PLANETARY MUSINGS

Classic paper on gravity and lithospheric stress

Sleep, NH and RJ Phillips, Gravity and lithospheric stress on the terrestrial planets with reference to the Tharsis region of Mars, JGR, 90, 4469-4489, (1985), ADSABS Entry.

I recently re-read most of this classic paper. Trying to put together knowledge on gravity, topography, and tectonics in order to understand the state and evolution of planetary lithospheres is a long-standing problem. For small planets like Mars, membrane stresses (often known as fiber stresses to engineers thinking about pressure vessels) are important (not the case on Earth); these and a few other authors like Turcotte, Banerdt and their co-workers laid out these problems for Mars. Tharsis is most likely largely isostatically compensated, and this is an important first step to understanding circum-Tharsis tectonics. The treatment is relatively complete for its purpose, but we have a bit more data today and we worry about more than just isostatically compensated loading of the planet. However, the discussion of calculating gravitational potentials is lucid and useful and membrane stresses instructive.