Late Holocene Paleomagnetic Secular Variation in the Chukchi Sea, Arctic Ocean ...

• Main Authors: West, G, Nilsson, A, Geels, A, Jakobsson, M, Moros, M, Muschitiello, F, Pearce, C, Snowball, I, O’Regan, M
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union (AGU) 2022
• Subjects: 3709 Physical Geography and Environmental Geoscience; 37 Earth Sciences; 3703 Geochemistry; 3705 Geology; 3706 Geophysics; 13 Climate Action; Arctic; Arctic Ocean; Chukchi Sea; Chukchi; Alaska
• Online Access: https://dx.doi.org/10.17863/cam.84361; https://www.repository.cam.ac.uk/handle/1810/336940

AbstractThe geomagnetic field behavior in polar regions remains poorly understood and documented. Although a number of Late Holocene paleomagnetic secular variation (PSV) records exist from marginal settings of the Amerasian Basin in the Arctic Ocean, their age control often relies on a handful of radiocarbon dates to constrain ages over the past 4,200 years. Here we present well‐dated Late Holocene PSV records from two sediment cores recovered from the Chukchi Sea, Arctic Ocean. The records are dated using 26 14 C measurements, with local marine reservoir corrections calibrated using tephra layers from the 3.6 cal ka BP Aniakchak eruption in Northern Alaska. These 14 C‐based chronologies are extended into the post‐bomb era using caesium‐137 dating, and mercury isochrons. Paleomagnetic measurements and rock magnetic analyses reveal stable characteristic remanent magnetization directions, and a magnetic mineralogy dominated by low‐coercivity minerals. The PSV records conform well to global spherical harmonic ...