EGU2020-11381, updated on 23 Jan 2024
https://doi.org/10.5194/egusphere-egu2020-11381
EGU General Assembly 2020
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Detection and characterization of microseismicity and its relation with fluids at the Irpinia Near Fault Observatory

Gaetano Festa1, Matteo Picozzi1, Guido Maria Adinolfi1, Alessandro Caruso1, Simona Colombelli1, Grazia De Landro1, Luca Elia1, Rosario Riccio1, Antonio Scala1, Mariano Supino2, and Aldo Zollo1
Gaetano Festa et al.
  • 1Università di Napoli Federico II, Physics, Napoli, Italy (gaetano.festa@unina.it)
  • 2Institut de Physique du Globe de Paris, Paris, France

The Irpinia Near Fault Observatory (NFO) is an EPOS infrastructure located in the Campania-Lucania Region (Southern Italy). Its goal is to characterize the microseismicity and to understand the underlying chemical and physical processes occurring along the fault systems that can potentially generate large earthquakes in the area. The Irpinia NFO is currently composed of ISNet – Irpinia Seismic Network, with associated products and services. ISNet is a local network of 32 accelerometric, short-period and broad band stations, that cover the seismogenic areas related to the main earthquakes that occurred in the region in the last centuries, including the 23 November 1980 , Ms = 6.9 event.  Also, ISNet provides real-time analysis and it represents the prototype network for the testing of early warning systems in Italy.

Here we present tools and techniques to accurately locate and characterize the seismicity within the Observatory. Accurate event detection of weak signals from small magnitude events is based on the coherence of arrival times and migration techniques. This method is then coupled with advanced picking and double differences techniques to accurately locate events with a sub-kilometric scale resolution. Source parameters are thus computed inverting the displacement amplitude spectrum, with a probabilistic approach based on the conjunction of states of information in the data and model spaces. This technique is able to automatically rule out unconstrained solutions, while accounting for correlation among parameters. Source location and characterization is here used to investigate the role of the fluids in the region embedding the fault systems; space and time changes in the medium properties or in the source parameters can be used to detect a deviation from the present mechanical state of the faults owing to changes in fluid pore pressure and migration.

Finally, local dense arrays are used here to improve our capability to detect events within the noise level and to move from a point-source to an extended source description of small events in the area.

How to cite: Festa, G., Picozzi, M., Adinolfi, G. M., Caruso, A., Colombelli, S., De Landro, G., Elia, L., Riccio, R., Scala, A., Supino, M., and Zollo, A.: Detection and characterization of microseismicity and its relation with fluids at the Irpinia Near Fault Observatory, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11381, https://doi.org/10.5194/egusphere-egu2020-11381, 2020.