Ground Magnetic Survey Meaning

Ground magnetic surveys are a cornerstone of geophysical exploration, providing critical insight into the composition and structure of the Earth’s subsurface. By measuring variations in the Earth’s magnetic field, these surveys detect the presence of magnetic minerals and associated rock types. For industries ranging from mineral exploration to renewable energy and environmental assessment, ground magnetic surveys offer high-resolution data essential for informed decision-making.

At Metatek, our ground magnetic surveys are part of a fully integrated geophysical suite, designed to deliver precise, reliable, and actionable results. By combining magnetic data with complementary techniques such as gravity gradiometry (FTG/eFTG), hyperspectral imaging, and magnetotellurics (MT), we provide a comprehensive understanding of geological targets.

What is a Ground Magnetic Survey?

A ground magnetic survey measures variations in the Earth’s magnetic field caused by the distribution of magnetic minerals in subsurface rocks. Unlike airborne surveys, ground surveys allow for closer line spacing, providing higher resolution data capable of detecting shallow structures, faults, and mineralised zones that might otherwise go unnoticed.

Key characteristics of ground magnetic surveys include:

  • High-resolution mapping: Tighter line spacing and proximity to the source enhances the detection of shallow geological features.
  • Cost-effectiveness: Efficient coverage of areas where airborne access is limited or topography is challenging.
  • Versatility: Suitable for applications in mineral exploration, hydrocarbon prospecting, groundwater assessment, and environmental investigations.

Applications of Ground Magnetic Surveys

Ground magnetic surveys are widely used across industries for a variety of applications. At Metatek, our team advises on the optimal survey type for your objectives and integrates these results with other geophysical datasets.

Common applications include:

  • Mineral Exploration: Detection of ore bodies such as iron, copper, nickel, gold, and rare earth elements. Magnetic data helps identify faults, dykes, and intrusive structures associated with mineralisation.
  • Oil and Gas Exploration: Mapping subsurface structures, volcanic intrusions, and basement trends to support seismic interpretation and well planning.
  • Water Resource Management: Identification of aquifer structures, fault zones, and lithological boundaries influencing groundwater flow.
  • Environmental and Geo-Hazard Assessment: Mapping subsurface voids, buried metallic infrastructure, or geological features like karsts that could affect land stability.

Metatek’s Approach to Ground Magnetic Surveys

Metatek combines technical expertise, global operational experience, and bespoke software solutions to deliver high-quality survey results tailored to complex geological environments.

Survey Planning and Execution:

  • Definition of the Area of Interest (AOI) with input from legacy data and regional geological models.
  • Survey line spacing and layout optimised for target depth, resolution, and terrain.
  • Feasibility studies using forward modelling to predict detection limits and assess instrument suitability.

Data Acquisition and Quality Control:

  • High-precision magnetometers and integrated positioning systems ensure accurate data capture.
  • In-field quality control allows real-time assessment of data, ensuring that surveys meet strict accuracy standards.
  • Integration with complementary methods such as eFTG gravity gradiometry, hyperspectral imaging, and MT surveys enhances interpretation.

Advanced Processing and Interpretation:

  • Use of bespoke and industry-standard software for processing, filtering, and visualisation of magnetic data.
  • Application of transformations and derivative maps (e.g., horizontal gradient, tilt derivative) to enhance structural interpretation.
  • Quantitative interpretation supports 2D/3D modelling, fault and lineament mapping, and basement characterisation.
  • Results are integrated with gravity, MT, seismic, and geological datasets for holistic subsurface models.

Real-World Examples of Ground Magnetic Surveys

Metatek has successfully executed high-resolution ground magnetic surveys globally, demonstrating our ability to operate in challenging terrains and deliver actionable insights. For example:

  • Tampico-Misantla Basin, Mexico: Integrated iFTG and ground magnetic surveys covering 7,400 km² helped define top-basement structures and fault frameworks, supporting hydrocarbon exploration.
  • HORUS-1, Western Desert, Egypt: Airborne and ground surveys combined eFTG and magnetic data over 113,500 km², resolving basement structures and sedimentary basin architecture for onshore exploration bidding rounds.

Why Choose Metatek for Ground Magnetic Surveys and Geophysical Exploration?

Ground magnetic surveys are only as valuable as the expertise and technology behind them. At Metatek, our strengths include:

  • Global Operational Capability: Surveying in remote, rugged, and environmentally sensitive areas.
  • Integrated Geophysical Solutions: Combining magnetics with gravity, MT, hyperspectral, and LiDAR for comprehensive subsurface models.
  • Expert Team: Over 50 years of combined experience in survey design, acquisition, processing, and interpretation.
  • Bespoke Software: Proprietary tools for advanced processing, quality control, and interpretation.
  • Knowledge Transfer: Training and collaborative workflows to ensure clients fully understand the data and its applications.

Ground magnetic surveys, when conducted with precision and integrated expertise, unlock the detailed subsurface knowledge critical to exploration, resource management, and environmental planning. At Metatek, we leverage advanced technology, methodological rigour, and global experience to ensure your survey achieves maximum insight and value.

For more information on ground magnetic surveys and how Metatek can support your project, contact our team today.

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