Long-range acoustic observations of the Eyjafjallajökull eruption, Iceland, April-May 2010

Abstract

The April–May 2010 summit eruption of Eyjafjallajökull, Iceland, was recorded by 14 atmospheric infrasound sensor arrays at ranges between 1,700 and 3,700 km, indicating that infrasound from modest‐size eruptions can propagate for thousands of kilometers in atmospheric waveguides. Although variations in both atmospheric propagation conditions and background noise levels at the sensors generate fluctuations in signal‐to‐noise ratios and signal detectability, array processing techniques successfully discriminate between volcanic infrasound and ambient coherent and incoherent noise. The current global infrasound network is significantly more dense and sensitive than any previously operated network and signals from large volcanic explosions are routinely recorded. Because volcanic infrasound is generated during the explosive release of fluid into the atmosphere, it is a strong indicator that an eruption has occurred. Therefore, long‐range infrasonic monitoring may aid volcanic explosion detection by complementing other monitoring technologies, especially in remote regions with sparse ground‐based instrument networks.

Automated detection and cataloging of global explosive volcanism using the International Monitoring System infrasound network

“…Our method is based loosely on the methods of Landès et al [2012] and Matoza et al [2011b]. We take advantage of the assumed signal characteristics of infrasound from sustained explosive volcanic eruptions (section 2), employing long-duration (e.g., 2-day) detection averaging to give more weight to sustained signals and achieve robustness with respect to assumed celerity.…”

“…An initial burst of infrasound from this event was recorded from 14 to 15 April 2010, with the major long-duration infrasound recorded from 18 April to 20 May 2010 [Matoza et al, 2011b]. We only use IMS stations in this study, but additional data from regional infrasound array networks (not used here) greatly enhance the detection capability of this event [Matoza et al, 2011b]. Figure 9 shows the application of this method using the time 18-20 April 2010 for G d and 8-18 April 2010 for G p .…”

“…We also note that Landès et al [2012] and Matoza et al [2011b] normalized the contributions from each station such that each station contributes equally to the grid function. We avoid such a normalization here as our method relies on emphasizing the large number of detections on stations closest to the source.…”

“…We exploit the following a priori assumed characteristics of volcanic infrasound, based on knowledge from previous studies [e.g., Fee et al, 2010b;Matoza et al, 2011aMatoza et al, , 2011bDabrowa et al, 2011; 1. Explosive volcanic eruptions represent fixed point source locations.…”

A New Journal Serving the Infrasound Community

“…Signals from this event were recorded by infrasound arrays after circling the globe twice [2] and by the Transportable Array. Another recent event that was recorded by a large number of infrasound stations was the eruption of Eyjafjallajökull, Iceland [3].…”