Verification of the crustal component in satellite magnetic data

Abstract

To investigate the utility of satellites for mapping crustal magnetic anomalies, POGO (Polar Orbiting Geophysical Observatory) and preliminary MAGSAT magnetometer data are compared with scalar aeromagnetic data obtained by the U.S. Naval Oceanographic Office (NOO)‐Vector Magnetic Survey of the conterminous U.S.A. POGO and available MAGSAT data demonstrate remarkable consistency over the study region. The NOO aeromagnetic data are low‐pass filtered for wavelengths larger than about 4° and spherically upward continued to 450 km elevation by equivalent point source inversion for direct comparison with POGO satellite magnetometer observations. The upward continued NOO data show that most of the energy is in the long wavelength ( ≅ 1000‐3000 km) anomalies. Removal of these wavelengths by suitable filtering reveals a residual anomaly field that corresponds well with the satellite anomalies, thus demonstrating that the satellite data are useful for mapping crustal magnetic anomalies. A number of correlations between the NOO, POGO and preliminary MAGSAT data are evident at satellite elevations, including a prominent transcontinental magnetic high which extends from the Anadarko Basin of the eastern Texas panhandle to the Cincinnati Arch. The transcontinental magnetic high is breached by negative anomalies located over the Rio Grande Rift and Mississippi River Aulacogen.