Hi folks,
I have recently been working on a paper on thermo-chemical evolution of Mars: The early geodynamic evolution of Mars-type planets, Siqi Zhang 2016. The paper is quite clear and gives all parameters except initial perturbations. In their main text, they just mentioned that perturbations are added to initial temperature field and the thickness of lithosphere, but they did not specify the numbers. Additionally, the initial temperature profile within lithosphere in figure 4 (reference case) looks like half-space cooling profile, but they did not mention that. I tried half-space cooling, but the difference is obvious, esp. when comparing surface heat flux in figure 3b.
I had a couple of tests using my plugins with some arbitrarily selected values for initial temperature perturbation amplitude, initial lithosphere thickness perturbation amplitude and wave number. The initial temperature perturbation wave number can be seen in their figure 2A1 reference case where you can see 6 cold + 6 hot sectors near the surface. So I guess the perturbation may look like A_T*\sin(6 \phi) where \phi is longitude and A_T is amplitude. Tests with A_T = 100 K, A_{litho} = 15 km (lithosphere thickness perturbation amplitude), and mean thickness of lithosphere = 70 km, show the hot plumes destroy lithosphere (see figure below).This could be due to large temperature perturbation amplitude or thin lithosphere, etc. But there could be a large free parameter space to explore, I don’t think having lots of tests is a wise move.
I have access to the source code of the paper, but it’s been updated a few times for their later projects, and there is no input file either. I made contact with the authors, the corresponding author is off the radar recently due to personal issue, while the other author, Craig O’Neill, responded with no clarification on these numbers. So I’m wondering if there is a way to read figures 2-4 carefully and get a better guess of the perturbations. Any ideas would be appreciated!
Best,
Mingming
The early geodynamic evolution of Mars-type planets,Zhang2016.pdf (6.7 MB)