Autor: |
Stefania Tarantino, Piero Poli, Nicola D’Agostino, Maurizio Vassallo, Gaetano Festa, Gerardo Ventafridda, Aldo Zollo |
Jazyk: |
angličtina |
Rok vydání: |
2024 |
Předmět: |
|
Zdroj: |
Nature Communications, Vol 15, Iss 1, Pp 1-10 (2024) |
Druh dokumentu: |
article |
ISSN: |
2041-1723 |
DOI: |
10.1038/s41467-024-54094-4 |
Popis: |
Abstract Pump-probe experiments investigate the strain sensitivity of crustal elastic properties, showing nonlinear variations during the strain cycle. In the laboratory, pre-seismic reductions in seismic velocity indicate that asperity contacts within the fault zone begin to fail before the macroscopic frictional sliding. The recognition of such effects in natural seismic-cycles has been challenging. Here we exploit seasonal hydrological strains, performing a natural analogue to a quasi-static laboratory pump-probe experiment to investigate the nonlinear strain sensitivity of crustal rocks and its role in seismic failure along the tectonically-active Irpinia Fault System (Southern Italy). By comparing 14-years-long series of spring discharge, strain, seismic velocity variations and earthquakes rate, we find that seismicity peaks during maximum hydrological forcing and minimum seismic velocity. Seasonal strains of ~10−6 are required for both earthquake triggering and significant nonlinearity effects arising from modulus reduction. We suggest that, for faults in a critical state, cyclical softening may lead to failure and seasonal seismicity. |
Databáze: |
Directory of Open Access Journals |
Externí odkaz: |
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