Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-19T01:23:26.837Z Has data issue: false hasContentIssue false
  • English
  • Français

Radial spreading of viscous-gravity currents with solidifying crust

Published online by Cambridge University Press:  26 April 2006

Jonathan H. Fink  and
Ross W. Griffiths
Jonathan H. Fink
Affiliation:
Research School of Earth Sciences, Australian National University, Canberra, Australia Geology Department, Arizona State University, Tempe, AZ 85287, USA
Ross W. Griffiths
Affiliation:
Research School of Earth Sciences, Australian National University, Canberra, Australia
Get access Rights & Permissions [Opens in a new window]

Abstract

We have investigated the effect of a solidifying crust on the dynamics and surface morphology of radial viscous-gravity currents. Liquid polyethylene glycol was admitted into the base of a tank filled with cold sucrose solution maintained at a temperature below the wax freezing point. As the radial current advanced away from the inlet, its surface solidified and deformed through a combination of folding and fracturing. For the warmest experiments, during which solidification did not occur, the radius of the current increased in proportion to the square root of time, as demonstrated both experimentally and theoretically for isothermal viscous fluids by Huppert (1982). When cooling was sufficiently rapid, solid crust formed and caused the spreading rate to decrease. A cooling model combining conduction in the wax with convection in the sucrose solution predicts the distance from the source at which the solid crust first appeared

Progressively colder experiments revealed a sequence of surface morphologies which resembled features observed on cooling lava flows and lava lakes. Flows in which crust formed very slowly developed marginal levees which contained and channelled the main portion of the current. Colder flows with more rapid crust growth formed regularly spaced surface folds, multi-armed rift structures complete with shear offsets, and bulbous lobate forms similar to pillow lavas seen under the ocean. The same transitions between modes of surface deformation were also generated by keeping the ambient water temperature constant and decreasing the extrusion rate. This demonstration that surfaces can exhibit a well-defined sequence of morphologies which depend on the underlying flow conditions offers the prospect of more successful interpretation of natural lava flows.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 221 , December 1990 , pp. 485 - 509
Copyright
© 1990 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anderson, S. W. & Fink, J. H., 1990 The development and distribution of lava surface textures at the Mount St. Helens dacite dome. In Lava Flows and Domes: Emplacement Mechanisms and Hazard Implications (ed. J. H. Fink). IAVCEI Proc. in Volcanology, vol. 2, pp. 25–46.
Baloga, S. M.: 1987 Lava flows as kinematic waves. J. Geophys. Res. 92, 9271–9279.Google Scholar
Baum, B. A., Krantz, W. B., Fink, J. H. & Dickinson, R. E., 1989 Taylor instability in rhyolite lava flows. J. Geophys. Res. 94, 5815–5828.Google Scholar
Biot, M. A.: 1961 Theory of folding of stratified viscoelastic media and its implications in tectonics and orogenesis. Bull. Geol. Soc. Am. 72, 1595–1620.Google Scholar
Blake, S.: 1990 Viscoplastic models of lava domes. In Lova Flows and Domes: Emplacement Mechanisms and Hazard Implications (ed. J. H. Fink). IAVCEI Proc. in Volcanology, vol. 2, pp. 88–128.
Carslaw, H. S. & Jaeger, J. C., 1959 Conduction of Heat in Solids. Oxford University Press.
Crisp, J. A. & Baloga, S. M., 1990 A model for lava flows with two thermal components. J. Geophys. Res. 95, 1255–1270.Google Scholar
Didden, N. & Maxworthy, T., 1982 The viscous spreading of plane and axisymmetric gravity currents. J. Fluid Mech. 121, 27–42.Google Scholar
Fink, J. H.: 1980a Surface folding and viscosity of rhyolite flows. Geology 8, 250–254.Google Scholar
Fink, J. H.: 1980b Gravity instability in the Holocene Big and Little Glass Mountain rhyolitic obsidian flows, northern California. Tectonophys. 66, 147–166.Google Scholar
Fink, J. H.: 1983 Structure and emplacement of a rhyolitic obsidian flow: Little Glass Mountain, Medicine Lake Highland, northern California. Bull. Geol. Soc. Am. 94, 362–380.Google Scholar
Fink, J. H. & Fletcher, R. C., 1978 Ropy pahoehoe: Surface folding of a viscous fluid. J. Volcanol. Geotherm. Res. 4, 151–170.Google Scholar
Fink, J. H. & Zimbelman, J. R., 1986 Rheology of the 1983 Royal Gardens basalt flows, Kilauea Volcano, Hawaii. Bull. Volcanol. 48, 87–96.Google Scholar
Greeley, R. & Womer, M. B., 1981 Mare basin filling on the moon: Laboratory simulations. In Proc. Lunar Planet. Sci. Conf. vol. XII, pp. 651–663.Google Scholar
Hallworth, M. A., Huppert, H. E. & Sparks, R. S. J. 1987 A laboratory simulation of basaltic lava flows. Mod. Geol. 11, 93–107.Google Scholar
Hodgson, G. W.: 1969 An experimental investigation of simulated lava flows using carbowax materials. M. S. thesis, Wright-Patterson A. F. B., Ohio, Air Force Inst. of Technology.
Hoult, D. P.: 1972 Oil spreading on the sea. Ann. Rev. Fluid Mech. 4, 341–368.Google Scholar
Hulme, G.: 1974 The interpretation of lava flow morphology. Geophys. J. R. Astron. Soc. 39, 361–383.Google Scholar
Huppert, H. E.: 1982 The propagation of two-dimensional and axisymmetric viscous gravity currents over a rigid horizontal surface. J. Fluid Mech. 121, 43–58.Google Scholar
Huppert, H. E., Shepherd, J. B., Sigurdsson, H. & Sparks, R. S. J. 1982 On lava dome growth, with application to the 1979 lava extrusion of the Soufriere of St. Vincent. J. Volcanol. Geotherm. Res. 14, 199–222.Google Scholar
Huppert, H. E. & Sparks, R. S. J. 1988 Melting the roof of a chamber containing a hot, turbulently converting fluid. J. Fluid Mech. 188, 107–131.Google Scholar
Malin, M. C.: 1980 Lengths of Hawaiian lava flows. Geology 8, 306–308.Google Scholar
Moore, J. G. & Lockwood, J. P., 1978 Spreading cracks on pillow lava. J. Geol. 86, 661–671.Google Scholar
Park, S. O.: 1981 Simulation of lava flow with small scale models. Ph.D. thesis. Ames Iowa, Iowa State University, 173 pp.
Pieri, D. C. & Baloga, S. M., 1986 Eruption rate, area and length relationships for some Hawaiian lava flows. J. Volcanol. Geotherm. Res. 30, 29–45.Google Scholar
Pinkerton, H.: 1987 Factors affecting the morphology of lava flows. Endeavour 11, 73–79.Google Scholar
Pinkerton, H. & Sparks, R. S. J. 1978 Field measurements of the rheology of lava. Nature 276, 383–386.Google Scholar
Tepley, L. & Moore, J. G., 1974 Fire under the sea: The origin of pillow lava. 16 mm sound motion picture, Moonlight productions, Mountain View, Calif.Google Scholar
Turcotte, D. L. & Schubert, G., 1982 Geodynamics. John Wiley.
Turner, J. S.: 1973 Buoyancy Effects in Fluids. Cambridge University Press.
Wadge, G.: 1978 Effusion rate and the shape of aa lava flow-fields on Mount Etna. Geology 6, 503–506.Google Scholar
Walker, G. P. L.: 1973 Lengths of lava flows. Phil. Trans. R. Soc. Lond. A 274, 107–118.Google Scholar