Reología de los flujos de lava de cada fase eruptiva del volcán el reventador desde el 2002 hasta el 2018.

Abstract

The work focuses on the analysis of the lava flows emitted by this volcano, which correspond to 81 flows already emplaced and 1 in continuous advance, of compositions between basaltic andesites and trachyandesites. The project focused on determining the rheological value of fluids with more andesitic compositions, not Newtonian along two lavas LF5 and LF9 emitted in 2005 and 2007 respectively, to understand their dynamism and heterogeneity. Also, the rheology of the eruptive phases using a representative sample of the six existing phases to observe their rheological variation throughout the eruptive activity of the volcano. The calculation of the rheological parameters corresponding to the viscosity and yield strength was carried out using two different methodologies: based on its morphology and based on its composition. Rheological results from the samples indicate variation along the flow, inferring that there is a slightly higher value as the sample is closer to the lava front. Also, analyzing the rheology over time, the presence of a slight evolution is observed; the viscosity parameters increase progressively to the most current phase. It can be contrasted with the extent of lava flows in that period, which have a smaller displacement with respect to the initial phases since 2002. It was observed that the yield strength increases as it approaches the lava front and between eruptive phases is characterized by ups and downs.