After the data form has been filled in, press the "Enter Data" button to
enter the data in the text box at the bottom of the page. Alternatively,
paste data from a spreadsheet program into the text box. There is a sample
counter which shows how many samples have been added to the text box. When
Sample entry is complete press the "Calibrate" button to perform the calibration
of the sample data.
The marine calibration incorporates a time-dependent global ocean reservoir
correction of about 400 years. To accomodate local effects, the difference
Delta R in reservoir age of the local region of interest and the model
ocean should be determined. Guidelines for the determination of Delta R
and a global dataset are available at http://calib.org/marine. The
marine calibration dataset must be selected for calibrating these samples.
INTCAL13 calibration is limited to 0-46,400 14C year BP. This dataset is
recommended for most non-marine samples. From 0-12500 cal BP it is based on
tree-ring 14C measurements. Beyond 12.5ka it is based on marine coral and
varve data. Details of the dataset construction are given in
Radiocarbon Vol. 55, 2013, pp xxxx-yyyy.
MARINE13 calibration is limited to 0-46,806 14C year BP. This datset is
recommended for most marine samples. Between 0-10500 cal BP, it is based
on a computer model of the ocean carbon exchange that used INTCAL13 input
with a mean global reservoir correction of 405 years. Beyond 10.5ka it
uses marine cora and varve data. Details of the dataset construction are given
in Radiocarbon Vol. 55, 2013, pp xxxx-yyyy.
SHCAL13 calibration is limited to 0-46,429 14C year BP. The Southern Hemisphere
dataset is based on treerings with an average offset of 43+-13 years from the
INTCAL13 dataset. Betyond 2ka BP a random effects model is used to take
account of the fact that the offset may vary slowly over time. Details of
the dataset construction are given in Radiocarbon Vol. 55, 2013, pp xxxx-yyyy.
This field must be unique for each sample entered. If you forget to change
it you will only see a plot for the last sample bearing that sample code.
Certain characters are forbidden in samples codes because of requirements
imposed by the underlying operating system. Those charactes are & / and '
For samples composed of both marine and atmospheric carbon, Mixed Marine
limits depend on the percent of marine carbon in the sample. A linear
combination of the Northern or Southern atmospheric curve and the Marine
curve is calculated. It is based upon an estimate of the percent marine
carbon in the sample.