Rapid paleomagnetic fluctuations in the Arctic and Northern Canada during the Holocene: preliminary results
Abstract
The subject of my PhD project focusses on rapid fluctuations of the Earth Magnetic Field in the Arctic during the Holocene (last 12 000 years). Recent studies have shown spectacular variations of the Earth Magnetic Field during the last century. The North Magnetic Pole (NMP) which stayed in the Canadian Arctic for the last 400 years recently migrated to the Arctic Ocean towards Siberia, with an important increase of its migration velocity. A decrease of the geomagnetic field intensity is also observed and the migration of the NMP takes place between two zones of strong intensity called “geomagnetic flux lobes” which role in the geomagnetic field variations is still uncertain. These recent changes raised important questions: are these changes the first signs of large-scale changes ? The main objective of my project is to place these recent changes in a longer geological context in order to determine if these changes are extraordinary or if they are part of the recurrent paleomagnetic variations during the Holocene. I use marine and lacustrine sediment cores from the Arctic and Northern Canada to reconstruct the variations of the paleomagnetic field. The different established records will be compared to other various records in the Arctic and Northern hemisphere to find similitudes and differences of spatial and temporal paleomagnetic variations. Magnetometers enabled to conduct continuous and discrete paleomagnetic measurements in order to reconstruct records of the full paleomagnetic vector (relative paleointensity, inclination, declination) and to characterize the granulometry and mineralogy of the magnetic minerals. The preliminary results indicate good quality data. Comparison of the relative paleointensity, inclination and declination records with geomagnetic models and reference paleomagnetic records reveals good correlation. Data analysis and processing are still in progress in order to optimize the cores stratigraphy and to try to interpret the paleomagnetic results in terms of geomagnetic flux lobe dynamics
Speaker's bio
I’m a PhD student at the Institut des sciences de la mer de Rimouski (ISMER) in Québec (Canada) since November 2021, under the supervision of Guillaume St-Onge, Jean-Carlos Montero-Serrano and Pierre Francus. I am working on paleomagnetic fluctuations in the Arctic and Northern Canada from marine and lacustrine sediment cores collected in Nares Strait, Northeastern Greenland coast, Northern Baffin Bay and Grand Lake (Labrador). Before that, I did my master in France and I was working on sediment cores from the IODP Expedition 339 in the Gulf of Cadiz, to study contourites deposits and paleoceanography of the Mediterranean Outflow Water. I’m interested in sedimentology, paleomagnetism, paleoceanography and oceanography in general.
