HR: 0800h
AN: GP31A-0832    [Abstracts]
TI: Estimating Antarctic near-surface magnetic anomalies from Oersted and CHAMP satellite magnetometer observations
AU: von Frese, R R
EM: vonfrese@geology.ohio-state.edu
AF: Dept. of Geological Sciences, The Ohio State Univ. 271 Mendenhall Lab, Columbus, OH 43210 United States
AU: * Kim, H
EM: kimhr@core2.gsfc.nasa.gov
AF: Goddard Earth Sciences and Technology Center, UMBC, Code 921, Goddard Space Flight Center,NASA , Greenbelt, MD 20771 United States
AU: Gaya-Pique, L R
EM: pique@ingv.it
AF: Istituto Nazionale di Geofisica e vulcanologia, Via di Vigna Murata,, Rome, 00143 Italy
AU: Taylor, P T
EM: Patrick.Taylor@nasa.gov
AF: Geodyanmics Branch, Code 921, Goddard Space Flight Center,NASA, Greenbelt, MD 20771 United States
AU: Golynsky, A V
EM: sasha@viino.nw.ru
AF: VIINOkeangeologia, 1 Angliysky Ave., St. Petersburg, 190121 Russian Federation
AU: Kim, J
EM: jwkim@sejong.ac.kr
AF: Dept. of Geoinfo. Eng., The Sejong Univ. Kunja-dong, Kwangjin-ku, Seoul, 143-747 Korea, Republic of
AB: Significant improvement in predicting near-surface magnetic anomalies can result from the highly accurate magnetic observations of the CHAMP satellite that is orbiting at about 400 km altitude. In general, regional magnetic signals of the crust are strongly masked by the core field and its secular variations due to wavelength coupling in the spherical harmonic representation and thus are difficult to isolate in the satellite measurements. However, efforts to isolate the regional lithospheric from core field components can exploit the correlations between the CHAMP magnetic anomalies and the pseudo magnetic effects inferred from gravity-derived crustal thickness variations. In addition, we can use spectral correlation theory to filter the static lithospheric field components from the dynamic external field effects. Employing these procedures, we processed the CHAMP magnetic observations for an improved magnetic anomaly map of the Antarctic crust. Relative to the much higher altitude Oersted and noisier Magsat observations, CHAMP magnetic anomalies at 400 km altitude reveal new details on the effects of intra-crustal magnetic features and crustal thickness variations of the Antarctic. Moreover, these results greatly facilitate predicting magnetic anomalies in the regional coverage gaps of the ADMAP compilation of Antarctic magnetic anomalies from shipborne, airborne and ground surveys. Our analysis suggests that considerable new insights on the magnetic properties of the lithosphere may be revealed by a further order-of-magnitude improvement in the accuracy of the magnetometer measurements at minimum orbital altitude.
DE: 9310 Antarctica
DE: 1500 GEOMAGNETISM AND PALEOMAGNETISM
DE: 1517 Magnetic anomaly modeling
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2004 AGU Fall Meeting