On the comparison of strain measurements from fibre optics with a dense seismometer array at Etna volcano (Italy)
<p>We demonstrate the capability of distributed acoustic sensing (DAS) to record volcano-related dynamic strain at Etna (Italy). In summer 2019, we gathered DAS measurements from a 1.5 km long fibre in a shallow trench and seismic records from a conventional dense array comprised of 26 broadba...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2021-04-01
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| Series: | Solid Earth |
| Online Access: | https://se.copernicus.org/articles/12/993/2021/se-12-993-2021.pdf |
| Summary: | <p>We demonstrate the capability of distributed acoustic sensing (DAS) to record volcano-related dynamic strain at Etna (Italy). In summer 2019, we gathered DAS measurements from a 1.5 km long fibre in a
shallow trench and seismic records from a conventional dense array
comprised of 26 broadband sensors that was deployed in Piano delle Concazze close to
the summit area. Etna activity during the acquisition period gives the
extraordinary opportunity to record dynamic strain changes (<span class="inline-formula">∼</span> 10<span class="inline-formula"><sup>−8</sup></span> strain) in correspondence with volcanic events. To validate the DAS strain
measurements, we explore array-derived methods to estimate strain changes
from the seismic signals and to compare with strain DAS signals. A general
good agreement is found between array-derived strain and DAS measurements
along the fibre optic cable. Short wavelength discrepancies correspond with
fault zones, showing the potential of DAS for mapping local perturbations of
the strain field and thus site effect due to small-scale heterogeneities
in volcanic settings.</p> |
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| ISSN: | 1869-9510 1869-9529 |