Please note: You are viewing the unstyled version of this website. Either your browser does not support CSS (cascading style sheets) or it has been disabled. Skip navigation.

Mark L. Roberts

  Email    Print  PDF  Change text to small (default) Change text to medium Change text to large

Related Files

» Curriculum Vitae (pdf)

» Publications (pdf)

Senior Research Specialist
Geology & Geophysics

» Curriculum Vitae (pdf)
» Publications (pdf)
» View Profile

Mark Roberts, staff physicist is working on an initiative to re-determine the 14C half-life. This initiative was developed in response to questions raised by various researchers at Lamont-Doherty Earth Observatory (Broecker, 2005; Fairbanks, 2005; Chiu, 2007), who pointed to uncertainties about the validity of the 'accepted' 14C half-life. These groups suggested that the currently accepted half-life of 5700 ± 30 years might be too low. A significant shift in the 14C half-life would impact our understanding of the 14 C calibration curve. Preliminary results, in which the 14C half-life is determined from knowledge of both the specific-activity and 14C/12C ratio of the 14C counting standard OX-I, indicate that the currently accepted half-life might actually be 1-2% too high. A paper summarizing the work has been recently accepted for publication in Radiocarbon.

Broecker W and Barker S, (2005) ‘A 190 per mil drop in atmosphere’s Δ14C during the “Mystery Interval” (17.5 to 14.5 kyrs)?’, submitted to Quaternary Science Reviews.

Fairbanks RG, Mortlock RA, Chiu T-C, Cao L, Kaplana A, Guilderson TP, Fairbanks TW, Bloom AL, Grootes PM, and Nadeau M-J, (2005) ‘Radiocarbon calibration curve spanning 0 to 50,000 years BP based on paired 230Th/234 U/238 U and 14C dates on pristine corals, Quaternary Science Reviews 24, 1781–1796.

Chiu T-C, Fairbanks RG, Cao L, and Mortlock RA, (2007) ‘Analysis of the atmospheric 14C record spanning the past 50,000 years derived from high-precisions 230Th/244U/238U, 231Pa/235U and 14C dates on fossil corals’, Quaternary Science Reviews 26, 18-36

Last updated: February 25, 2015

whoi logo

Copyright ©2007 Woods Hole Oceanographic Institution, All Rights Reserved, Privacy Policy.
Problems or questions about the site, please contact
Site Map | Privacy Statement | Contact | WHOI Home Page