GISP2 14-C (radiocarbon) Measurements (Table 2).

REFERENCE:

Lal, D., A.J.T. Jull, G.S. Burr, and D.J. Donahue. 1997. Measurements of in
situ 14C concentrations in Greenland Ice Sheet Project 2 ice covering a 17
kyr time span: Implications to ice flow dynamics. Journal of Geophysical
Research 102:26505-26510.

DATA DESCRIPTION:

This file contains the data in Table 2 (calculated in-situ 14C
concentrations) from Lal and Jull (1997). 

Expected in-situ 14C is based on 14C production rate at surface for the
present altitude (3.2 km), 200 atoms 14C/g ice/y (Jull et al., 1994), and
model ice accumulation rates estimated by Cutler et al. (1995).  The
estimates are for in-situ cosmogenic 14C (i.e. excluding trapped 14C). 

For total - trapped CO2, the amount of trapped 14CO2 is estimated from
the amount of air in the ice (see Table 1) and assuming 250 ppm CO2 in
air.

Depth: Mean sample depth in meters.
Age: Age of ice in years.
Total: Decay-corrected 14C (atoms/g).
In situ produced: Decay-corrected 14C (atoms/g).
Total-Trapped CO2:  thickness model for Expected in-situ 14C.
Constant Variable:  thickness model for Expected in-situ 14C.

DATA:								

depth	age	Total	+/-	In situ	+/-	Total-trapped CO2	Constant 	Variable
							
88	225	1440	90	910	90	1370	1380	
100.7	275	1190	80	670	90	1370	1380	
101.1	275	2190	90	1370	100	1370	1380	
125.8	375	2070	80	1460	90	1370	1380	
126.2	375	1960	100	1350	120	1370	1380	
1518.5	9470	5720	250	5130	270	1540	1700	
1623.4	10770	3480	270	2870	300	1820	2110	
1698.5	12390	3580	350	2960	400	4380	5230
1749.4	13750	4180	450	3510	500	2330	2810
1837.4	16200	6295	650	5660	600	3965	4985