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Magnetic Anomaly Map of North America

A New Magnetic Anomaly Map of North America

North America Maganetic Anomaly Map
United States
U.S. Digital Data
Case Studies

Outline of North American continent with identifiers for Canadian, U.S., and Mexican participating agencies.

The digital magnetic anomaly database and map for the North American continent is the result of a joint effort by the Geological Survey of Canada (GSC), U.S. Geological Survey (USGS), and Consejo de Recursos Minerales of Mexico (CRM). This integrated, readily accessible, modern digital database of magnetic anomaly data is a powerful tool for further evaluation of the structure, geologic processes, and tectonic evolution of the continent and may also be used to help resolve societal and scientific issues that span national boundaries. The North American magnetic anomaly map derived from the digital database provides a comprehensive magnetic view of continental-scale trends not available in individual data sets, helps link widely separated areas of outcrop, and unifies disparate geologic studies.

The group created three unique, gridded data sets used to make the magnetic anomaly map of North America. Details on the data processing and compilation procedures used to produce the grids are described in the booklet that accompanies the North American magnetic anomaly map. The first grid shows the magnetic field at 305 meters above terrain. For the second grid we removed long-wavelength anomalies (500 km and greater) from the first grid. This grid was used for the published map. The third grid uses an equivalent source method, based on long-wavelength characterization using satellite data, to correct for spurious shifts in the original magnetic anomaly grid. Further details on the grids are described in the open-file report listed below.

North American Magnetic Anomaly Group (NAMAG)

Viki Bankey Patricia Hill Victoria Rystrom
Alejandro Cuevas Robert Kucks Sarah Shearer
David Daniels Warner Miles Stephen Snyder
Carol A. Finn Mark Piulkington Ronald Sweeney
Israel Hernandez Carter Roberts Julio Velez
  Walter Roest  

Products for the North American Magnetic Anomaly Database and Grids

Printed Map and Booklet

Outline of North American continent with identifiers for Canadian, U.S., and Mexican participating agencies.


Hard Copy: order directly from

USGS Information Services
Box 25286
Denver Federal Center
Denver, CO 80225
Tel: 888-ASK-USGS; Fax: 303-202-4693

Gridded Data


DVD: Available after November 2002 from USGS Information Services

Mineral Resources Program
Eastern Central GMEG Alaska Minerals Information Crustal Geophysics and Geochemistry Spatial Data