Data Formats for the Greenland Summit Ice Cores CD-ROM

All data files related to the ice cores on this CD-ROM are in a consistent 
format. The name of the data file and it's directory name can help you 
decipher what the data file is.  For example, the data file detiond.dat is in 
the directory "data/gisp2/chem".. This file refers to the GISP2 ions from 
the deep "D" ice core.  The exception to this format are the files related to 
atmospheric variables (directories "climate" and "traject") which have their 
own format. Please refer to the data file description associated with each 
of these data sets.

When reading the data file one will first see the title (eg. "GISP2 
Ions: Deep ("D") Core (Detailed)").  Next there will be a reference 
list, a detailed data description, and finally data values.  All data 
values will have an associated depth and age and are consistent across 
the entire data collection.  An example is given below.

NOTE: The data record has been truncated for use in the example only.  
Please refer to the data file on this CD-ROM to acquire the entire data 
record.


                             FORMAT EXAMPLE 

Data file uw2md18o.dat in the directory "data/gisp/isotopes"

***********
GISP2 Oxygen Isotope Data

REFERENCES:

Grootes, P.M., Stuiver, M., White, J.W.C., Johnsen, S., and Jouzel,
J.  1993.  Comparison of oxygen isotope records from the GISP2 and GRIP
Greenland ice cores. Nature.  366:552-554.

Stuiver, M., Grootes, P.M., and Braziunas, T.F.  1995.  The GISP2 delta 18O
climate record of the past 16,500 years and the role of the sun, ocean,
and volcanoes. Quaternary Research.  44:341-354.

DATA DESCRIPTION:

This file contains the GISP2 delta 18O vs. depth as well as age (2m
intervals).  The ages are interpolated from annual layer counts to 2431 m
(50 ka), from a correlated age model based on the delta 18O atm records
from GISPII and Vostok for 2482-2808 m (55.6 ka-111 ka), and from a
weighted average of the two age estimate methods for 2431-2482 m 
(50-55.6 ka) with a 100% weighting on the Meese estimate at 50 ka and 
100% on the Sowers estimate at 55.6 ka (references above).  Depth refers 
to the TOP depth of each delta 18O sample.  Unless there is a missing sample
specified below, these are continuous samples (e.g. sample #1 is a 2 m
delta 18O average covering 4 m to 6 m).  Standard deviation of the delta
18O measurements (sample equilibration plus mass spec determination) is
0.14 o/oo and the file delta 18O values have been corrected for minor
enrichment during storage (Stuiver et al. reference).

All ages are in kyr B.P. (A.D. 1950 = 0 yr B.P.).

DATA:

DEPTH   d18O    AGE
TOP     per mil kyr BP
4.0     -35.24  -0.034
6.0     -36.10  -0.030
8.0     -34.44  -0.026
10.0    -35.03  -0.022
12.0    -34.37  -0.017
14.0    -33.76  -0.012
16.0    -35.08  -0.008
18.0    -34.76  -0.003
20.0    -34.72  0.002
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