Geophysics is the study of the Earth by quantitative physical methods – principally by measuring the gravitational, magnetic, electrical, and seismic-velocity properties of the Earth’s surface and interior. Different rocks have different properties - measuring these differences provides information about the distribution and the structure of the rocks on the surface and at depth.  SGS uses geophysical methods to more effectively explore for mineral and water resources, as well as to provide data for geotechnical and environmental studies.  This is done in conjunction with SGS projects and also for clients that include other government departments and the private sector.
Contract Survey Work
SGS has experienced staff to carry out all types of ground geophysical surveys for shallow investigations, including processing the data and some interpretation.  The area that can be covered and rate of data acquisition depend greatly on the types of methods employed as well as the nature of the terrain.  Hence we provide a realistic estimate of the time and costs involved for each project.
Types of Surveys and Available Equipment
•  Gravity surveys – Scintrex CG3 and CG5 (2), Lacoste and Romberg EG Graviton meters
•  Magnetic surveys – Geometrics G856 proton (2) and G858 caesium magnetometers.
•  Electrical surveys – Iris Instruments 96-channel Syscal Pro and ElrecT systems
•  Electromagnetic surveys – Zonge TEM and nanoTEM system
•  Radiometric surveys – Exploranium GR-320 meter 
•  Shallow seismic surveys – Geometrics 96-channel Geode system with ES200T source
•  Ground penetrating radar surveys – GSSI SIR-3000 system
•  Borehole surveys – Mount Sopris system with various probes
Radiometric data
SGS has radiometric (U, K, Th) grids covering part of the Phanerozoic rocks adjacent to the Arabian shield, and regional and U, K, Th grids for some parts of the shield.  Please contact us for details of this data.
Regional Aeromagnetic Data
Airborne regional magnetic surveys cover outcropping Precambrian rocks in the western part of Saudi Arabia (the Arabian Shield), Phanerozoic sedimentary rocks to the east and north of the shield (the “Cover rocks”), and parts of the Red Sea basin.  These surveys were regional in nature, with nominal survey altitudes that were up to 300 m above the ground, and are very useful in showing structural and lithlogical trends across the shield.  The survey data have been merged to provide composite magnetic grids for the central and western parts of the country that are available from SGS in the form of Total Magnetic Intensity and Reduced to the Pole (RTP) grids as well as several derivatives of the RTP.  The complete area is available as a 200 m Lambert Cartesian grid, and magnetic grids are also available for more localized areas in UTM coordinates.  Please contact SGS for details of the coverage and costs of the grids, which also depend on the coverage required.77.jpg