Home , Go Back to faculty page BRUCE M. MOSKOWITZ Professor and Associate Director, Institute for Rock Magnetism PhD, 1980, University of Minnesota Research Group Web Site: Institute for Rock Magnetism Office: 291 Shepherd Labs Phone: (612) 624-1547 Fax: (612) 625-3819 Email: bmosk@...

        The field of paleomagnetism is founded on the ability of magnetic minerals in rock to record and store information about the geologic history of the Earth's magnetic field. This magnetic memory, if stored and read correctly, provides geoscientists with information relevant for solving diverse problems about our planet. Paleomagnetism is used to understand processes in the deep interior associated with generation of the geomagnetic field, the 2-3 billion year geologic history of plate motions of the continents, and even global climate changes associated with the cycles of ice ages over the past 2 million years. My research field is rock and mineral magnetism, which is concerned with the physical and chemical foundations of paleomagnetism. If paleomagnetism is concerned with reading the signal, rock magnetism attempts to determine the fidelity of the signal by studying the nature of the recording media (magnetic minerals) and the recording process (magnetic memory and its long term storage).

        My research is focused in two major areas, rock magnetism and bio-geomagnetism. In the area of rock magnetism, my research is aimed at understanding the interconnections between macroscopic magnetic behavior associated with remanence and its long term stability and the underlying micromagnetic structures of fine particles (less than 50 micrometers) of magnetite and titano-magnetite, the minerals most responsible for carrying the paleomagnetic record in rocks, sediments, and soils. Currently, this involves using high resolution magnetic force microscopy (MFM) to image and interpret micromagnetic structures in small particles, bulk single crystals, and thin films. The single crystal work provides intrinsic magnetic structures expected for magnetite based on its crystal symmetry, while the study of small particles and thin films investigates surface, shape, and stress effects that may alter the intrinsic micromagnetic structures and contribute to long-term magnetic memory.

        I am also actively involved in the study of magnetic biomaterials and the biomineralization of magnetic oxides and sulfide minerals by certain types of microorganisms. Biogenic magnetic minerals, in addition to inorganically derived magnetic phases, are another source of fine magnetic particles contributing to the magnetic record in sediments. This work is highly interdisciplinary and I collaborate with biophysicists, microbiologists, geochemists, and electron microscopists. Research in this area involves fundamental magnetic studies of the magnetic particles produced by different types of microorganisms, such as magnetotactic bacteria, and somewhat more exotic organic-inorganic nanocomposites, such as magnetoferritin. One of the main goals of this work is to use magnetic techniques to identify and discriminate between biogenic and non-biogenic magnetic phases in sediment and soil samples.

Professional Society Memberships

• American Geophysical Union (Fellow)

• Fellow, American Geophysical Union
• 1995, IT Student Board Best Instructor in Geology and Geophysics

• Dynamic Earth: An Intro to Geology
• Geohazards
• Geodynamics I
• Principles of Geophysical Exploration
• Geomagnetism and Paleomagnetism
• Geophysics Field Camp
• Seminar: Rock Paleomagnetism

• Sahu, Sanghamitra, PhD, 1997, An experimental study of the effects of stress on the magnetic properties of magnetite.

• *Carter-Stiglitz, B. M. Jackson, B. Moskowitz, (2002) Low-temperature remanence in stable single domain magnetite, Geophy. Res. Letts, 29, 10.1029/2001GL014197.
• Ozdemir, O., D.J. Dunlop, and B.M. Moskowitz, Changes in remanence, coercivity and domain state at low temperature in magnetite, (2002). Earth Planet. Sci. Lett.,194, 343-358.
• Pan, Q., Pokhil, T., and Moskowitz, B., 2002. Domain structures in epitaxial (110) Fe3O4 particles studied by MFM: J. Appl. Phys., 91,5945-5950.
• Antretter, M., Fuller,M., Scott, E., Jackson, M., Moskowitz, B., and Solheid, P., 2003. The paleomagnetic record and rock magnetism of Martian meteorite ALH84001: J. Geophys. Res. 108(E6),5049,doi:10.1029/2002JE001979
• Frankel, R.B., and B. M. Moskowitz, 2003,. Biogenic magnets, In: Magnetism: Molecules to Materials IV, edited by Miller, J. S. and Drillon, M., Wiley-VCH, Weinheim, Germany, pp. 205-231.
• B. Carter-Stiglitz, B. Moskowitz, and M. Jackson, More on the low-temperature magnetism of stable single domain magnetite: reversibility, and non-stoichiometry, Geophys. Res. Letts, L06606, doi:10.1029/2003GL019155, 2004
• Y. Yu, L. Tauxe, B. Moskowitz, Temperature dependence of magnetic hysteresis, Geochem. Geophys., Geosys., doi:10.1029/2003GC000685 ,2004
• F. Lagroix, S. K. Banerjee, B. Moskowitz, Revisiting the mechanism of reversed thermoremanent magnetization (rTRM) based on observations from synthetic titanohematite (y=0.7), J. Geophys. Res., doi:10.1029/2004JB003076, 2004.
• Anhysteretic Remanent Magnetization, in Encyclopedia of Geomagnetism and Paleomagnetism, ed. D. Gubbins and E. Herrero-Bervera, in press, 2006
• B Housen, and B. Moskowitz , Depth Distribution of Magnetofossils in Near Surface Sediments from the Blake/Bahama Outer Ridge, western North Atlantic Ocean determined by Low-Temperature Magnetism, , submitted JRG-biogeosciences, 2005

  *designates student author

• 8/2003 to 7/2007, NSF, Continuation of a Facility: Institute for Rock Magnetism
• 9/2003 to 8/2006, NSF, Facility Support: Development and Maintenance of the Magnetics