17:15 〜 18:45
[MIS04-P05] Geochemical monitoring in a multidisciplinary scientific approach: toward the Near Fault Observatories in Italy
キーワード：Pre-earthquake processes, Geochemistry, Degassing, Groundwater
Rock deformation, faulting and seismicity are controlled by different and variable multi-scale chemical-physical processes. Understanding these processes is of crucial importance for a better comprehension of the mechanisms related to the genesis of earthquakes. It requires a multidisciplinary approach, from geochemical to geophysical topics, as well as the availability of multidisciplinary long-term series of dataset coupled to specific investigations at local and regional scale to produce multidisciplinary 3D models that allow interpreting the long-term series of dataset.
With this aim the National Institute of Geophysics and Volcanology created the Alto Tiberina Near Fault Observatory (TABOO-NFO) in the north of Apennine (Italy), a state-of-the-art monitoring infrastructure for studying the deformation processes active along a crustal fault system dominated by the Alto Tiberina Fault (ATF) (Chiaraluce et al., 2014). TABOO-NFO is a multidisciplinary monitoring infrastructure composed of an array of seismic, geodetic, strain, and geochemical sensors for physical-chemical parameters in groundwater coupled with Rn and CO2 flux monitoring stations (Chiaraluce et al., 2022; Caracausi et al., 2023).
TABOO is part of the Near Fault Observatories (NFOs) community, one of the European Plate Observing System (EPOS, http://www.epos-eu.org) that today consist of six research infrastructures operating in regions characterized by high seismic hazard (Chiaraluce et al., 2022).
In Italy, it also exists the Irpinia NFO (central Apennine) and other areas, which extend further to south, throughout the central and southern Apennines have got the required characteristics for a suitable candidate as NFO. In fact, the entire Apennine arc hosts active faults each of which delimits a circumscribed and well-defined area characterized by relatively high seismicity rates.
In addition, the seismicity along the Apennine is correlated with over-pressurized fluids trapped in crustal layers (Miller et al., 2004) and gaseous manifestations at the surface that emit large amounts of CO2 in atmosphere (e.g., Chiodini et al., 2004). Therefore, besides the undergoing tectonic stress acting in the crust, fluids play an active role in the processes of earthquakes nucleation. In fact, the increase of the fluid pore pressure in both the fault core and the damage zone contribute to seismicity. On this way, during the last years, great attention has been posed to investigate the relationships between fluid circulation in crustal layers and tectonic stress by conducting specific geochemical investigations, at the regional and local scales, all along the Italian Appenine. These investigations allowed to identify some interesting relationships between seismicity, groundwater circulations and soil gas emissions (Buttitta et al., 2023). In this framework, the central-southern Apennine areas represents a natural laboratory to investigate the relationship between degassing, tectonic crustal stress and then seismicity.
These preliminary results are allowing to select some regions along the Apennine suitable to install a network of new generation geochemical instrumentations to continuously monitor the physical-chemical parameters of groundwater from natural springs and boreholes and the CO2 flux from soils close to the CO2-rich gas emissions. According to the example of the TABOO NFO, the preferential regions are those where it exists at least a network of seismic and GPS stations in order to create multidisciplinary long time data series that can combined to challenge the understanding of the earthquakes nucleation processes and the relationship between fluids, seismicity patterns and faulting.
References
Buttitta et al., 2023, Science of the Total Environment 897, 165367,
Caracausi A. et al., 2023 Frontiers in Earth Science, DOI 10.3389/feart.2023.1172643.
Chiaraluce, L. et al., 2014 Ann. Geophys. 57 (3). doi:10.4401/ag-6426.
Chiaraluce et al., (2022)., Annals of Geophysics, 65, 3, DM316, 2022; doi:10.4401/ag-8778.
Chiodini et al., 2004, Geophys. Res. Lett. 31. https://doi.org/10.1029/2004GL019480.
Miller et al., 2004, Nature, 427, 724–727. https:// doi.org/10.1038/nature02251.
With this aim the National Institute of Geophysics and Volcanology created the Alto Tiberina Near Fault Observatory (TABOO-NFO) in the north of Apennine (Italy), a state-of-the-art monitoring infrastructure for studying the deformation processes active along a crustal fault system dominated by the Alto Tiberina Fault (ATF) (Chiaraluce et al., 2014). TABOO-NFO is a multidisciplinary monitoring infrastructure composed of an array of seismic, geodetic, strain, and geochemical sensors for physical-chemical parameters in groundwater coupled with Rn and CO2 flux monitoring stations (Chiaraluce et al., 2022; Caracausi et al., 2023).
TABOO is part of the Near Fault Observatories (NFOs) community, one of the European Plate Observing System (EPOS, http://www.epos-eu.org) that today consist of six research infrastructures operating in regions characterized by high seismic hazard (Chiaraluce et al., 2022).
In Italy, it also exists the Irpinia NFO (central Apennine) and other areas, which extend further to south, throughout the central and southern Apennines have got the required characteristics for a suitable candidate as NFO. In fact, the entire Apennine arc hosts active faults each of which delimits a circumscribed and well-defined area characterized by relatively high seismicity rates.
In addition, the seismicity along the Apennine is correlated with over-pressurized fluids trapped in crustal layers (Miller et al., 2004) and gaseous manifestations at the surface that emit large amounts of CO2 in atmosphere (e.g., Chiodini et al., 2004). Therefore, besides the undergoing tectonic stress acting in the crust, fluids play an active role in the processes of earthquakes nucleation. In fact, the increase of the fluid pore pressure in both the fault core and the damage zone contribute to seismicity. On this way, during the last years, great attention has been posed to investigate the relationships between fluid circulation in crustal layers and tectonic stress by conducting specific geochemical investigations, at the regional and local scales, all along the Italian Appenine. These investigations allowed to identify some interesting relationships between seismicity, groundwater circulations and soil gas emissions (Buttitta et al., 2023). In this framework, the central-southern Apennine areas represents a natural laboratory to investigate the relationship between degassing, tectonic crustal stress and then seismicity.
These preliminary results are allowing to select some regions along the Apennine suitable to install a network of new generation geochemical instrumentations to continuously monitor the physical-chemical parameters of groundwater from natural springs and boreholes and the CO2 flux from soils close to the CO2-rich gas emissions. According to the example of the TABOO NFO, the preferential regions are those where it exists at least a network of seismic and GPS stations in order to create multidisciplinary long time data series that can combined to challenge the understanding of the earthquakes nucleation processes and the relationship between fluids, seismicity patterns and faulting.
References
Buttitta et al., 2023, Science of the Total Environment 897, 165367,
Caracausi A. et al., 2023 Frontiers in Earth Science, DOI 10.3389/feart.2023.1172643.
Chiaraluce, L. et al., 2014 Ann. Geophys. 57 (3). doi:10.4401/ag-6426.
Chiaraluce et al., (2022)., Annals of Geophysics, 65, 3, DM316, 2022; doi:10.4401/ag-8778.
Chiodini et al., 2004, Geophys. Res. Lett. 31. https://doi.org/10.1029/2004GL019480.
Miller et al., 2004, Nature, 427, 724–727. https:// doi.org/10.1038/nature02251.