EGU26-14023, updated on 14 Mar 2026
https://doi.org/10.5194/egusphere-egu26-14023
EGU General Assembly 2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
Poster | Wednesday, 06 May, 08:30–10:15 (CEST), Display time Wednesday, 06 May, 08:30–12:30
 
Hall X2, X2.133
The MARGE magnetotelluric array in Central Italy: measurements and modelling perspectives for geomagnetic applications and geoelectric hazard assessment 
Paola De Michelis1, Marianna Balasco2, Igino Coco1, Michele De Girolamo1, Manuele Di Persio3, Fabio Giannattasio1, Cesidio Gizzi3, Valerio Materni1, Luca Miconi1, Massimo Miconi1, Giovanna Lucia Piangiamore4, Giulia Pigniatiello5, Gerardo Romano5, Valentina Romano1, Lucia Santarelli3, Vincenzo Sapia1, Sabina Spadoni1, Roberta Tozzi1, Simona Tripaldi5, and Agata Siniscalchi5
Paola De Michelis et al.
  • 1Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy (paola.demichelis@ingv.it)
  • 2Istituto di Metodologie per l’Analisi Ambientale (IMAA), Consiglio Nazionale delle Ricerche, Tito Scalo, Italy,
  • 3Istituto Nazionale di Geofisica e Vulcanologia, L'Aquila, Italy
  • 4Istituto Nazionale di Geofisica e Vulcanologia, Lerici, Italy
  • 5Dipartimento di Scienze della Terra e Geoambientali, Università degli Studi di Bari, "Aldo Moro", Bari, Italy

Rapid variations of the geomagnetic field represent both a resource and a hazard for modern technological systems. While geomagnetic observations support a wide range of applications, from navigation to positioning, storm-time magnetic disturbances can induce strong geoelectric fields at the Earth’s surface, driving geomagnetically induced currents (GICs) that threaten power grids and other grounded infrastructures. Accurate modelling of these ground effects critically depends on realistic representations of the Earth’s electrical conductivity.

In this contribution, we present the first results from the MARGE (Magnetotelluric ARray in Central Italy for GEoelectric hazard assessment) project, a measurement-driven initiative designed to provide the geophysical foundation for geomagnetic applications related to space-weather impacts. MARGE consists of a broadband and long-period magnetotelluric (MT) array deployed on a ~50 km grid across central Italy, a region characterized by strong lateral conductivity contrasts associated with active tectonics, sedimentary basins, volcanic provinces, and land–sea boundaries.

We describe the survey design, instrumentation, and data processing strategy, and assess the quality of 20 MT soundings acquired between 2023 and 2025. More than 75% of the sites yield good to excellent impedance estimates over periods from 10-3 to 104 s. Apparent resistivity, phase curves, and phase tensor analysis reveal pronounced spatial and depth-dependent variability of the electrical structure, highlighting the inadequacy of simplified one-dimensional conductivity models for geomagnetic applications in this region.

These first measurement-based results demonstrate the feasibility of constructing a realistic 3-D conductivity framework for Italy and represent a key step toward physics-based modelling of storm-time geoelectric fields. MARGE provides essential input for future GIC simulations and contributes to improving the reliability of geomagnetic-field-based applications and risk mitigation strategies.

How to cite: De Michelis, P., Balasco, M., Coco, I., De Girolamo, M., Di Persio, M., Giannattasio, F., Gizzi, C., Materni, V., Miconi, L., Miconi, M., Piangiamore, G. L., Pigniatiello, G., Romano, G., Romano, V., Santarelli, L., Sapia, V., Spadoni, S., Tozzi, R., Tripaldi, S., and Siniscalchi, A.: The MARGE magnetotelluric array in Central Italy: measurements and modelling perspectives for geomagnetic applications and geoelectric hazard assessment , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14023, https://doi.org/10.5194/egusphere-egu26-14023, 2026.