Geomagnetic Modulation of the 36 Cl Flux in the GRIP Ice Core, Greenland

• Published in: Science
• Main Authors: Baumgartner, S., Beer, J., Masarik, J., Wagner, G., Meynadier, L., Synal, H.-A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 1998
• Subjects: Multidisciplinary; Greenland; Greenland ice core; Greenland Ice core Project; GRIP; ice core
• Online Access: http://dx.doi.org/10.1126/science.279.5355.1330; https://www.science.org/doi/pdf/10.1126/science.279.5355.1330

Geomagnetic field strength is expected to affect the production rate of cosmogenic isotopes such as beryllium-10, carbon-14, or chlorine-36. Chlorine-36 data from the Greenland Ice Core Project (GRIP) ice core agree well with a production rate calculation based on a paleomagnetic reconstruction for the past 100,000 years over both long- and short-term variations. A chlorine-36 peak at 38,000 years ago previously found in the beryllium-10 record from the Vostok ice core can be explained by a period of low geomagnetic field intensity.