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

• Published in: Geophysical research letters Vol. 43; no. 9; pp. 4247 - 4254
• Main Authors: Talandier, Jacques, Hyvernaud, Olivier, Maury, René C.
• Format: Journal Article
• Language: English
• Published: Washington John Wiley & Sons, Inc 16.05.2016; American Geophysical Union
• Subjects: Conduits; Duration; Earth Sciences; Earthquakes; French Polynesia; Hot spots; Hot spots (geology); Hydrostatic pressure; Lava; monochromatic Rayleigh waves; Rayleigh waves; Rocard active volcano; Sciences of the Universe; Seismic activity; Seismic analysis; Seismic phenomena; Society; Society hot spot; submarine magma transfer; Submarine volcanoes; Transit; Volcanic activity; Volcanoes; Wave packets; Wave trains; Italy; Mexico; Antarctica; Japan; Indonesia; French Polynesia; PS, Antarctica; MED, Italy; ISE, Pacific, French Polynesia; INW, Japan; Society hot spot; submarine magma transfer; monochromatic Rayleigh waves; Rocard active volcano; French Polynesia
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1002/2016GL068342

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 ~400 bars. Key Points Unusual signals, with monochromatic Rayleigh wave trains of long duration, are attributed to the transit of lava in a shallow opened conduit Under a high hydrostatic pressure of ~400 bars, the transit of lava excited the resonance of this conduit Such identical seismic events occurred on 27 May 27 2011 and 29 April 2013 at the submarine volcano Rocard, Society hot spot