Airborne Geophysical Surveys Aiding Governments and Explorers

Edited by Admin
Geophysical CompaniesGeophysical companies conduct efficient geophysical explorations for governments, individuals, mapping professionals, mining companies and others who who depend upon geoscientific data.
Some of the applications are indicated below:
  • Mineable magnetic ores
  • Carbon (Graphite)
  • Underground reservoirs
  • Hydrocarbons
  • Uranium
  • Base and Precious Metals
Efficient geophysical exploration surveys employ the use of precise airborne geophysical data acquisition systems to ensure that the data obtained during a survey is highly precise and dependable as required for successful exploration.
The majority of geophysical exploration surveys are conducted using airborne geophysical survey methods and as such, can represent significant financial investments. Therefore, governments and mining companies choose proven, specialist companies, such as Terraquest, to achieve complex survey goals.
A professional geophysical company will be able to deploy highly developed data acquisition systems and conduct geophysical surveys such as airborne magnetics, electromagnetics and radiometrics.
Instead of using a standard aircraft to conduct an airborne geophysical survey, an advanced geophysical company will employ the use of a specially modified aircraft that has been specifically prepared for the purpose of conducting airborne surveys.
Geophysical companies are able to offer fixed wing aircraft that can conduct high resolution and detailed surveys. Using methods such as pre-planned drape flying, it is possible to greatly enhance the precision and quality of the data acquired during an airborne survey. Pre-planned drape flying allows for consistent line-to-line correlation at intersections of traverse and tie lines. It also enables the surveyor to better control the exact positioning of the aircraft, leading to better quality data.
Airborne magnetic surveys are the most commonly employed type of airborne geophysical surveys. There are two basic categories for airborne magnetic surveys: regional surveys and detailed surveys.
A regional survey will acquire data at a lower resolution due to a wider traverse line spacing of over 500 meters. This type of geophysical survey will typically cover at least 5,000 square kilometres and is used a means of creating maps and developing perspective on the concentration of nonmetallic resources such as petroleum and coal. A regional survey is conducted as well for tectonic studies.
As indicated by the name, detailed surveys acquire higher resolution data targeting specific magnetic minerals that are present in particular areas the Earth's crust . As such, detailed surveys are capable of providing valuable data for mining companies, and can act as a means of prospecting early on in the  exploration process.
A detailed survey will indicate where there are highly concentrated areas of magnetic mineral ores, such as magnetic iron ores. These surveys can also be carried out as a means of indicating basement targets for hydrocarbon exploration.
Airborne geophysical exploration companies provide highly effective means of exploring terrain for mineral prospects. The sophistication of the data acquisition systems, combined with specially modified aircraft, make geophysical companies an important instrument in mapping lithologies and mineral prospecting.
As the process of collecting geophysical data can be costly, it is important to work with a survey company that has proven procedures for dealing with factors that can possibly interfere with the collection of quality data. Factors such as "geological noise” can conceal survey exploration targets. The following factors can cause geological noise in a geophysical survey:
  • Serpentinized ultramafics with magnetite bands
  • Metamorphosed country rock with graphite bands
  • The possible lateral variations that can be found in conductive overburden
  • Existence of clay in rocks or water
Electromagnetic surveys are used to address the above. This method employs the use of an alternating electric current that is passed through a transmitter coil that will create a primary electromagnetic field that penetrates into the subsurface. The magnetic component of the EM field penetrating through ground  induces alternating currents or "eddy currents" to flow within the conductor in the presence of a conducting orebody.  The eddy currents generate their own secondary EM field distorting the primary field.  The airborne electromagnetic receiver responds to the resultant of arriving primary and secondary fields so that the response differs in phase, amplitude, and direction from the response to the primary field. These differences between transmitted and received EM field reveal the presence of a conductor and provide information on its geometry and electrical properties. The depth of penetration of an EM field depends on its frequency and the conductivity of the geology through which it is propagating.
Specialists in Airborne Geophysical Surveys
Terraquest was established in 1984 and since then, our dedicated team has flown over 1,500 airborne geophysical surveys using both fixed wing and helicopter platforms.  Our professional crews provide significant experience having carried out airborne magnetic surveys, airborne gravity surveys, airborne radiometric surveys, and airborne electromagnetic surveys on five continents.
Our quality data sets have been utilized in the exploration for base and precious metals, kimberlite, hydrocarbons, uranium, rare earth minerals and water.  The company has performed exemplary surveys for both small and large exploration groups as well as many government agencies.  References can be provided upon request. Visit



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