*Greg Houseman* *Institute
of Geophysics and Tectonics* *School of
Earth and Environment* *University of
Leeds* *Leeds, LS2 9JT* *UK*

tel: (+44) 113 343 5206; fax: (+44) 113 343 5259; e-mail: greg@earth.leeds.ac.uk

Return to the University of Leeds **Earth
Sciences Home Page** or the **Geophysics
Group **home page.

Numerical simulation of lithospheric deformation and mantle convection

Development of efficient numerical methods for continuum mechanics problems

Interaction of lithosphere and mantle in tectonically active regions

Investigation of lithospheric and crustal structure using seismic tomography

**Current and Recent Projects**:

1) The Carpathian Basins Project (CBP) comprising a major seismological investigation of the structure of the lithosphere and crust beneath the Pannonian and Vienna Basins of Central Europe, together with computational modelling using 3D finite element methods on parallel super-computers. Supported by NERC.

2) The *oregano* project: development of a suite
of software for modelling 3D continuum deformation in a non-linear
viscous medium using parallel processor technology. *Oregano*
was originally developed with Lykke Gemmer and Stuart Borthwick at
Leeds, and continues with Piroska Lorinczi's work on viscous flow
models of lithospheric deformation.

3) Development of a 3D viscoelastic deformation program in collaboration with Prof Peter Jimack of the School of Computing and Dr Elek Postek. Supported by EPSRC, we aim in this project to develop a capacity to accurately compute the ground displacement history around major earthquake events and, combined with observations, to determine how faulting evolves on major fault systems like that which caused the disastrous earthquake of Kashmir in late 2005.

4) Teleseismic tomography of the Paleozoic foldbelts of South-east Australia: we analyse arrival times of signals produced by earthquakes on the edges of the Australian plate in order to map the variation of seismic wavespeed within the Australian lithosphere.

5) Rayleigh-Taylor instability in a non-Newtonian fluid representing the Earth's lithosphere: if lithosphere is locally thickened by tectonic convergence, it is likely to be unstable with respect to convective overturn with the mantle below. We've shown that the process is described by a simple power-law growth that allows us to predict the growth time of the instability.

6) Deformation of subducted oceanic lithosphere: when oceanic lithosphere is subducted it descends through the upper mantle and meets resistance at a depth of 670 km. The deformation of thje slab is controlled by a balance between buoyancy forces and lithospheric strength. Comparing the observed mode of deformation with these models allows us to estimate the effective strength of the slab.

7) Lithospheric anisotropy in a region of continental deformation. A comparison of observed lithospheric anisotropy directions with the directions computed for a thin viscous sheet model of the deforming lithosphere, support the view that lithospheric deformation is distributed broadly through the region affected by the collision and is best described using a non-Newtonian power law rheology.

8)
Time-dependence and geometry of thermal structures in chaotic
thermal convection: the mantle convects vigorously because of
heat generated by radioactive decay of unstable elements. The
planform and time dependence of the convection depend on heating mode
and viscosity variation. This image shows a simulation of
convective flow using the 3D program TDCON, developed by the author.

8) Development of the basil/sybil finite deformation programs: these programs, developed in conjunction with T. Barr and L. Evans permit the calculation of deformation fields in a 2D non-linear viscous medium, with a wide-range of geometries and boundary conditions. Recent developments include thin viscous sheet on a sphere, and cylindrically axisymmatric solutions.

9) The
core-mantle boundary interface: PhD project with Bryony
Youngs: D" is an anomalous layer at the base of the mantle -
involving intrinsically dense material and phase changes. In
this project we have developed new techniques for calculating how a
dense layer at the base of the mantle is influenced by convection in
the overlying mantle, with the object of explaining seismic
observations of complex irregular structures at the base of the
mantle.

The degree-three Spherical Harmonic oscillations of the Earth - one family of reverberations which occur when the Earth is hit by a large earthquake

The movement of Gondwanaland relative to the earth's magnetic pole during the Paleozoic - pieced together from paleomagnetic measurements

The Mesozoic-Tertiary break up of Gondwanaland - also derived from paleomagnetic data.

**Professional Activities:**

**AGU **AGU
Fellow: 2001

AGU Budget and Finance Committee: 2002-2004

**Tectonophysics Section, AGU**

President-elect: 2002-2004

President: 2004 - 2006

**IASPEI - International
Association of Seismology and Physics of the Earth's Interior**

2nd Vice-President: 2003-

**Previous Appointments:**

Monash University: 1988 - 2000

Australian National University: 1984-1987

Harvard University : 1982-1984

Schlumberger Seaco: 1978

**Education:**

Cambridge University: 1978-1981 (PhD)

University of Sydney: 1974-1977 (BSc Hons I, University
Medal)

St Dominics College, Penrith, NSW

Graeber, F.M., G.A. Houseman, and S.A. Greenhalgh, Teleseismic tomography of the Western Lachlan Orogen and the Newer Volcanic Province, Southeast Australia,Geophys. J. Int., 149, 249-266, 2002.

Rawlinson, N., G.A. Houseman, C.D.N. Collins, and B.J. Drummond, New evidence of Tasmania's tectonic history from a novel seismic experiment,Geophys. Res. Lett., 28, 3337-3340, 2001.

Houseman, G.A., and P. Molnar, Mechanisms of lithospheric rejuvenation associated with continental orogeny, inContinental Reactivation and Reworking, Eds. Miller, J.A., Holdsworth, R.E., Buick, I.S., and Hand, M.,Geol. Soc. Lond. Spec. Publ., 184, 13-38, 2001.

Roberts, E.A., and G.A. Houseman, Geodynamics of Central Australia during the intraplate Alice Springs Orogeny: thin viscous sheet models, inContinental Reactivation and Reworking, Eds. Miller, J.A., Holdsworth, R.E., Buick, I.S., and Hand, M.,Geol. Soc. Lond. Spec. Publ., 184, 139-164, 2001.

Rawlinson, N., and G.A. Houseman, Inversion of seismic refraction and wide-angle reflection traveltimes for 3-D layered crustal structure,Geophys. J. Int., 145, 381-400, 2001.

Houseman, G.A., The strength of a continent,Science, 287, 814-815, 2000.

Houseman, G., E. A. Neil, and M.D. Kohler, Lithospheric instability beneath the Transverse Ranges of California,J. Geophys. Res.,105, 16237-16250, 2000.

Neil, E.A., and G.A. Houseman, Rayleigh-Taylor instability of the upper mantle and its role in intraplate orogeny,Geophys. J. Int., 138, 89-107, 1999.

Molnar, P., G. Houseman and C. Conrad, Rayleigh-Taylor instability and convective thinning of mechanically thickened lithosphere: effects of non-linear viscosity decreasing exponentially with depth and of horizontal shortening of the layer,Geophys. J. Int., 133,568-584, 1998.

Rawlinson, N., and G.A. Houseman, Inversion for interface structure using teleseismic traveltime residuals,Geophys. J. Int., 133,756-772, 1998.

Davis, P., P. England, and G. Houseman, Comparison of shear wave splitting and finite strain from the India-Asia collision zone,J. Geophys. Res., 102, 27511-27522, 1997.

Houseman, G.A., and D. Gubbins, Deformation of subducted oceanic lithosphere,Geophys. J. Int., 131, 535-551, 1997.

Neil, E.A., and G.A. Houseman, Geodynamics of the Tarim Basin and the Tian Shan,Tectonics, 16, 571-584, 1997.

Houseman, G., and Molnar, P., Gravitational (Rayleigh-Taylor) instability of a layer with non-linear viscosity and convective thinning of continental lithosphere,Geophys. J. Int., 128, 125-150, 1997.

Wang, Y., and Houseman, G., Point source tau-p transform: a review and comparison of computational methods,Geophysics, 62, 325-334, 1997.

Schmalzl, J., Houseman, G.A., and Hansen, U., Mixing in vigorous time-dependent 3D convection and application to the Earth's mantle,J. Geophys. Res., 101, 21847-21858, 1996.

Houseman, G., and England, P.C., A lithospheric thickening model for the Indo-Asian collision, inTectonic Evolution of Asia, A.Yin & T.M. Harrison (Eds.), Cambridge University Press, New York, pp3-17, 1996

Barr, T.D., and Houseman, G., Deformation fields around a fault embedded in a non-linear ductile medium,Geophys. J. Int., 125, 473-490, 1996.

Wang, Y., and Houseman, G., Tomographic inversion of reflection seismic amplitude data for velocity variation,Geophys. J. Int., 123, 355-372, 1995.

Busse, H., U. Christensen, R. Clever, L. Cserepes, C. Gable, E. Giannandrea, L. Guillou, G. Houseman, H.-C. Nataf, M. Ogawa, M. Parmentier, C. Sotin and B. Travis, 3D convection at infinite Prandtl number in Cartesian geometry - a benchmark comparison,Geophys. Astrophys. Fluid Dyn., 75, 39-59, 1994.

Houseman, G. and England, P., Crustal Thickening versus lateral expulsion in the Indian-Asian continental collision,J. Geophys. Res., 98, 12233-12249, 1993.

Houseman, G. The thermal structure of mantle plumes: axisymmetric or triple-junction?Geophys. J. Int., 102, 15-24, 1990.

Houseman, G., The dependence of convection planform on mode of heating,Nature, 332, 346-349, 1988.

England, P. and Houseman, G., Finite strain calculations of continental deformation II: comparison with the India-Asia collision zone,J. Geophys, Res. 91, 3664-3676, 1986.

Houseman, G. and England, P., Finite strain calculations of continental deformation I: methods and general results for convergent zones,J. Geophys. Res., 91, 3651-3663, 1986.

Houseman, G. and England, P., A dynamical model of lithosphere extension and sedimentary basin formation,J. Geophys. Res., 91, 719-729, 1986.

England, P., Houseman, G. and Sonder, L., Length scales for continental deformation in convergent, divergent and strike-slip environments: Analytical and approximate solutions for a thin viscous sheet model,J. Geophys. Res., 90, 3551-3557, 1985.

England, P. and Houseman, G., Role of lithospheric strength heterogeneities in the Tectonics of Tibet and neighbouring regions,Nature, 315, 297-301, 1985.

Houseman, G. and McKenzie, D.P., The onset of convective instability in the Earth's mantle,Geophys. J.R. astr. Soc., 68, 133-164, 1982.

Houseman, G., McKenzie, D.P. and Molnar, P., Convective instability of a thickened boundary layer and its relevance for the thermal evolution of continental convergent belts,J. Geophys. Res., 86, 6115-6132, 1981.