Percorrer por autor "Petrosino, Simona"
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- On a planetary forcing of global seismicityPublication . Dumont, Stéphanie; d’Ars, Jean de Bremond; Boulé, Jean-Baptiste; Courtillot, Vincent; Gèze, Marc; Gibert, Dominique; Kossobokov, Vladimir; Mouël, Jean-Louis Le; Lopes, Fernando; Neves, Maria C.; Silveira, Graça; Petrosino, Simona; Zuddas, PierpaoloWe have explored the temporal variability of the seismicity at global scale over the last 124 years, as well as its potential drivers. To achieve this, we constructed and analyzed an averaged global seismicity curve for earthquakes of magnitude equal or greater than 6.0 since 1900. Using Singular Spectrum Analysis, we decomposed this curve and compared the extracted pseudo-cycles with two global geophysical parameters associated with Earth’s tides: length-of-day variations and sea-level changes. Our results reveal that these three geophysical signal curves can be reconstructed up to ∼90% by the sum of up to seven periodic components ranging from 1 to ∼60 years, largely aligned with planetary ephemerides. We discuss these results in the framework of Laplace’s theory, with a particular focus on the phase relationships between seismicity, length-of-day variations, and sea-level changes to further elucidate the underlying physical mechanisms. Finally, integrating observations from seismogenic regions, we propose a possible trigger mechanism based on solid Earth–hydrosphere interactions, emphasizing the key role of water-rock interactions in modulating earthquake occurrence.
- On the link between global volcanic activity and global mean sea levelPublication . Dumont, Stéphanie; Petrosino, Simona; Neves, MariaStudying a large number of volcanic eruptions is a way to decipher general characteristics related to volcano dynamics but also on external forcing influencing it, such as solid Earth and ocean tides. Many studies have tackled this tidal influence on the onset of volcanic eruptions and more generally, on volcanic activity. However, the interplay between this quasi-permanent forcing and volcanic systems is still poorly understood. With the present study, we propose to consider a global viewpoint to address this interaction. We analyzed the number of monthly volcanic eruptions and the global mean sea level between 1880 and 2009 using the Singular Spectrum Analysis time-series analysis technique to evaluate the existence of common periodicities. We found multi-decadal components of similar periodicities present in both time-series which we link to those already recognized in the polar motion. Its multi-decadal variations result in a mass reorganization in the oceans whose associated stress changes may impact processes generating volcanic eruptions worldwide. Our results show the influence of global processes on volcanic activity and open many questions to further investigate these multi-scale interactions.