Cáceres, Francisco and Wadsworth, Fabian B. and Scheu, Bettina and Colombier, Mathieu and Madonna, Claudio and Cimarelli, Corrado and Hess, Kai-Uwe and Kaliwoda, Melanie and Ruthensteiner, Bernhard and Dingwell, Donald B. (2020) 'Can nanolites enhance eruption explosivity?', Geology., 48 (10). pp. 997-1001.
Degassing dynamics play a crucial role in controlling the explosivity of magma at erupting volcanoes. Degassing of magmatic water typically involves bubble nucleation and growth, which drive magma ascent. Crystals suspended in magma may influence both nucleation and growth of bubbles. Micron- to centimeter-sized crystals can cause heterogeneous bubble nucleation and facilitate bubble coalescence. Nanometer-scale crystalline phases, so-called “nanolites”, are an underreported phenomenon in erupting magma and could exert a primary control on the eruptive style of silicic volcanoes. Yet the influence of nanolites on degassing processes remains wholly uninvestigated. In order to test the influence of nanolites on bubble nucleation and growth dynamics, we use an experimental approach to document how nanolites can increase the bubble number density and affect growth kinetics in a degassing nanolite-bearing silicic magma. We then examine a compilation of these values from natural volcanic rocks from explosive eruptions leading to the inference that some very high naturally occurring bubble number densities could be associated with the presence of magmatic nanolites. Finally, using a numerical magma ascent model, we show that for reasonable starting conditions for silicic eruptions, an increase in the resulting bubble number density associated with nanolites could push an eruption that would otherwise be effusive into the conditions required for explosive behavior.
|Full text:||(VoR) Version of Record|
Available under License - Creative Commons Attribution.
Download PDF (1352Kb)
|Publisher Web site:||https://doi.org/10.1130/G47317.1|
|Publisher statement:||© 2020 The Authors. Gold Open Access: This paper is published under the terms of the CC-BY license.|
|Date accepted:||11 May 2020|
|Date deposited:||23 October 2020|
|Date of first online publication:||19 June 2020|
|Date first made open access:||23 October 2020|
Save or Share this output
|Look up in GoogleScholar|