Modelling the macroscopic behavior of Strombolian explosions at Erebus volcano

• Published in: Physics of the Earth and Planetary Interiors
• Language: English
• Published: Elsevier 2011
• Subjects: Strombolian explosions; Erebus volcano; Diffusion; Lava Lake; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/2262/53007; https://doi.org/10.1016/j.pepi.2009.05.003

Abstract We analyze seismic signals associated with the Strombolian explosion quakes at Erebus volcano (Antarctica), examining the high-frequency (>0.5Hz) portion of the spectrum. We consider recordings relative to two time periods during the years 2005 and 2006. Cross-correlation analysis allows us to distinguish three classes of events. Spectral properties and polarization analysis provide evidence of a very complex volcanic structure. We conduct analyses to elucidate the macroscopic dynamic system associated with the explosions. The distribution of the times between successive explosion-quakes is exponential, implying a Poissonian process as observed at Stromboli volcano but on a different time scale. The sequence of the occurrence of the explosions can be described by classical intermittency. A coalescence Chandrasekar-Landau mean-field model reproduces gas bubble sizes comparable with those observed at the lava lake surface. Finally, the classical equation for the ascent of gas bubbles is generalized by adding a diffusive process. This model provides ascent velocities depending on the bubble radius: for gas bubbles greater than a few centimeters, variation in ascent velocity due to diffusion becomes negligible and the ascent velocity appears to be governed primarily by buoyancy. correspondance: Corresponding author at: Dipartimento di Matematica e Informatica, Universita di Salerno, Via Ponte Don Melillo, Fisciano (SA) 84084 Italia Tel.: [phone]; fax: [phone]. (Falanga, M.) [e-mail] (Falanga, M.) Dipartimento di Matematica e Informatica--> , Universita di Salerno--> , Via Ponte Don Melillo--> , 84084 Fisciano (SA)--> , Italia--> - (De Lauro, E.) Dipartimento di Matematica e Informatica--> , Universita di Salerno--> , Via Ponte Don Melillo--> , 84084 Fisciano (SA)--> , Italia--> - (De Martino, S.) INFN--> , Gruppo collegato di Salerno--> , Via S. Allende--> , 84081 Baronissi (SA)--> , Italia--> - (De Martino, S.) Dipartimento di Fisica--> , Universita di Salerno--> , Via S. Allende--> , 84081 Baronissi (SA)--> , Italia--> - (Falanga, M.) INFN--> , Gruppo collegato di Salerno--> , Via S. Allende--> , 84081 Baronissi (SA)--> , Italia--> - (Falanga, M.) Dipartimento di Matematica e Informatica--> , Universita di Salerno--> , Via Ponte Don Melillo--> , 84084 Fisciano (SA)--> , Italia--> - ITALY (Falanga, M.) Dipartimento di Matematica e Informatica--> , Universita di Salerno--> , Via Ponte Don Melillo--> , 84084 Fisciano (SA)--> , Italia--> - (Palo, M.) ITALY Received: 2008-10-30 Revised: 2009-04-03 Accepted: 2009-05-01