Velocities in the plume of the 2010 Eyjafjallajökull eruption

Abstract

[1] The eruption of the Icelandic volcano Eyjafjallajökull in the spring of 2010 lasted for 39 days with an explosive phase (14-18 April), an effusive phase (18 April to 4 May) and a phase with renewed explosive activity (5-17 May). Images every 5 s from a camera mounted 34 km from the volcano are available for most of the eruption. Applying the maximum cross-correlation method (MCC) on these images, the velocity structure of the eruption cloud has been mapped in detail for four time intervals covering the three phases of the eruption. The results show that on average there are updrafts in one part of the cloud and lateral motion or downdrafts in another. Even within the updraft part, there are alternating motions of strong updrafts, weak updrafts, and downward motion. These results show a highly variable plume driven by intermittent explosions. The results are discussed in the context of integral plume models and in terms of elementary parcel theory.

Improved optical flow velocity analysis in SO<sub>2</sub> camera images of volcanic plumes – implications for emission-rate retrievals investigated at Mt Etna, Italy and Guallatiri, Chile

“…Luckily, the high resolution of the imaging systems allows us to account for these spatial and temporal fluctuations by directly measuring the projected 2-D velocity fields using optical flow (OF) algorithms (e.g. Krueger et al, 2013, Bjornsson et al, 2013, Peters et al, 2015, Lopez et al, 2015, Stebel et al, 2015, Kern et al, 2015.…”

Mass eruption rates in pulsating eruptions estimated from video analysis of the gas thrust-buoyancy transition—a case study of the 2010 eruption of Eyjafjallajökull, Iceland

“…These bursts are here referred to as "ash pulses". The pulsating behavior was also detected in the velocity profile of the plume (Bjornsson et al 2013) and in the infrasound signature of the eruption (Ripepe et al 2013) and was quantified for 4 May in terms of number of pulses, pulse velocities, and pulse heights by using a thermal camera (Ripepe et al 2013).…”

MeMoVolc consensual document: a review of cross-disciplinary approaches to characterizing small explosive magmatic eruptions

“…Infrasonic array methods are also available to locate the emission in x,y space (Ripepe and Marchetti 2002). Plume front velocities, density and entrainment rates have also been successfully tracked using visible and thermal cameras, as well as radiometers, for a few stronger, ash-rich, buoyant plumes at Stromboli, Santiaguito and Eyjafjallajökull (Patrick 2007;Sahetapy-Engel and Harris 2009;Bjornsson et al 2013;Valade et al 2014) (see Chapter 9 of Harris 2013 for review).…”