Towards Spherical Mesh Gravity and Magnetic Modelling in an HPC Environment
Abstract
Staff at Geoscience Australia (GA), Australia's Commonwealth Government geoscientific agency, have routinely performed 3D gravity and magnetic modelling as part of geoscience investigations. For this work, we have used software programs that have been based on a Cartesian mesh spatial framework. These programs have come as executable files that were compiled to operate in a Windows environment on single core personal computers (PCs). To cope with models with higher resolution and larger extents, we developed an approach whereby a large problem could be broken down into a number of overlapping smaller models (';tiles') that could be modelled separately, with the results combined back into a single output model. To speed up the processing, we established a Condor distributed network from existing desktop PCs. A number of factors have caused us to consider a new approach to this modelling work. The drivers for change include; 1) models with very large lateral extents where the effects of Earth curvature are a consideration, 2) a desire to ensure that the modelling of separate regions is carried out in a consistent and managed fashion, 3) migration of scientific computing to off-site High Performance Computing (HPC) facilities, and 4) development of virtual globe environments for integration and visualization of 3D spatial objects. Some of the more surprising realizations to emerge have been that; 1) there aren't any readily available commercial software packages for modelling gravity and magnetic data in a spherical mesh spatial framework, 2) there are many different types of HPC environments, 3) no two HPC environments are the same, and 4) the most common virtual globe environment (i.e., Google Earth) doesn't allow spatial objects to be displayed below the topographic/bathymetric surface. Our response has been to do the following; 1) form a collaborative partnership with researchers at the Colorado School of Mines (CSM) and the China University of Geosciences (CUG) to develop software for spherical mesh modelling of gravity and magnetic data, 2) to ensure that we had access to the source code for any modelling software so that we could customize and compile it for the HPC environment of our choosing, 3) to learn about the different types of HPC environments, 4) to investigate which type of HPC environment would have the optimum mix of availability to us, compute resources, and architecture, and 5) to promote the in-house development a virtual globe application that is built on an open-source Eclipse Rich Client Platform (RCP) called ';EarthSci' that in turn makes use of the NASA World Wind Software Development Kit (SDK) as the globe rendering engine. We hope to have an initial test capability in place in the early part of 2014. With a region-of-interest enclosing 40-180 degrees E, 0-90 degrees S, the first application will be very coarse compared to our final aspirations. This work will be based on the following; a) the global CRUST1.0 litho-model, b) the GOCO03S spherical harmonic satellite gravity model, and c) the EMAG2 global grid of the anomaly of the magnetic intensity. These development activities will enable us to understand the geology of the Australian region and to use this knowledge in a range of applications, including mineral and energy exploration, natural hazard mitigation, and groundwater management.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFMGP51C1097L
- Keywords:
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- 0903 EXPLORATION GEOPHYSICS Computational methods: potential fields;
- 1219 GEODESY AND GRAVITY Gravity anomalies and Earth structure;
- 1517 GEOMAGNETISM AND PALEOMAGNETISM Magnetic anomalies: modeling and interpretation;
- 1932 INFORMATICS High-performance computing