Introduction

This procedure describes how to setup and execute batch forward modelling using the Geomodeller v1.3 engine on a standard computer (i.e. not a supercomputer). The procedure written here was formulated while running forward modelling on 'billy', a high-performance computer located at the Intrepid Geophysics offices in Brighton, Victoria.

Preparing a model run

Submission via batch file

The forward modelling process is submitted using a batch file. Each batch file contains a series of commands or 'jobs'. An example of a batch file setup to conduct a magnetic forward model is as follows:

(Extract from 'doall_mark.bat') –

@call ManageLithoInversion -batch new_project_from_voxet.job

@call ManageLithoInversion -batch new_magnetic_create_case_from_voxet.job

@call ManageLithoInversion -batch new_magnetic_create_forward_run_from_voxet.job

@call ManageLithoInversion -batch new_magnetic_set_initial_voxet.job

@call ManageLithoInversion -batch new_magnetic_forward_run_from_voxet.job

@call ManageLithoInversion -batch new_magnetic_create_inversion_run_from_voxet.job

@call ManageLithoInversion -batch new_magnetic_inversion_run_from_voxet.job

@call ManageLithoInversion -batch new_magnetic_supersummary.job

@call ManageLithoInversion -batch new_magnetic_evolution.job

@call ManageLithoInversion -batch new_magnetic_section.job

echo ----------------  >> ready.txt

date /T  >> ready.txt

time /T  >> ready.txt

echo Job finished!  >> ready.txt

echo ----------------  >> ready.txt

You will need to add or remove calls to different .job files depending on the nature of the modelling required. A list of example .job files is as follows

Magnetic modelling

Forward modelling

new_magnetic_set_initial_voxet.job

new_magnetic_create_case_from_voxet.job

new_magnetic_create_forward_run_from_voxet.job

new_magnetic_inversion_run_from_voxet.job

new_magnetic_forward_run_from_voxet.job

Geophysical inversion

new_magnetic_create_inversion_from_voxet.job

new_magnetic_inversion_run_from_voxet.job

Geophysical inversion statistical measures

new_magnetic_supersummary.job -

new_magnetic_evolution.job

new_magnetic_section.job

Gravity modelling

Forward modelling

new_gravity_create_case_from_voxet.job

new_gravity_create_forward_run_from_voxet.job

new_gravity_forward_run_from_voxet.job

Geophysical inversion

new_gravity_inversion_run_from_voxet.job

new_gravity_create_inversion_from_voxet.job

new_gravity_inversion_run_from_voxet.job

new_create_gravity_inversion_run_from_voxet.job

Geophysical inversion statistical measures

new_gravity_set_initial_voxet.job

new_gravity_evolution.job

new_gravity_calc_histogram.job

new_gravity_supersummary.job

new_gravity_section.job

Joint geophysical modelling

new_joint_supersummary.job

new_joint_section.job

new_joint_evolution.job

Joint modelling

Joing forward modelling

Joint geophysical inversion

Geophysical inversion statistical measures

new_joint_supersummary.job

new_joint_section.job

new_joint_evolution.job

Editing job files

Setting rock properties

To set the rock properties being used in the inversion, the following files need to be edited:

Magnetic susceptibility

Magnetic_create_case_from_voxet.job

Rock densities (gravity)

Gravity_create_case_from_voxet.job

Joint (joint gravity and magnetic processing)

Joint_create_case_from_voxet.job

Parameters

set wantForwardResponsePerLithology=1 (where 1 sets the flag to execute this statement, and 0 to not execute).

As the name suggests, this produces an .ers file for the foward modelling response from each lithology.

Using 'task' files to submit forward modelling requests.

Task files use Google protobuf language to manage batch requests in Geomodeller v2. The serial nature of executing calls to Geomodeller is much the same as the older '.job' style, but the '.task' file format allows parameters to be specified more easily by terms within the file.

Output files

The type and number of output files will depend on the processes that have been selected (see 'Parameters' section above). Essentially a selection of .ers files are output that show either the calculated or measured response of the potential field being analysed. Each set of files, for example effects_Magnetism will include the total field response and separate files for the X, Y and Z components (effects_MagnetismX, effects_MagnetismY, effects_MagnetismZ).