Your query was: kletetschka

HR: 0800h
AN: GP11C-0846
TI: Detecting ultra-low magnetic fields with common magnetic minerals
AU: * Kletetschka, G
EM: gunther.kletetschka@gsfc.nasa.gov
AF: NASA, Goddard Space FLight Center, Code 691, Greenbelt, MD 20771 United States
AU: * Kletetschka, G
EM: gunther.kletetschka@gsfc.nasa.gov
AF: Catholic University of America, Department of Physics, Washington, DC 20064 United States
AU: * Kletetschka, G
EM: gunther.kletetschka@gsfc.nasa.gov
AF: Academy of Sciences, Institute of Geology, Prague, 16502 Czech Republic
AU: Wasilewski, P J
AF: NASA, Goddard Space FLight Center, Code 691, Greenbelt, MD 20771 United States
AU: Kohout, T
AF: Academy of Sciences, Institute of Geology, Prague, 16502 Czech Republic
AU: Kohout, T
AF: University of Helsinki, Division of Geophysics, Department of Physical Sciences, Helsinky, 00014 Finland
AU: Kohout, T
AF: Charles University, Department of Applied Geophysics, Faculty of Natural Sciences, Prague, 12843 Czech Republic
AU: Herrero-Bervera, E
AF: University of Hawaii at Manoa, SOEST-HIGP, 1680 East West Road, Honolulu, HI 96822 United States
AU: Fuller, M D
AF: University of Hawaii at Manoa, SOEST-HIGP, 1680 East West Road, Honolulu, HI 96822 United States
AB: Growing volume of extraterrestrial material is being used to analyze magnetic paleo-intensities. They are important for estimation of paleo-fields that once existed in extraterrestrial environment. The extraterrestrial field can be several orders of magnitudes weaker than a terrestrial field. The data demonstrating that the TRM linear acquisition is valid for such low fields are virtually not existent. We tested the linear relation ship of the thermal remanent magnetization (TRM) acquisition in extremely week fields ranging from 1 nT to 100,000 nT. We used multidomain samples of hematite, magnetite, and iron. We also used mineral assemblages containing mixtures of these minerals. Our results indicate that multidomain material did not record magnetic fields below 1,000 nT. Assemblages carrying single domain (SD) material did record fields as low as 3 nT. When assemblages contain a magnetic phase with blocking temperature higher than the blocking temperatures of the rest of the magnetic minerals within the assemblage it can be detected by deviation from the linear magnetic acquisition. Our results provide rare experimental data for TRM acquisition in fields below 1000 nT.
DE: 5440 Magnetic fields and magnetism
DE: 3660 Metamorphic petrology
DE: 2134 Interplanetary magnetic fields
DE: 1519 Magnetic mineralogy and petrology
DE: 1521 Paleointensity
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2004 AGU Fall Meeting