Author:Durrheim, RJ; Vogt, D; Manzi, MDate:Aug 2013Gold is currently mined at depths reaching 4km in the Witwatersrand basin of South Africa. Geophysical techniques have been used to explore for new resources, and to design and operate mines efficiently and safely. The authors report on ...Read more
Author:Durrheim, RJ; Dirks, PHGM; Nyblade, AA; Graham, G; Webb, SJ; Jones, MQWDate:Sep 2009AfricaArray (www.africaarray.org) is a long-term programme to build geosciences capacity in Africa in support of the mineral, petroleum, groundwater and environmental sectors. It seeks to do this by establishing effective Africa-based education ...Read more
Author:Van Schoor, Michael; Fourie, CJSDate:Oct 2014Coal remains South Africa’s most abundant and cheapest source of energy, and there is an ever-increasing necessity for optimal and safe extraction of the remaining reserves. Increasing focus on cost-effective mining and zero harm to the ...Read more
Author:Botai, OJ; Combrinck, WL; Sivakumar, VDate:Sep 2009Recovering geodetic parameters such as tropospheric delay and geodetic site positions and monitoring their variations in time has important applications for studying the processes of the dynamic earth. Geodetic position time series exhibit ...Read more
Author:Malan, DF; Napier, JALDate:15 Aug 1995Microscopic observations indicate that intra- and transgranular fracturing are ubiquitous processes in the damage of rock fabrics. Extensive modelling of intergranular fracturing has been carried out previously using the distinct-element ...Read more
Author:Vogel, JC; Talma, AS; Heaton, THE; Kronfeld, JDate:Jul 1999The solubility of uranium in groundwater is very sensitive to changes in redox conditions. Many secondary sandstone-type uranium deposits have been formed when soluble U has precipitated after encountering reducing conditions in the subsurface. ...Read more
Author:Van Schoor, MichaelDate:Jan 2015This chapter includes a collection of additional case study examples relating to some of the most pertinent coal problems described in this book. Where possible, local coal examples were selected for inclusion, but otherwise the selected ...Read more
Author:Van Schoor, Michael; du Pisani, P; Vogt, DDate:28 Feb 2006The two major precious metal ore deposits of South Africa, the Bushveld Complex (platinum) and the Witwatersrand Basin (gold), exhibit remarkable lateral continuity on a regional scale. Consequently, the geometry of the respective planar ...Read more
Author:Van Schoor, Michael; Binley, ADate:Dec 2009The applicability of tunnel-to-tunnel electrical resistance tomography (ERT) for imaging disruptive geological structures ahead of mining, in an igneous platinum mining environment is assessed. The geophysical targets of interest are slump ...Read more
Author:Fourie, S; Van Schoor, Michael; Vogt, D; van der Walt, J; Jikelo, A; Campbell, G; Du Plessis, ADate:Jan 2015This chapter introduces a range of geophysical methods that may be applicable to coal mining and exploration problems. The focus of these discussions is on emphasising the link between geology and physics – and how the different geophysical ...Read more
Author:Fourie, CJS; Du Plessis, SJ; Henry, GDate:Nov 2008The Waterberg Coalfield in the Limpopo Province of South Africa contains vast resources of coal that will ensure the country's energy security well into the future. The coalfield is situated in the Karoo-age Ellisras Basin and at present hosts ...Read more
Author:Pivan, X; Krug, Marjolaine J; Herbette, SDate:Sep 2016This study reinvestigates the work of Lutjeharms et al. (2001, 2003) who documented the properties of a Natal Pulse using isopycnal Lagrangian floats. We combined Lagrangian analyses and Eulerian maps derived from objective analysis to better ...Read more
Author:Braby, L; Backeberg, Björn C; Ansorge, I; Roberts, MJ; Krug, Marjolaine J; Reason, CJCDate:Aug 2016Analyzing eddy characteristics from a global data set of automatically tracked eddies for the Agulhas Current in combination with surface drifters as well as geostrophic currents from satellite altimeters, it is shown that eddies from the ...Read morecb
Author:Van Schoor, Michael; Mare, LDate:Jan 2015This chapter explains why geophysicists usually want to know as much as possible
about the physical properties of the different lithological units in an area before
embarking on a geophysical survey. We also highlight some of the common ...Read more
Author:Robertson, I; Loader, NJ; Froyd, CA; Zambatis, N; Whyte, I; Woodborne, SDate:Oct 2006The large girth and immense size of the baobab has caused many to speculate about its age. Unfortunately reliable age estimates cannot be determined from growth rates as the girth varies in response to different moisture regimes. In a similar ...Read more
Author:Sutcliffe, PRDate:Aug 1995Geomagnetic field research carried out at the Hermanus Magnetic Observatory over the past decade is reviewed. An important aspect of this research has been the study of geomagnetic field variations, with particular emphasis on ULF geomagnetic ...Read more
Author:Mavonga, T; Durrheim, RJDate:Sep 2009A probabilistic approach was used to assess the seismic hazard in Democratic Republic of Congo and surrounding areas. Seismic hazard maps were prepared using a 90-year catalogue compiled for homogeneous Ms magnitudes; the attenuation relations ...Read more
Author:Oettli, P; Tozuka, T; Izumo, T; Engelbrecht, FA; Yamagata, TDate:Nov 2013The Madden–Julian Oscillation (MJO) is the major mode of intraseasonal variability (30–60 days) in the tropics, having large rainfall impacts globally, and possibly on southern Africa. However, the latter impact is not well understood and ...Read more
Author:Kassa, BB; Julia, J; Nyblade, AA; Durrheim, RJDate:Sep 2009The Far West Rand mining district is known for its deep gold mines and the associated high levels of seismic activity. Thousands of tremors are recorded every day by geophones installed in the mine workings. These events range in total magnitude ...Read more