ctplanet

Create crustal thickness maps of planets from gravity and topography.

Description

ctplanet provides several functions and example scripts for generating crustal thickness maps of a planet from gravity and topography data, and the calculation of hydrostatic relief along density interfaces beneath the lithosphere.

Methods

pyMoho Calculate relief using a constant density crust and mantle.

pyMohoRho Calculate relief using a constant density mantle and a variable density crust.

HydrostaticShapeLith Calculate the relief of hydrostatic interfaces beneath the lithosphere along with the predicted gravity, taking into account rotation and/or tides using the approach of Wieczorek et al. (2019).

HydrostaticShape Calculate the relief of hydrostatic interfaces and predicted gravity of a rotating hydrostatic planet using the approach of Wieczorek et al. (2019).

InertiaTensor_from_shape Calculate the inertia tensor given a radial density profile and shape of each interface.

InertiaTensor_from_C Calculate the inertia tensor given the polar moment of inertia and the gravitational potential coefficients.

moi Calculate the mean, normalized, moment of inertia up to index n.

ReadRefModel Read the reference interior model file.

Example scripts

Moon-Crust A script that demonstrates how to calculate the thickenss of the lunar crust using either a constant or variable density crust. The latter can be used to reproduce the results presented in Wieczorek et al. (2013).

Moon-Core Calculate the hydrostatic relief of the lunar core accounting for the non-hydrostatic potential that comes from the lithosphere.

Mars-Crust A script that demonstrates how to calculate the thickenss of the Martian crust using either a constant or variable density crust. For the variable density crust, the density is assumed to change discontinuously across the dichotomy boundary.

Mars-Crust-hydrostatic-tests Create a crustal thickness map of Mars from gravity and topography and compare how results change if hydrostatic interfaces are not taken into account.

Mars-Crust-InSight Create a crustal thickness map of Mars from gravity and topography, using the InSight crustal thickness constraint.

Mars-Crust-InSight-dichotomy Create a crustal thickness map of Mars from gravity and topography, using the InSight crustal thickness constraint and different densities across the dichotomy boundary.

Mars-fcn Compute the free core nutation period of Mars.

Mars-shape Create images related to Mars in Wieczorek et al. (2019).

Mars-j2 Compute the contribution to the gravitational J2 of Mars from hydrostatic interfaces beneath the lithosphere.

Earth-shape Compute hydrostatic relief of Earth using PREM.

Ceres-shape Calculate the hydrostatic shape of Ceres.

How to install and run ctplanet

Download the ctplanet repository and install using pip

    git clone https://codeberg.org/mark-wieczorek/ctplanet.git
    pip install .

To execute a script

    cd examples
    python Moon-Crust.py

Depending on how your system is set up, it might be necessary to use explicitly python3 and pip3 instead of python and pip in the above commands.

Reference

Wieczorek, M. A., G. A. Neumann, F. Nimmo, W. S. Kiefer, G. J. Taylor, H. J. Melosh, R. J. Phillips, S. C. Solomon, J. C. Andrews-Hanna, S. W. Asmar, A. S. Konopliv, F. G. Lemoine, D. E. Smith, M. M. Watkins, J. G. Williams, M. T. Zuber (2013), The crust of the Moon as seen by GRAIL, Science, 339, 671-675, doi:10.1126/science.1231530.

Wieczorek, M. A., M. Beuthe, A. Rivoldini, and T. Van Hoolst (2019), Hydrostatic interfaces in bodies with nonhydrostatic lithospheres, Journal of Geophysical Research: Planets, 124, doi:10.1029/2018JE005909.