HR: 08:00h
AN: PP11A-01    [Abstracts]
TI: Observations on the Late Holocene Dynamics of the Boreal Geomagnetic Field From Ellesmere Island Lake Sediments
AU: * Stoner, J S
EM: jstoner@coas.oregonstate.edu
AF: Oregon State University, College of Ocean and Atmospheric Sciences, 104 Ocean Admin, Corvallis, OR 97330, United States
AU: Davies, M H
EM: mdavies@coas.oregonstate.edu
AF: Oregon State University, College of Ocean and Atmospheric Sciences, 104 Ocean Admin, Corvallis, OR 97330, United States
AU: Bradley, R S
EM: rbradley@geo.umass.edu
AF: University of Massachusetts, Department of Geosciences, Morrill Science Center, Amherst, MA 01003-9297, United States
AU: Cook, T L
EM: tcook@geo.umass.edu
AF: University of Massachusetts, Department of Geosciences, Morrill Science Center, Amherst, MA 01003-9297, United States
AU: Francus, P
EM: pfrancus@ete.inrs.ca
AF: Institut national de la recherche scientifique, Centre Eau, Terre et Environnement, 490 rue de la couronne, Québec, Qué G1K 9A9, Canada
AU: Besonen, M R
EM: besonen@geo.umass.edu
AF: University of Massachusetts, Department of Geosciences, Morrill Science Center, Amherst, MA 01003-9297, United States
AU: Channell, J E
EM: jetc@geology.ufl.edu
AF: University of Florida, Department of Geological Sciences, Gainesville, FL 32611, United States
AU: St-Onge, G
EM: guillaume_st-onge@UQAR.QC.CA
AF: Université du Québec à Rimouski, Institut des sciences de la mer de Rimouski, 310, allée des Ursulines, Rimouski, Qué G5L 3A1, Canada
AB: The geomagnetic field of the Arctic is complex, poorly understood and a key component of the global system. A prominent feature of the Boreal geomagnetic field is the accelerated motion of the North Magnetic Pole (NMP) away from North America having moved more than 1600 km in the last century. Here we present sediment paleomagnetic observations from Ellesmere Island lakes, calibrated by 400-year historic geomagnetic record, that allow us to constrain polar motion and begin to assess the geomagnetic dynamics that drive these changes over the last several thousand years. Our primary data sets are derived from two Ellesmere Island lakes (Sawtooth Lake, 79.21 N, 83.56 W and Lower Murray Lake, 81.34 N, 69.54 W) that preserve strong, stable, single component remanent magnetizations and possess independently derived varve based chronologies. U-channel paleomagnetic data obtained from multiple cores taken from each lake allow the development of composite directional secular variation and relative paleointensity records. These observations are supported by paleomagnetic data from other Canadian Arctic Archipelago lakes that lack either independent age control or replicate-coring. These data demonstrate that the Arctic geomagnetic field over the late Holocene is dominated by the same complex boundary conditions that influence the historic record including intensity variations of the high latitude flux patches and the westward drift of the polar geomagnetic vortex. The ongoing motion of the NMP appears to reflect the continuation of a millennial scale Late Holocene oscillation that is part of a significant geomagnetic change.
DE: 1520 Magnetostratigraphy
DE: 1521 Paleointensity
DE: 1522 Paleomagnetic secular variation
DE: 1560 Time variations: secular and longer
DE: 4207 Arctic and Antarctic oceanography (9310, 9315)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2009 Joint Assembly