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Experiment 2 (9999 runs)

Differences from simulations of Experiment 1

• These simulations are run using a more recent version of StagYY.

• They use a better viscosity activation volume so are more realistic.

• They use a different routine to calculate density from the Perple_X files. The previous simulations have a bug that means that the depth-pressure conversion is not correct and therefore the density is incorrect in the simulations.

• Melt can be extruded or erupted at the surface.

• Viscosity has a change at around 660, depending on the Ringwoodite phase transition calculated by perplex.

• Outputs are stored in hdf5 format.

• The coordinates of the grids are saved in Node files.

Similarities between simulations

• Simulations are run in 2D with StagYY (Tackley 2008, Hernlund & Tackley 2008).

• There are 9999 simulations.

• These are saved as: ParXXX_bdry.tgz, where XXX denotes run number.

• Each simulation uses the same Fortran code "stagyy".

• 'defaults_include.f90' (link) contains all the important default convection parameters, which need to be included in papers etc., but which do not vary between simulations.

• Some of the parameters in defaults_include.f90 are over-written by parameters in the parameter file called 'par'.

• Some simulation tar files contain multiple par files. The one called "par" is the only one used in the simulation.

Differences between simulations

• The parameters that vary between simulations are set in the 'par' file. These are mostly (but maybe not all) labelled '**varies**'

• These parameters are set from the table contained in: VaryingParameters24Oct17.dat (link).

• Each line lists the varying parameters for one simulation. E.g. line 10 contains all the parameters for simulation 10, saved in Par10_bdry.tgz.

• These parameters are listed below, under Varying parameters.

• Each simulation also uses 3 perplex files HARZXXX_1.tab, MORBXXX_1.tab and PRIMXXX_1.tab that contain the mineral physics data for the three end-member rock types, harzburgite, basalt and primordial. More details are included below under Perple_X

Varying parameters

VaryingParameters24Oct17.dat contains 9999 lines (number of runs). Below are the definitions of the varying parameters written as (column, StagYY parameter name, description, units):

18 of these are set in the 'par' file:

1. Rh: Initial radiogenic heating [W/kg]

2. core_Kppm: Initial core radiogenic potassium concentration [ppm]

3. Dpartition_hpe: Partition coefficient for radioactive tracers upon melting [factor]

4. dHeat_dprim: Radioactive heating enhancement in primordial material with respect to bulk mantle [factor]

5. T0_init: Initial mantle potential temperature [K]

6. botT_val: Initial CMB temperature [K]

7. stressY_eta Surface yield stress [M Pa]

8. NOT USED

9. eta0: Reference viscosity [Pa s]

10. V_eta_UM: Viscosity activation volume upper mantle [m^3]

11. V_eta_LM: Viscosity activation volume lower mantle [m^3]

12. E_eta_UM: Viscosity activation energy upper mantle

13. E_eta_LM: Viscosity activation energy lower mantle

14. d_eta_660: Viscosity jump at 660 factor

15. deta_primordial: Viscosity contrast between primordial and bulk mantle [factor]

16. d_primordial: Thickness of primordial material [km] (if = 0, there will still be a PRIMXXX_1.tab file, it is just not used)

17. basalt_frac_ref: Fraction of basalt end-member in mantle [factor]

18. intrude_fraction: Fraction of of melt intruded into crust vs erupted at surface

The following 17 parameters affect Perple_X calculations, but are not set in the 'par' file:

19. MORB Al2O3 mol% for Perple_X calculations

20. MORB CaO

21. MORB FeO

22. MORB MgO

23. MORB Na2O

24. MORB SiO2

25. HARZ Al2O3

26. HARZ CaO

27. HARZ FeO

28. HARZ MgO

29. HARZ SiO2

30. PRIM Al2O3

31. PRIM CaO

32. PRIM FeO

33. PRIM MgO

34. PRIM Na2O

35. PRIM SiO2

Any extra columns are not used.

Perple_X mineral physics information

For details about the Perple_X free energy minimisation package see Connolly (2009). Version Perple_X_6.6.8_OSX_Intel_generic_MC_Feb_24_2013 was used. For a given set of parameters (13-30) this produces ascii look up tables *XXX_1.tab. Not all have identical grids. Each file contains a header. The format of these files and headers is:

• Version

• Table name

• Lowest temperature (K)

• Temperature grid spacing

• Number of temperature grid points

• Lowest pressure (bar)

• Pressure grid spacing

• Number of pressure grid points

• Number of columns

• The columns are: temperature, pressure, density, bulk modulus, shear modulus, enthalpy, and thermal expansivity.

Outputs from the StagYY simulations

• They are stored in the +hdf5 directory in each tar file.

• Each write step is stored as entry in the h5 file.

• The time between frames may vary significantly.

• Files are numbered sequentially by frame, starting at 0 (the initial condition).

• Number does not refer to age. The last number refers to calculation node on the cluster.

• All these results only use a single node.

• Format is Observation_ObservationWriteStep_node.h5.

Output fields

• Observations

• NodeCoordinates coordinates of grid

• Age time since each tracer last melted

• Basalt basalt fraction in each cell

• Composition 1=harz, 0=bs

• Dynamic_Pressure

• Harzburgite

• MeltFrac melt fraction in each cell

• Pressure

• Primordial primordial component in each cell

• StrainRate

• Stress

• SurfaceDynamicTopography

• Temperature