Global Earth Magnetic Anomaly Grid at 2-Arc-Minute Resolution

EMAG2v3 is a global magnetic anomaly grid compiled from satellite, ship, and airborne magnetic measurements. This update incorporates new track line data and uses a kriging algorithm for improved oceanic interpolation, with wavelengths over 300 km replaced by the latest satellite lithosphere magnetic field model. The grid is provided at a 2-arc-minute resolution and includes products at 4 km altitude and sea-level over oceans.

Use Cases

• Analyze magnetic anomalies at 2-arc-minute resolution to study geological structures and tectonic plate boundaries.
• Apply the kriging algorithm methodology to model heterogeneous magnetic data distributions for geophysical research.
• Integrate the satellite-derived lithosphere magnetic field model (MF7) for wavelengths over 300 km into regional magnetic studies.
• Compare magnetic intensity between the 4 km altitude grid and the sea-level oceanic grid to assess altitude-dependent variations.

Strengths

• Global spatial coverage integrating data from land and oceanic regions.
• High-resolution grid at 2 arc-minutes, supported by an additional sea-level product for oceans.
• Compilation methodology prioritizes original shipborne and airborne data over precompiled grids for accuracy.
• Incorporates the latest satellite lithosphere magnetic field model (MF7) for long-wavelength components.

Limitations

• Specific temporal coverage for the source measurements is not provided, limiting time-series analysis.
• The reliance on interpolation, such as kriging for sparse oceanic tracks, may introduce model-dependent artifacts in those regions.
• Lack of detailed metadata on individual data sources (e.g., specific satellite missions, survey dates) may complicate provenance tracking for advanced users.

Provenance

Source

National Oceanic and Atmospheric Administration, Department of Commerce.

Collection Method

Compiled from satellite, ship, and airborne magnetic measurements; oceanic interpolation uses a kriging algorithm.

Freshness

Last updated on 2024-10-18.

Geography

Global.