HR: 08:05h
AN: U31B-01    [Abstracts]
TI: Jan Hospers' development of the geocentric axial dipole hypothesis and defense of field reversals
AU: * Frankel, H
EM: frankelh@umkc.edu
AF: University of Missouri - Kansas City, Department of Philosophy, 222 CH, UMKC, Kansas City, MO 66208 United States
AB: When Jan Hospers arrived at Cambridge in 1949 he already had planned to use paleomagnetism as a stratigraphic tool to investigate Icelandic lava flows during summer 1950. He did not, however, plan to work on the problem of reversals or use paleomagnetism to test continental drift. At the time he did not know about reversals, and he thought continental drift was a relic of past geological thought. Although Ben Browne remained Hospers' official supervisor, Keith Runcorn, who arrived at Cambridge in January 1950, became his mentor. He encouraged Hospers and provided key contacts. Hospers returned with 22 samples from his first collecting trip. He observed that approximately half his samples were reversely magnetized, that they appeared to be clustered around the axis of rotation, and that he needed a statistical procedure for reducing the observed scatter. Runcorn asked R. A. Fisher to help with the statistics. Fisher developed the statistical analysis, and Hospers (1951) argued for field reversals and the geocentric axial dipole hypothesis (GAD). Runcorn encouraged Hospers to obtain samples from Northern Ireland and to return to Iceland. Hospers' new work led him to make two firm and important contributions to paleomagnetism. Hospers (1953-1954) offered the first extensive empirical support for serial reversals and GAD. His support for field reversals included a thorough discussion of L. N\'{e}el's self-reversal hypotheses. The empirical support he marshaled in favor of GAD, which extended back through the Miocene, provided a firm base on which K. Creer, E. Irving, Runcorn, and other paleomagnetists could present arguments favoring mobilism. He also constructed a rudimentary polarity time scale.
DE: 1714 Geomagnetism and paleomagnetism
DE: 1527 Paleomagnetism applied to geologic processes
SC: Union [U]
MN: 2004 AGU Fall Meeting