Glycerin

Properties keywords:  Newtonian liquid, water soluble, colourless, non-toxic

Analogue keywords: magma mixing, magmatic intrusions

Common names: glycerol, glycerine, propane-1,2,3-triol, 1,2,3-trihydroxypropane, C3H8O3

General Information:  Glycerin is a colourless, odourless, water soluble, viscous liquid that is inexpensive, readily available and easy to clean.

Glycerin is a sugar alcohol compound and can be synthetic or derived from plants/animals.  It is used in the pharmaceutical and food industries and is a common sugar substitute.

Properties

Glycerin is a low viscosity Newtonian fluid that is readily mixed with water and can be dyed to allow for easy observation during experiments.  Pure glycerin has a density of 1260 kg m-3 at 20°C, a melting point of 17.8°C, a boiling point of 290°C and a refractive index of 1.47.  Viscosity decreases with increasing temperature and water content and can vary from 10-3 to 10 Pas (Segur and Oberstar, 1951).

Applications

A common use of glycerin in experiments has been as an analogue for magmatic intrusions, where glycerin forms liquid-filled cracks in either gelatine (Lister and Kerr, 191; Koyaguchi and Takada, 1994; Takada 1999) or granular material (Bonini et al., 2001; Corti et al., 2001).  These experiments typically look at the propagation of dykes in relation to regional tectonics (e.g. Takada, 1999; Corti et al., 2001).  In one study gypsum powder was added to the glycerin to increase ‘magma’ density (Bonini et al., 2001).

Another application is the study of magma mixing dynamics, either between magmas of different compositions, where glycerin typically represents the more viscous silicic magma (Blake and Camp, 1986; Blake and Ivey, 1986; Campbell and Turner, 1986; Sato and Sato, 2009), or phase mingling between magma and water in submerged lava fountain eruptions (Friedman et al., 2006).

Limitations and tips for use

As a magma analogue it is easy to use experimentally, however, it is a homogenous material, which neglects the solid and gas phases present in natural magmas and their rheological effects on flow dynamics.

Glycerin is non-toxic and presents no hazards to health.  It is easy to clean.

References

Blake S and Campbell IH (1986) The dynamics of magma-mixing during flow in volcanic conduits. Contributions to Mineralogy and Petrology 94: 72-81

Blake S and Ivey GN (1986) Magma-mixing and the dynamics of withdrawal from stratified reservoirs. Journal of Volcanology and Geothermal Research 27: 153-178

Bonini M, Sokoutis D, Mulugeta G, Boccaletti M, Corti G, Innocenti F, Manetti P, and Mazzarini F (2001) Dynamics of magma emplacement in centrifuge models of continental extension with implications for flank volcanism. Tectonics 20(6): 1053–1065

Campbell IH and Turner JS (1986) The influence of viscosity on fountains in magma chambers. Journal of Petrology 27 (1): 1-30

Corti G, Bonini M, Innocenti F, Manetti P, and Mulugeta G (2001) Centrifuge models simulating magma emplacement during oblique rifting. Journal of Geodynamics 31:557–576

Friedman PD, William JM, and Carey S (2006) Experimental simulation of phase mingling in a subaqueous lava fountain. Journal of Geophysical Research 111: B07201

Koyaguchi T and Takada A (1994) An experimental study on the formation of composite intrusions from zoned magma chambers. Journal of Volcanology and Geothermal Research 59: 261-267

Lister JR and Kerr RC (1991) Fluid-mechanical models of crack propagation and their application to magma transport in dykes. Journal of Geophysical Research 96, B6: 10049-10077

McLeod P and Tait S (1999) The growth of dykes from magma chambers. Journal of Volcanology and Geothermal Research 92 (3–4): 231­245

Sato E and Sato H (2009) Study of effect of magma pocket on mixing of two magmas with different viscosities and densities by analogue experiments. Journal of Volcanology and Geothermal Research 181: 115-123

Segur JB and Oberstar HE (1951) Viscosity of Glycerol and its Aqueous Solutions. Industrial and Engineering Chemistry 43 (9): 2117-2120

Takada A (1999) Variations in magma supply and magma partitioning: the role of tectonic settings. Journal of Volcanology and Geothermal Research 93(1–2): 93–110