TOWARDS AN UNDERSTANDING OF PALEOMAGNETIC SECULAR VARIATION: OBSERVATIONS FROM THE NORTH ATLANTIC, IMPLICATIONS FOR THE WORLD?

A new Paleo-and-Environmental Magnetism Laboratory at Oregon State University is being built around the unique capabilities of a super-conducting rock magnetometer optimized for u-channel samples. The primary focus of the lab is sediment magnetism, with a significant goal being the reconstruction of geomagnetic field dynamics. To underscore the possibilities, I will present high-quality, extremely well-dated directional paleomagnetic secular variation (PSV) records from Holocene sediments of the northern North Atlantic [Kristensdottir et al., 2007; Stoner et al., 2007]. Core MD99-2269 (latitude 66°37.53 N, longitude 20°51.16W, water depth 365 m, length 2533 cm) was raised from the north Iceland shelf and core MD99-2322 (latitude 67°08.18 N, longitude 30°49.67 W, water depth 714 m, length 2617 cm) was taken from the deepest part of the Kangerlussuaq Trough, SE Greenland shelf. Accumulation rates of these sediments are >2m/kyr, high enough to minimize temporal and/or smoothing artifacts induced by the magnetic acquisition process. These records are beginning to fill a long-held paleomagnetic data gap, providing remarkable documentation of both high-amplitude features and abrupt geomagnetic change. In this presentation, I will touch upon the potential of these PSV records through a comparison with records from North America and Europe. Implications for stratigraphy, geomagnetic dynamics, geomagnetic shielding, and the influence of a changing geomagnetic shield on Earth's surface environment will be explored.