Unusual seismic activity in 2011 and 2013 at the submarine volcano Rocard, Society hot spot (French Polynesia)

We analyze two seismic events that occurred on 27 May 2011 and 29 April 2013 at the Rocard submarine volcano which overlies the Society hot spot. The Polynesian Seismic Network recorded for the first time unusual associated short-and long-period signals, with perfectly monochromatic (0.0589 Hz) Rayl...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Talandier, Jacques, Hyvernaud, Olivier, Maury, Rene
Format: Article in Journal/Newspaper
Language:English
Published: Amer Geophysical Union 2016
Subjects:
Online Access:https://archimer.ifremer.fr/doc/00639/75083/75614.pdf
https://doi.org/10.1002/2016GL068342
https://archimer.ifremer.fr/doc/00639/75083/
Description
Summary:We analyze two seismic events that occurred on 27 May 2011 and 29 April 2013 at the Rocard submarine volcano which overlies the Society hot spot. The Polynesian Seismic Network recorded for the first time unusual associated short-and long-period signals, with perfectly monochromatic (0.0589 Hz) Rayleigh wave trains of long period and duration. None of the numerous observations of long-period (10-30 s) signals previously associated with volcanic activity in Japan, Italy, Mexico, Indonesia, Antarctica, and the Hawaiian Islands have the characteristics we observed at Rocard. We propose a tentative model for these unusual and rather enigmatic signals, in which the movement of lava excited the resonance of a shallow open conduit under a high hydrostatic pressure of similar to 400 bars.