Holocene Paleomagnetic Secular Variation and Paleointensity: Influence of High Latitude Flux Lobes on the Tangent Cylinder

Abstract:

Longitudinal comparisons of high quality, high resolution and independently dated archeomagnetic and paleomagnetic secular variation (PSV) records from the NE Pacific (Alaska & Hawaii), North America, North Atlantic, and Europe during the Holocene show generally coherent multi-centennial to millennial scale variations of specific PSV parameters. These observations illustrate two primary modes (although there are likely others), which we have so far called the European and North American modes after anomalous flux concentrations (lobes) in the late Holocene and historical time average field. Here we explore how mode variations translate into the tangent cylinder. Comparisons of high resolution paleomagnetic records derived from a series of cores retrieved from two Ellesmere Island lakes (Sawtooth Lake, 79º21 N, 83º56 W and Lower Murray Lake, 81°34 N, 69°54 W) with varve based chronologies allow us to define regional PSV and paleointensity (PI) patterns for the last 5kyr. Although Ellesmere Island PSV and PI are distinct from those observed at mid to high latitudes of North America, we observe consistencies in timing with the primary oscillations that at least partially illustrate how variations in the tangent cylinder compare with those at mid-latitudes. We find that Ellesmere Island PIs are weak and VGPs migrate towards the axis of rotation during times when European PIs are strong (European Mode), whereas high North American PIs (North American Mode) are associated with significant changes in Ellesmere Island VGP longitudes. Relative highs in Ellesmere Island PIs are temporally distinct from the timing of the other two. A repeating progression of PI highs are observed, showing than geomagnetic behavior in the tangent cylinder is distinct from, but influenced by large scale oscillations in flux observed at mid to high latitudes.