gravimetric variations associated with earthquakes deserve particular attention as they can represent important precursors, contributing to the definition of dynamic models of energy storage and release.
Since the gravity variations are sensitive to the vertical component of the deformation field, gravimetric measurements must be associated with ground deformation measurements, in order to remove any deformation effect and obtain from the corrected gravity data only information on the subsurface density and/or mass variations .
In Italy, despite a long tradition in the application of the gravimetric method in volcanic areas, capable of providing information on the state of volcanoes activity over time, this method is not yet widely applied in seismogenic areas.
Therefore, the researchers hope for the repetition of absolute gravimetric and ground deformation measurements in the sites of the Central Apennines, possibly densifying the monitoring network.
In fact, the results achieved with the data collected in recent years constitute a benchmark for the scientific community working in the field of gravity applications and related sciences, also in the direction for a multidisciplinary approach towards improving the knowledge of this seismogenic area of Italy. The results should also be considered as a valid support for the realization of the new Italian gravimetric/altimetric reference network (G0/H0) which is in the construction stage as part of the INGV's “Pianeta Dinamico” project.
Link to the article
#ingv #gnss #earthquakes #eagle #norcia #amatrice
Through absolute measurements of the acceleration of gravity, a team of researchers from the National Institute of Geophysics and Volcanology (INGV) recorded and analyzed the variations of the earth's gravity field in the areas of Central Italy affected by the 2009 seismic events in L'Aquila and 2016 in Amatrice-Norcia.
The first results, recently published in the 'Remote Sensing' magazine in the article “Insights into Seismogenetic Areas in Central Italy from Combined Absolute Gravity and GNSS Measurement”, show that the whole area examined, in the period between 2018 and 2020, was affected by modest negative variations in the gravity field as a consequence of a decrease in density in the subsoil.
On the other hand, large and significant positive variations were recorded in the two stations in Umbria in Terni and in Abruzzo at the Gran Sasso Laboratory, in the time intervals from 1954 to 2020 and from 2005 to 2010.
The results were achieved through the analysis of a long series of data recorded with absolute gravimeters which also included the time frame in which the 2009 earthquakes in L'Aquila and 2016 in Amatrice-Norcia occurred.
These gravimetric variations observed in the long term are the consequence of mass/density changes in the subsoil in the pre- and post-seismic period.
Gravimetry is widely used in the field of earth sciences and, in particular, in the fields of geodesy, geophysics and geodynamics.
In the geodetic field, it finds application mainly for the development of reference models with respect to which it is intended to define the position of points on the earth's surface.
In geophysics it is mainly used for the definition of density models and discontinuity surfaces both at the surface level and in the deep crust and mantle.
Finally, in the geodynamic field, gravimetry makes it possible to follow the temporal evolution of numerous categories of phenomena capable of modifying the field of gravity, including tectonic processes, earthquakes and active volcanism.
Therefore, the gravimetric variations associated with earthquakes deserve particular attention as they can represent important precursors, contributing to the definition of dynamic models of energy accumulation and release.
Since the variations of the gravity field are sensitive to the vertical component of the deformation field, the gravimetric measurements must be associated with soil deformation measurements, in order to remove any deformation effect and to have only information on density variations from the correct gravimetric data and/or mass in the subsoil.
In Italy, despite a long tradition in the application of the gravimetric method in volcanic environments, capable of providing information on the state of activity of volcanoes over time, this method is not yet widely applied in seismogenic areas.
Therefore, the researchers hope that absolute gravimetric measurements and soil deformations will be repeated at sites in the Central Apennines, possibly by enlarging the survey network.
The results achieved with the data collected in recent years constitute, in fact, a reference base in the field of gravimetry and related sciences, also in the direction of a multidisciplinary approach for the improvement of knowledge of this seismogenic area of Italy, as well as a valid support for the creation of the new Italian reference gravimetric/altimetric network (G0/H0) which is under construction as part of the INGV Dynamic Planet project.
Link to the article
#ingv #gnss #earthquakes #gravimetry #eagle #norcia #amatrice
---
INGV | Measured the absolute value of the earth's gravity in the seismogenic zones of the Central Apennines
Absolute measurements of the gravity acceleration have been carried out in the areas of L'Aquila and Amatrice-Norcia, affected in the recent past by seismic events of particular intensity
Through absolute gravimetric measurements, a team of researchers from the National Institute of Geophysics and Volcanology (INGV) recorded and analyzed the variations of the Earth's gravity field in the areas of Central Italy affected by the seismic events in L'Aquila (2009) and in Amatrice-Norcia (2016).
The first results, recently published in 'Remote Sensing' in the article “Insights into Seismogenetic Areas in Central Italy from Combined Absolute Gravity and GNSS Measurement”, show that the entire area examined, in the period between 2018 and 2020, was affected by modest negative variations in the gravity field as a consequence of a subsurface density decrease.
Large and significant positive changes, on the other hand, were recorded in the two stations in Umbria (in Terni) and in Abruzzo (at the Gran Sasso Laboratory), in the time frames from 1954 to 2020 and from 2005 to 2010.
The results were achieved through the analysis of a long series of data recorded with absolute gravimeters encompassing the time frame in which the earthquakes in L'Aquila (2009) and in Amatrice-Norcia (2016) occurred.
These gravimetric variations observed in the long term are the consequence of the subsurface mass/density changes in the pre- and post-seismic period.
Gravimetry is widely used in Earth Sciences and, in particular, in the fields of geodesy, geophysics and geodynamics.
In the geodetic field, it is mainly applied for the development of reference models with respect to which we intend to define the position of points on the Earth's surface.
In the geophysical field, it is used above all for the definition of density models and discontinuity surfaces both at the shallow level and in the deep Earth's crust and mantle.
Finally, in the geodynamic field, gravimetry allows scientists to follow the temporal evolution of numerous categories of phenomena capable of modifying the gravity field, including tectonic processes, earthquakes and active volcanism.
The gravimetric variations associated with earthquakes deserve particular attention as they can represent important precursors, contributing to the definition of dynamic models of energy storage and release.
Since the gravity variations are sensitive to the vertical component of the deformation field, gravimetric measurements must be associated with ground deformation measurements, in order to remove any deformation effect and obtain from the corrected gravity data only information on the subsurface density and/or mass variations .
In Italy, despite a long tradition in the application of the gravimetric method in volcanic areas, capable of providing information on the state of volcanoes activity over time, this method is not yet widely applied in seismogenic areas.
Therefore, the researchers hope for the repetition of absolute gravimetric and ground deformation measurements in the sites of the Central Apennines, possibly densifying the monitoring network.
In fact, the results achieved with the data collected in recent years constitute a benchmark for the scientific community working in the field of gravity applications and related sciences, also in the direction for a multidisciplinary approach towards improving the knowledge of this seismogenic area of Italy. The results should also be considered as a valid support for the realization of the new Italian gravimetric/altimetric reference network (G0/H0) which is in the construction stage as part of the INGV's “Pianeta Dinamico” project.
Link to the article
#ingv #gnss #earthquakes #eagle #norcia #amatrice
Figure: Absolute gravity meters FG5#238 (in Terni, S. Angelo R. and Popoli) and A10#39 (in L'Aquila and LNGS) used in the 5 sites of the network installed in Central Italy. The map shows the epicenters of seismic events with magnitude ≥ 6.0 (yellow stars) in L'Aquila (2009) and Amatrice -Norcia (2016) and seismicity with magnitude ≥ 2.5, for the periods 1985 – 2008 (yellow dots), 2009 – 2016 (blue points) and 2016 - 2019 (black points). - Figures: Absolute gravimeters FG5#238 (in Terni, S. Angelo R. and Popoli) and A10#39 (in L'Aquila and LNGS) used in the 5 sites of the network installed in Central Italy. The map shows the epicenters of seismic events with a magnitude ≥ 6.0 (yellow stars) in L'Aquila (2009) and Amatrice-Norcia (2016) and the seismicity with a magnitude ≥ 2.5, for the periods 1985 - 2008 (yellow points) , 2009 - 2016 (blue points) and 2016 - 2019 (black points).