Editorial: exploring volcanic paroxysmal explosive activity from magma source to ground and atmosphere

Editorial on the Research Topic
Exploring Volcanic Paroxysmal Explosive Activity From Magma Source to Ground and Atmosphere

Volcanic paroxysmal explosive activity has enormous potential destructive power and usually causes widespread damages to the Society ( NAS–National Academies of Sciences Engineering Medicine, 2017 ). Serious problems can occur even during explosive activity related to modest eruptions, such as the case of the 2010 Eyiafjallajokull eruption in Iceland that paralyzed the air traffic in the European continent and in the North Atlantic. In general, a crucial issue, and also an intriguing challenge, is to evaluate the state of the preparatory phase leading to an eruption. It is important to understand the characteristics of the volcano state both for the long-term preparatory phases, usually anticipating the strongest eruptions, and also for the medium- to short-term phases preceding the more frequent and usually less powerful eruptions, but with more immediate consequences.

The first paper of the collection gives an overview of the long-term dynamics of the volcanic paroxysmal activity at andesitic and dacitic volcanoes during 1960–2010 ( Zobin ). In this study two groups of eruptions with VEI 5–6 and VEI 3–4 were considered. The main tool used was the seismic monitoring of the volcanoes. The eruptions of the first group are characterized by long periods of quiescence (longer than 120 years) and precursory volcano tectonic seismic swarms. The second group develops in more individual styles, each typical of a certain volcano. The study suggests that the eruptions with higher VEI are related to a plugged magmatic conduit, whereas eruptions with lower VEI are usually associated to open conduits.

As a specific case of volcano producing frequent explosive eruptions with low VEI, the second paper of this Research Topic considers the Etna eruptive activity during 2009–2017 by using ground deformation and strain data ( Aloisi et al. ). Etna volcano was characterized over this period by an incredible lively eruptive activity. This comprised 44 lava fountain episodes from the New South East Crater, two sequences of lava fountains from the Voragine crater, as well as some periods of summit effusive activity with a more prolonged supply of lava flows. The authors produced a complete representation of the different sources that characterized the different periods both in the medium-term (i. e., the preparatory phases showing inflation and the eruptive phases showing deflation) and in the short-term (i. e., the fast discharge associated with eruptive events).

Favalli, M., Fornaciai, A., Nannipieri, L., Harris, A., Calvari, S., and Lormand, C. (2018). UAV-based remote sensing surveys of lava flow fields: a case study from Etna’s 1974 channel-fed lava flows. Bull. Volcanol. 80: 29. doi: 10. 1007/s00445-018-1192-6

NAS–National Academies of Sciences Engineering and Medicine (2017). Volcanic Eruptions and Their Repose, Unrest, Precursors, and Timing . Washington, DC: The National Academies Press.

Neri, M., De Maio, M., Crepaldi, S., Suozzi, E., Lavy, M., Marchionatti, F., et al. (2017). Topographic maps of mount Etna summit crater’s area, 14 december 2015. J. Maps 13, 674–683. doi: 10. 1080/17445647. 2017. 1352041

Newhall, C. G., and Self, S. (1982). The volcanic explosivity index (VEI): an estimate of explosive magnitude for historical volcanism. J. Geophys. Res . 87, 1231–1238. doi: 10. 1029/JC087iC02p01231