DOI: 10.5281/zenodo.5575971
title: Mechanical properties of Nevado del Ruiz - St. Isabel volcanoes

description: <strong>Description and structure of the data </strong><br> Data of static and dynamic mechanical material properties organized in 6 columns. The first three columns contain the position in UTM coordinates (UTM zone 18N): easting, northing, and depth (positive numbers refer to points above the mean sea level and negative numbers to points below the sea level). The last three columns contain Poisson’s dynamic ratio, Young’s static modulus, and density. The first row of the file is dedicated to the following header: UTM_x (m), UTM_y (m), Z (m), Poisson_dy, Young_st (GPa), density (kg/m^3) <strong>Static and dynamic mechanical elastic properties</strong> The dynamic elastic properties are calculated from P-wave (Vp) and S-wave (Vs) tomographic velocities, derived from the seismicity recorded by the Colombian Geological Survey - Volcanological and Seismological Observatory of Manizales (OVSM) between January 1st, 2016 and February 19, 2019. Empirical relationships are used for the conversion into static values (Hautmann et al., 2013; Wang, 2000). The relationship between dynamic Young’s modulus (\(E_{dy}\)) and shear wave velocity, Vs, inferred from the tomography (Telford et al., 1976) is<strong> <strong>\(E_{dy} = 2\rho\left( 1+\nu_{dy} \right)V_{s}^2\)</strong></strong> where ρ is density (Jaeger, 2007), defined through the Nafe-Drake empirical curve (Brocher, 2005) that describes the density (g/cm3) as function of Vp between 1.5 km/sec and 8.5 km/sec: \(\varrho=1.6612V_{p}-0.4721{V}_{p}^{2}+0.0671{V}_{p}^{3}-0.0043{V}_{p}^{4}+0.000106{V}_{p}^{5}\) and the dynamic Poisson’s modulus, \(\nu_{dy}\), is calculated from the relationship of Vp and Vs, as in the case of an isotropic medium for lack of better information (i.e. borehole tests), with the following formula (Guéguen and Palciauskas, 1994; Heap et al., 2014): \({\nu}_{dy}=\frac{V_{p}^2-2V_{s}^2}{2(V_{p}^2-V_{s}^2)}\) The values of the dynamic Young’s modulus derived, \(E_{dy}\), increase from 12 GPa to 135 GPa, while the range of dynamic Poisson’s ratio values is between 0.17 and 0.30. In order to convert the dynamic values of the Young modulus into static values, we apply a standard empirical relationship (Wang, 2000): \(E_{st} = 0.415\times E_{dy} (GPa) - 1.056\) <br> The resulting values for \(E_{st}\) of the upper crust is from 5 GPa to 56 GPa. <strong>References</strong> <strong>Brocher</strong>, T.M., 2005. Empirical relations between elastic wavespeeds and density in the Earth’s crust. Bulletin of the Seismological Society of America 95, 2081–2092. https://doi.org/10.1785/0120050077<br> <strong>Guéguen</strong>, Y., Palciauskas, V., 1994. Introduction to the Physics of Rocks, Princeton University Press. ed. Princeton, New Jersey.<br> <strong>Hautmann</strong>, S., Hidayat, D., Fournier, N., Linde, A.T., Sacks, I.S., Williams, C.P., 2013. Pressure changes in the magmatic system during the December 2008/January 2009 extrusion event at Soufrière Hills Volcano, Montserrat (W.I.), derived from strain data analysis. Journal of Volcanology and Geothermal Research 250, 34–41. https://doi.org/10.1016/j.jvolgeores.2012.10.006<br> <strong>Heap</strong>, M.J., Baud, P., Meredith, P.G., Vinciguerra, S., Reuschlé, T., 2014. The permeability and elastic moduli of tuff from Campi Flegrei, Italy: implications for ground deformation modelling. Solid Earth 5, 25–44. https://doi.org/10.5194/se-5-25-2014<br> <strong>Telford</strong>, W.M., Geldart, L.P., Sheriff, R.E., Keys, D.A., 1976. Applied Geophysics. Cambridge University Press, Cambridge.<br> <strong>Wang</strong>, Z., 2000. Dynamic versus static elastic properties of reservoir rocks, in: Seismic and Acoustic Velocities in Reservoir Rocks. Soc. of Explor. Geophys., Tusla, Oklahoma, pp. 531–539. This dataset is one of the results of PICVOLC project. PICVOLC has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 793811.