Lithosphere Thickness Variations

The Conrad and Lithgow-Bertelloni [2006] model for lithosphere thickness characterizes lateral variations in lithosphere thickness across the surface of the earth (see above figure). Oceanic lithosphere is assigned a thickness proportional to the square root of its age (ages are taken from Muller et al., [1997]). For continental areas, characteristic thickness is determined following the method of Gung et al. [2003], who employ the maximum depth for which the seismic velocity anomaly (as determined using Ritsema et al.'s [2004] seismic tomography model S20RTSb) is consistently greater than +2%. Here we imposed 100 km as the minimum continental and maximum oceanic characteristic thickness. Remember that material properties such as viscosity vary continuously throughout the depth of the lithosphere, so the definition of “thickness” may vary. The Conrad and Lithgow-Bertelloni [2006] model does not assume any particular definition, but instead characterizes lateral variations in layer thickness (see Conrad and Lithogow-Bertelloni [2006]).

Model: The Conrad and Lithgow-Bertelloni [2006] model for lithosphere thickness can be downloaded here.

Format: Longitude (deg), Latitude (deg), Thickness (km)

Citation: Please cite the following paper when using this model:

Conrad, C.P., and C. Lithgow-Bertelloni (2006), Influence of continental roots and asthenosphere on plate-mantle coupling, Geophysical Research Letters, 33, L05312, doi:10.1029/2005GL025621. [online version] [reprint]

References listed above:

Gung, Y., M. Panning, and B. Romanowicz, Global anisotropy and the  of continents, Nature, 422, 707-711, 2003.

Muller, R.D., W.R. Roest, J.-Y. Royer, L.M. Gahagan, and J.G. Sclater, Digital isochrons of the world’s ocean floor, J. Geophys. Res., 102, 3211-3214, 1997.

Ritsema, J., H.J. van Heijst, and J.H. Woodhouse, Global transition zone tomography, J. Geophys. Res., 109, B02302, doi:10.1029/2003JB002610, 2004.