%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Bean, C. J.
%A De Barros, L.
%A Lokmer, I.
%A Métaxian, Jean-Philippe
%A Brien, G. O.
%A Murphy, S.
%T Long-period seismicity in the shallow volcanic edifice formed from slow-rupture earthquakes
%D 2014
%L fdi:010061435
%G ENG
%J Nature Geoscience
%@ 1752-0894
%K ITALIE ; COSTA RICA ; PEROU
%M ISI:000328962700023
%N 1
%P 71-75
%R 10.1038/ngeo2027
%U https://www.documentation.ird.fr/hor/fdi:010061435
%> https://www.documentation.ird.fr/intranet/publi/2014/01/010061435.pdf
%V 7
%W Horizon (IRD)
%X Forecasting of volcanic eruptions is still inadequate, despite technological advances in volcano monitoring. Improved forecasting requires a deeper understanding of when unrest will lead to an actual eruption. Shallow, long-period seismic events often precede volcanic eruptions and are used in forecasting. They are thought to be generated by resonance in fluid-filled cracks or conduits, indicating the presence of near-surface magmatic fluids. Here we analyse very-high-resolution seismic data from three active volcanoes-Mount Etna in Italy, Turrialba Volcano in Costa Rica and Ubinas Volcano in Peru-measured between 2004 and 2009. We find that seismic resonance is dependent on the wave propagation path and that the sources for the long-period seismic waves are composed of short pulses. We use a numerical model to show that slow-rupture failure in unconsolidated volcanic materials can reproduce all key aspects of these observations. Therefore, contrary to current interpretations, we suggest that short-duration long-period events are not direct indicators of fluid presence and migration, but rather are markers of deformation in the upper volcanic edifice. We suggest that long-period volcano seismicity forms part of the spectrum between slow-slip earthquakes and fast dynamic rupture, as has been observed in non-volcanic environments.
%$ 066