Improved magnetic anomalies of the Antarctic lithosphere from satellite and near-surface data

• Published in: Geophysical Journal International
• Main Authors: Kim, Hyung Rae, von Frese, Ralph R. B., Taylor, Patrick T., Golynsky, Alexander V., Gaya-Piqué, Luis R., Ferraccioli, Fausto
• Other Authors: Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: ADMAP; Antarctic magnetic anomalies; near-surface surveys; satellite surveys; [SDU]Sciences of the Universe [physics]; Antarctic; The Antarctic; Antarc*
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-03603176; https://hal-insu.archives-ouvertes.fr/insu-03603176/document; https://hal-insu.archives-ouvertes.fr/insu-03603176/file/171-1-119.pdf; https://doi.org/10.1111/j.1365-246X.2007.03516.x

International audience The Antarctic magnetic anomaly map compiled marine and airborne surveys collected south of 60°S through 1999 and used Magsat data to help fill in the regional gaps between the surveys. Ørsted and CHAMP satellite magnetic observations with greatly improved measurement accuracies and temporal and spatial coverage of the Antarctic, have now supplanted the Magsat data. We combined the new satellite observations with the near-surface survey data for an improved magnetic anomaly map of the Antarctic lithosphere. Specifically, we separated the crustal from the core and external field components in the satellite data using crustal thickness variations estimated from the terrain and the satellite-derived free-air gravity observations. Regional gaps in the near-surface surveys were then filled with predictions from crustal magnetization models that jointly satisfied the near-surface and satellite crustal anomalies. Comparisons in some of the regional gaps that also considered newly acquired aeromagnetic data demonstrated the enhanced anomaly estimation capabilities of the predictions over those from conventional minimum curvature and spherical harmonic geomagnetic field models. We also noted that the growing number of regional and world magnetic survey compilations involve coverage gaps where these procedures can contribute effective near-surface crustal anomaly estimates.