Application of the Monopole Source to Quantify Explosive Flux during Vulcanian Explosions at Sakurajima Volcano (Japan)

Introduction to an Open Community Infrasound Dataset from the Actively Erupting Sakurajima Volcano, Japan

“…There does not seem to be a robust correlation between the two parameters, as has been suggested for some other volcanoes (e.g., McNutt et al, 2013). The paper by Johnson and Miller (2014) examines the relatively poor scaling of infrasound amplitude and plume height.…”

“…This introductory manuscript provides an overview to the data collected and points out some general observations relevant to the broader seismo-acoustic and volcanology communities. Johnson and Miller (2014) apply waveform modeling to estimate volume of erupted material associated with the Sakurajima explosions. Kim and Lees (2014) use novel graphical processing unit-based finite difference time domain processing to investigate 3D infrasound propagation and source localization.…”

Acoustic Characterization of Explosion Complexity at Sakurajima, Karymsky, and Tungurahua Volcanoes

“…Commonly, the discrete explosion signals are simply called "explosions" in the volcano acoustics literature and they have been modeled, using linear equivalent source theory, as acoustic monopoles, that is, sources represented as time-varying mass fluxes (e.g., Woulff and McGetchin, 1976;Firstov and Kravchenko, 1996;Johnson, 2003;Delle Donne and Ripepe, 2012;Johnson and Miller, 2014). However, it is recognized that in many cases these "explosion" waves have nonlinear characteristics (Yokoo and Ishihara, 2007;Garces et al, 2013;Marchetti et al, 2013), and nonlinear effects will increase with increasing overpressure release rate and supersonic ejection velocities (Needham, 2010).…”

Diverse Eruptive Activity Revealed by Acoustic and Electromagnetic Observations of the 14 July 2013 Intense Vulcanian Eruption of Tungurahua Volcano, Ecuador

“…Johnson and Miller (2014) solved this problem by estimating flow rate using equation (4) and detrending to make infrasound pressure and flow rate zero at the end of the signal. Such noise is common in infrasound recordings and is problematic because trends and low frequencies are magnified by inversion, sometimes causing volume flow to be nonzero long after the end of the signal.…”