EGU22-738, updated on 26 Mar 2022
https://doi.org/10.5194/egusphere-egu22-738
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Fluid migrations and volcanic earthquakes from depolarized ambient noise

Luca De Siena1 and Simona Petrosino2
Luca De Siena and Simona Petrosino
  • 1Institute of Geosciences, Johannes Gutenberg University, Mainz, 55128, Germany.
  • 2Istituto Nazionale di Geofisica e Vulcanologia - Osservatorio Vesuviano

Ambient noise polarizes inside fault zones, yet the spatial and temporal resolution of polarized noise on gas-bearing fluids migrating through stressed volcanic systems is unknown. At Campi Flegrei caldera (Southern Italy), high polarization marks a transfer structure connecting the deforming centre of the caldera to open hydrothermal vents and extensional caldera-bounding faults during periods of low seismic release. Fluids pressurize the Campi Flegrei hydrothermal system, migrate, and increase stress before earthquakes. The loss of polarization (depolarization) of the transfer and extensional structures maps pressurized fluids, detecting fluid migrations after seismic sequences. After recent intense seismicity (December 2019-April 2020), the transfer structure appears sealed while fluids stored in the east caldera have moved further east. Our findings show that depolarized noise has the potential to monitor fluid migrations and earthquakes at stressed volcanoes quasi-instantaneously and with minimum processing.

How to cite: De Siena, L. and Petrosino, S.: Fluid migrations and volcanic earthquakes from depolarized ambient noise, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-738, https://doi.org/10.5194/egusphere-egu22-738, 2022.