Paleomagnetism of abbott seamount and implications for the latitudinal drift of the Hawaiian Hot Spot

Abstract

The magnetic anomaly of Abbott Seamount, located near the Hawaiian‐Emperor bend, has been analyzed for its paleomagnetic information. Short‐wavelength “noise” components of the anomaly, assumed to result from small magnetization inhomogeneities or reversals in the upper layers of the volcano, were filtered out by upward continuation. The polarity of the bulk of the seamount is reversed, and its virtual geomagnetic pole is located at 75.5°N, 4.6°E. This pole lies close to Pacific paleomagnetic poles of late Eocene age and is consistent with the age of the edifice to be expected from its position in the Hawaiian chain. The paleolatitude of the seamount, 17.5°N±4.4°, is not significantly different from the present latitude of the Hawaiian hot spot, approximately 19.5°N. This finding implies that the Hawaiian hot spot (and by inference other hot spots) has remained relatively fixed with respect to the spin axis since the Eocene. However, other paleolatitudes from the Hawaiian‐Emperor chain suggest that systematic variation of the hot spot's latitude may have occurred. Comparison of the Hawaiian‐Emperor paleolatitude data with paleomagnetic data from central Pacific piston cores and with north Pacific paleoequator data from Deep Sea Drilling Project cores indicates that the apparent latitude drift since the Eocene has been largely the result of long‐term nondipole components in the geomagnetic field rather than relative motion between the hot spot and the spin axis. Conversely, the variation that occurred prior to the Eocene appears to contain a significant amount of such motion coupled with an indeterminate amount of nondipole effect.