In situ produced 14C by cosmic ray muons in ablating Antarctic ice

Samples of a core (52 m) of ablating Antarctic ice were analysed for 14 CO and 14 CO 2 by accelerator mass spectrometry. The data were compared with a 14 C in situ production model that includes muon capture in addition to oxygen spallation by neutrons. The analysis reveals significant in situ 14 C at depths below 10 m, which we attribute to 14 C production by cosmic ray muons. The age of the ice was determined as 9.3±0.4 14 C ka BP. DOI: 10.1034/j.1600-0889.2002.00274.x