So, I just discovered PREM (the Preliminary reference Earth model) which models the density distribution of matter inside the Earth to any depth.

The PREM is very convenient but since it only depends on the depth I see that is an isotropic model, meaning that it deoesn't matter from which surface coordinates we are digging, it only accounts for radial variations in density from the core. I know that Earth's interior is not distributed in perfect spherical symmetry since there are things like Large low-shear velocity provinces and giant slabs of solid crust floating in the mantle revealed by seismic tomography, and gravitational anomalies.

I was wondering if there is a much more accurate model for the density distribution of Earth that accounts for the aforementioned asymmetries, and where can I download that data?


1 Answer 1


Here's an extensive list of Earth models, many of which are anisotropic. You'll probably want to focus on tomographic models rather than reference models.


  • $\begingroup$ That's a nice resource but does any of these models include mass density distributions? I only see seismic velocity measurements and I want the mass distribution. $\endgroup$
    – Swike
    May 8, 2021 at 11:00
  • $\begingroup$ Unfortunately, many seismic models don't explicitly provide density. PREM is very convenient in that it gives you a bunch of quantities. Of course, density can easily be calculated from seismic velocities if you have estimates for shear and/or bulk moduli. $\endgroup$
    – g.z.
    May 8, 2021 at 21:12
  • $\begingroup$ How should I proced then? Should I wait a few weeks for someone to show a density model or is it probably not found anywhere? Should I calculate it? How? $\endgroup$
    – Swike
    May 12, 2021 at 15:04
  • $\begingroup$ Waiting probably won't be helpful. I don't know what you're trying to do, so it's kind of hard to give advice on how you should proceed. Why isn't the PREM density profile suitable for what you're trying to do? $\endgroup$
    – g.z.
    May 12, 2021 at 21:10
  • $\begingroup$ I want to calculate free-fall paths through Earth's interior. I first did it with PREM but I now want to make a second order approximation, one that implies the non-symetric distribution of matter in Earth's interior to see what trajectories are possible and other curiosities (like what is the antipodal shortest travel time in the true Earth). That's why I need a more realistic model than PREM, because my goal is to adress a physics example with varying degrees of accuracy to show how complexity makes for devils in the details. $\endgroup$
    – Swike
    May 15, 2021 at 21:33

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