How to use Cal Pal Online: Enter a date above and click "Calibrate".Dates between 50.000 and 1 BP will be calibrated using the calibration curve Cal Pal2007_HULU.Extension of the C record beyond the 0 to 11,900 year long tree ring record is well underway, being measured in many different archives, and undoubtedly an enormous amount of scientific knowledge will stem from these studies.In our laboratory, we have overlapped and extended the tree-ring radiocarbon calibration from 3,000 to 55,000 yrs.BP stands for “Before Present” or “Before Physics” as some would refer to it.It should be noted that a BP notation is also used in other dating techniques but is defined differently, as in the case of thermoluminescence dating wherein BP is defined as AD 1980.

Details C concentrations are mainly due to variations in the rate of radiocarbon production in the atmosphere, caused by changes in the Earth's magnetic field and variability in solar activity, and changes in the carbon cycle.BP using coral samples from our offshore coral reef core collections from Barbados (13.10°N; 59.32°W) in the western tropical Atlantic and Kiritimati Atoll (1.99°N, 157.78°W) in the central equatorial Pacific, and from the uplifted reefs of Araki Island (15.63°S; 166.93°E) in the western Pacific.In addition, we have reanalyzed the radiocarbon and U age dates from our earlier radiocarbon calibration work using new pretreatment and analytical techniques and state-of-the-art instrumentation at higher precision; we report these new results in this WEB site and in Fairbanks et al., (2005).Please report bugs and send suggestions to: [email protected] read the scientific article on the carbon dating done on the Jericho site written by Bruins and Van Der Plicht.Cal Pal-Online is developed to give a quick reference.For more detailed results, graphical output and different 14C calibration methods, download and use Cal Pal-Beyond the Ghost.