Nevado del Ruiz Volcano (Colombia): 
A 3D Model Combining Geological and Geophysical Information

Abstract

The Nevado del Ruiz Volcano (NRV) in Colombia is a high-enthalpy geothermal system currently explored for its potential for energy production. We present a case study in the development of a 3D model of the NRV that integrates legacy geological, geochemical and seismic data with modern, newly acquired MT geophysical data. The initial geological interpretation is supported both by surface geology and published interdisciplinary conceptual models. Lithological and structural correlations in 3D space were obtained by using a potential field method. Inversions of geophysical data sets, such as magnetotellurics, were used to further constrain the model. The magnetotelluric dataset was acquired during a fieldwork campaign in 2013. For the first time, a full 3D geological characterisation of this volcanic system is available, integrating and honouring the existing body of information. The spatial relationships proposed in the new model expand the current knowledge about the plumbing and hydrothermal system of the volcano. Magnetotelluric data supports the identification of an independent heat source and a convective hydrothermal system in the W flank of the volcano. Future improvements include the addition of seismic data analysis, via implementation of receiver functions.