Public domain satellite gravity inversion offshore Somalia combines layered-Earth and voxel based modelling

Orthographic view voxi mesh pouliquen

Geosoft collaborated with Spectrum Geo and Leeds University on a study that demonstrates how public domain data inversion can reveal a meaningful, basin-scale preliminary density model of the subsurface. This type of approach is a valuable, low-cost aid for mapping the density of the earth in frontier areas, and to facilitate basin exploration. The approach also has scope for application in better-understood basins.

The study was based on a large area offshore East Africa, geologically complex and sparsely surveyed, located between -/+8◦ latitude and encompassing the Western Somalian Basin and part of the Northern Somalian basin. Study objectives were to better understand the crustal architecture over the margin, and to evaluate the added value of a combined inversion scheme.

The combination of 2D and constrained-combined 3D modelling used in the study revealed rifted domains along the Somalian margin defined by distinct basement architectures and density distribution. In the north of the margin over the Obbia basin and in the area beyond in the Northern Somalian basin, the density model indicates more complexity than farther south, and potential extensive areas of hyperextended crust.

The model also confirmed an oceanward progression of oceanic accretion, lying at ~180 km from the coastline in the Juba Lamu basin, 215 km in Coriole and ~350 km in Obbia.

Utilizing largescale regional satellite gravity inversion, made possible by today’s high performance computing, the study revealed how public domain data inversion can provide a realistic density model of the subsurface and help us to understand frontier domains.

Read the full technical paper, published in the September issue of First Break.

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