# Northeast Greenland Ice Stream (NEGIS) 2012 Ice Core Chemistry and Density
#----------------------------------------------------------------------- 
#                World Data Service for Paleoclimatology, Boulder 
#                                  and 
#                     NOAA Paleoclimatology Program 
#             National Centers for Environmental Information (NCEI)
#----------------------------------------------------------------------- 
# Template Version 2.0
# NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. 
# If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. 
#
# Online_Resource: https://www.ncdc.noaa.gov/paleo/study/20427  
# Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/negis2012age.txt
#
# Original_Source_URL: 
# 
# Description/Documentation lines begin with #
# Data lines have no #
#
# Archive: Ice Cores
#
# Parameter_Keywords: chemistry, physical properties, accumulation 
#--------------------
# Contribution_Date
#	Date: 2016-08-11 
#--------------------
# Title
#	Study_Name: Northeast Greenland Ice Stream (NEGIS) 2012 Ice Core Chemistry and Density
#--------------------
# Investigators
# 	Investigators: Vallelonga, P.
#--------------------
# Description_and_Notes
#	Description: CFA chemistry, density, accumulation, and annual layer thickness data produced from NEGIS 2012 ice core. 
#	Provided Keywords: ice core, accumulation, density, annual layer, ammonium, conductivity, Greenland, volcanoes, sea salt, sodium, dust, ice stream 
#--------------------
# Publication 
#	Authors: P. Vallelonga, K. Christianson, R.B. Alley, S. Anandakrishnan, J.E.M. Christian, D. Dahl-Jensen, V. Gkinis, C. Holme, R.W. Jacobel, N.B. Karlsson, B.A. Keisling, S. Kipfstuhl, H.A. Kjær, M.E.L. Kristensen, A. Muto, L.E. Peters, T. Popp, K.L. Riverman, A.M. Svensson, C. Tibuleac, B.M. Vinther, Y. Weng, and M. Winstrup 
#	Published_Date_or_Year: 2014-07-22
#	Published_Title: Initial results from geophysical surveys and shallow coring of the Northeast Greenland Ice Stream (NEGIS)
#	Journal_Name: The Cryosphere
#	Volume: 8
#	Edition: 
#	Issue: 4
#	Pages: 1275-1287
#	Report_Number: 
#	DOI: 10.5194/tc-8-1275-2014
#	Online_Resource: http://www.the-cryosphere.net/8/1275/2014/
#	Full_Citation: 
#	Abstract: The Northeast Greenland Ice Stream (NEGIS) is the sole interior Greenlandic ice stream. Fast flow initiates near the summit dome, and the ice stream terminates approximately 1000 km downstream in three large outlet glaciers that calve into the Greenland Sea. To better understand this important system, in the summer of 2012 we drilled a 67 m firn core and conducted ground-based radio-echo sounding (RES) and active-source seismic surveys at a site approximately 150 km downstream from the onset of streaming flow (NEGIS firn core, 75 37.61'N, 35 56.49'W). The site is representative of the upper part of the ice stream, while also being in a crevasse-free area for safe surface operations.

Annual cycles were observed for insoluble dust, sodium and ammonium concentrations and for electrolytic conductivity, allowing a seasonally resolved chronology covering the past 400 yr. Annual layer thicknesses averaged 0.11 m ice equivalent (i.e.) for the period 1607-2011, although accumulation varied between 0.08 and 0.14 m i.e., likely due to flow-related changes in surface topography. Tracing of RES layers from the NGRIP (North Greenland Ice Core Project) ice core site shows that the ice at NEGIS preserves a climatic record of at least the past 51 kyr. We demonstrate that deep ice core drilling in this location can provide a reliable Holocene and late-glacial climate record, as well as helping to constrain the past dynamics and ice-lithosphere interactions of the Greenland Ice Sheet.
#------------------
# Funding_Agency 
#	Funding_Agency_Name: Danish National Research Foundation 
#	Grant: Centre for Ice and Climate 
#------------------
# Funding_Agency 
#	Funding_Agency_Name: US National Science Foundation
#	Grant: OPP 0424589
#------------------
# Funding_Agency 
#	Funding_Agency_Name: US NASA Operation IceBridge
#	Grant: NNX13AD53A
#------------------
# Site_Information 
#	Site_Name: Northeast Greenland Ice Stream (NEGIS) 
#	Location: North America>Greenland 
#	Country: 
#	Northernmost_Latitude: 75.623
#	Southernmost_Latitude: 75.623
#	Easternmost_Longitude: -35.96
#	Westernmost_Longitude: -35.96
#	Elevation: 2702 m  
#------------------
# Data_Collection   
#	Collection_Name: NEGIS2012age
#	Earliest_Year: 343
#	Most_Recent_Year: -62
#	Time_Unit: Cal. year BP
#	Core_Length: 66.55 m
#	Notes: 
#------------------
# Chronology_Information
#	Chronology: Chronology established by annual layer counting with volcano tiepoints, as described in the reference. 
#	See full age model in file negis2012age.txt 
# 	
#----------------
# Variables 
#
# Data variables follow are preceded by "##" in columns one and two.
# Data line variables format:  Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) 
#
## depth_m	depth, , , m, , , , ,N
## thick_m	Annual Layer Thickness, ice, , m, , ice cores, , ,N 
## age_AD	age, , , AD, , , , ,N
## age_calBP	age, , , calendar years before present, , , , ,N
#
#----------------
# Data:
# Data lines follow (have no #)
# Data line format - tab-delimited text, variable short name as header
# Missing Values:  
#
depth_m	thick_m	age_AD	age_calBP
0.259		2012	-62
0.795	0.536	2011	-61
1.35	0.555	2010	-60
1.772	0.422	2009	-59
2.11	0.338	2008	-58
2.474	0.364	2007	-57
2.895	0.421	2006	-56
3.259	0.364	2005	-55
3.7	0.441	2004	-54
3.987	0.287	2003	-53
4.31	0.323	2002	-52
4.67	0.36	2001	-51
4.994	0.324	2000	-50
5.396	0.402	1999	-49
5.746	0.35	1998	-48
6.08	0.334	1997	-47
6.47	0.39	1996	-46
6.89	0.42	1995	-45
7.18	0.29	1994	-44
7.48	0.3	1993	-43
7.76	0.28	1992	-42
8.01	0.25	1991	-41
8.27	0.26	1990	-40
8.49	0.22	1989	-39
8.78	0.29	1988	-38
9.06	0.28	1987	-37
9.295	0.235	1986	-36
9.59	0.295	1985	-35
9.878	0.288	1984	-34
10.179	0.301	1983	-33
10.41	0.231	1982	-32
10.653	0.243	1981	-31
10.884	0.231	1980	-30
11.11	0.226	1979	-29
11.326	0.216	1978	-28
11.53	0.204	1977	-27
11.72	0.19	1976	-26
11.91	0.19	1975	-25
12.161	0.251	1974	-24
12.421	0.26	1973	-23
12.685	0.264	1972	-22
12.887	0.202	1971	-21
13.07	0.183	1970	-20
13.238	0.168	1969	-19
13.44	0.202	1968	-18
13.6	0.16	1967	-17
13.776	0.176	1966	-16
13.978	0.202	1965	-15
14.175	0.197	1964	-14
14.33	0.155	1963	-13
14.53	0.2	1962	-12
14.8	0.27	1961	-11
14.98	0.18	1960	-10
15.18	0.2	1959	-9
15.37	0.19	1958	-8
15.54	0.17	1957	-7
15.67	0.13	1956	-6
15.83	0.16	1955	-5
15.993	0.163	1954	-4
16.27	0.277	1953	-3
16.46	0.19	1952	-2
16.6	0.14	1951	-1
16.85	0.25	1950	0
17.04	0.19	1949	1
17.206	0.166	1948	2
17.37	0.164	1947	3
17.502	0.132	1946	4
17.62	0.118	1945	5
17.77	0.15	1944	6
17.887	0.117	1943	7
18.111	0.224	1942	8
18.303	0.192	1941	9
18.43	0.127	1940	10
18.62	0.19	1939	11
18.72	0.1	1938	12
18.86	0.14	1937	13
19.01	0.15	1936	14
19.162	0.152	1935	15
19.32	0.158	1934	16
19.45	0.13	1933	17
19.649	0.199	1932	18
19.806	0.157	1931	19
20.05	0.244	1930	20
20.245	0.195	1929	21
20.36	0.115	1928	22
20.49	0.13	1927	23
20.6	0.11	1926	24
20.774	0.174	1925	25
20.96	0.186	1924	26
21.08	0.12	1923	27
21.22	0.14	1922	28
21.36	0.14	1921	29
21.49	0.13	1920	30
21.68	0.19	1919	31
21.867	0.187	1918	32
22.005	0.138	1917	33
22.152	0.147	1916	34
22.293	0.141	1915	35
22.489	0.196	1914	36
22.727	0.238	1913	37
22.861	0.134	1912	38
23.06	0.199	1911	39
23.213	0.153	1910	40
23.367	0.154	1909	41
23.498	0.131	1908	42
23.63	0.132	1907	43
23.767	0.137	1906	44
23.983	0.216	1905	45
24.075	0.092	1904	46
24.213	0.138	1903	47
24.39	0.177	1902	48
24.56	0.17	1901	49
24.74	0.18	1900	50
24.9	0.16	1899	51
25.046	0.146	1898	52
25.264	0.218	1897	53
25.438	0.174	1896	54
25.675	0.237	1895	55
25.796	0.121	1894	56
25.963	0.167	1893	57
26.16	0.197	1892	58
26.29	0.13	1891	59
26.45	0.16	1890	60
26.61	0.16	1889	61
26.75	0.14	1888	62
26.97	0.22	1887	63
27.111	0.141	1886	64
27.25	0.139	1885	65
27.41	0.16	1884	66
27.534	0.124	1883	67
27.707	0.173	1882	68
27.867	0.16	1881	69
28.053	0.186	1880	70
28.229	0.176	1879	71
28.428	0.199	1878	72
28.623	0.195	1877	73
28.819	0.196	1876	74
28.995	0.176	1875	75
29.139	0.144	1874	76
29.287	0.148	1873	77
29.441	0.154	1872	78
29.582	0.141	1871	79
29.771	0.189	1870	80
29.915	0.144	1869	81
30.07	0.155	1868	82
30.31	0.24	1867	83
30.51	0.2	1866	84
30.71	0.2	1865	85
30.85	0.14	1864	86
31.034	0.184	1863	87
31.23	0.196	1862	88
31.354	0.124	1861	89
31.51	0.156	1860	90
31.726	0.216	1859	91
31.883	0.157	1858	92
32.037	0.154	1857	93
32.175	0.138	1856	94
32.319	0.144	1855	95
32.524	0.205	1854	96
32.713	0.189	1853	97
32.857	0.144	1852	98
33.063	0.206	1851	99
33.29	0.227	1850	100
33.402	0.112	1849	101
33.613	0.211	1848	102
33.753	0.14	1847	103
33.909	0.156	1846	104
34.127	0.218	1845	105
34.267	0.14	1844	106
34.452	0.185	1843	107
34.6	0.148	1842	108
34.74	0.14	1841	109
34.926	0.186	1840	110
35.08	0.154	1839	111
35.271	0.191	1838	112
35.469	0.198	1837	113
35.642	0.173	1836	114
35.834	0.192	1835	115
36.006	0.172	1834	116
36.169	0.163	1833	117
36.326	0.157	1832	118
36.548	0.222	1831	119
36.676	0.128	1830	120
36.839	0.163	1829	121
36.993	0.154	1828	122
37.243	0.25	1827	123
37.422	0.179	1826	124
37.553	0.131	1825	125
37.71	0.157	1824	126
37.896	0.186	1823	127
38.136	0.24	1822	128
38.261	0.125	1821	129
38.377	0.116	1820	130
38.566	0.189	1819	131
38.755	0.189	1818	132
38.886	0.131	1817	133
39.072	0.186	1816	134
39.229	0.157	1815	135
39.41	0.181	1814	136
39.524	0.114	1813	137
39.731	0.207	1812	138
39.937	0.206	1811	139
40.098	0.161	1810	140
40.223	0.125	1809	141
40.399	0.176	1808	142
40.565	0.166	1807	143
40.72	0.155	1806	144
40.874	0.154	1805	145
41.026	0.152	1804	146
41.193	0.167	1803	147
41.33	0.137	1802	148
41.536	0.206	1801	149
41.7	0.164	1800	150
41.884	0.184	1799	151
42.071	0.187	1798	152
42.19	0.119	1797	153
42.393	0.203	1796	154
42.55	0.157	1795	155
42.696	0.146	1794	156
42.857	0.161	1793	157
42.973	0.116	1792	158
43.16	0.187	1791	159
43.307	0.147	1790	160
43.414	0.107	1789	161
43.595	0.181	1788	162
43.767	0.172	1787	163
43.938	0.171	1786	164
44.048	0.11	1785	165
44.181	0.133	1784	166
44.36	0.179	1783	167
44.517	0.157	1782	168
44.631	0.114	1781	169
44.809	0.178	1780	170
44.96	0.151	1779	171
45.119	0.159	1778	172
45.249	0.13	1777	173
45.411	0.162	1776	174
45.551	0.14	1775	175
45.678	0.127	1774	176
45.844	0.166	1773	177
45.988	0.144	1772	178
46.11	0.122	1771	179
46.213	0.103	1770	180
46.31	0.097	1769	181
46.426	0.116	1768	182
46.533	0.107	1767	183
46.67	0.137	1766	184
46.834	0.164	1765	185
46.94	0.106	1764	186
47.08	0.14	1763	187
47.173	0.093	1762	188
47.273	0.1	1761	189
47.393	0.12	1760	190
47.499	0.106	1759	191
47.646	0.147	1758	192
47.752	0.106	1757	193
47.863	0.111	1756	194
47.991	0.128	1755	195
48.08	0.089	1754	196
48.247	0.167	1753	197
48.327	0.08	1752	198
48.452	0.125	1751	199
48.548	0.096	1750	200
48.667	0.119	1749	201
48.777	0.11	1748	202
48.911	0.134	1747	203
49.027	0.116	1746	204
49.167	0.14	1745	205
49.295	0.128	1744	206
49.426	0.131	1743	207
49.545	0.119	1742	208
49.706	0.161	1741	209
49.862	0.156	1740	210
50.003	0.141	1739	211
50.161	0.158	1738	212
50.249	0.088	1737	213
50.386	0.137	1736	214
50.53	0.144	1735	215
50.63	0.1	1734	216
50.786	0.156	1733	217
50.877	0.091	1732	218
51.021	0.144	1731	219
51.139	0.118	1730	220
51.265	0.126	1729	221
51.42	0.155	1728	222
51.545	0.125	1727	223
51.689	0.144	1726	224
51.795	0.106	1725	225
51.89	0.095	1724	226
51.973	0.083	1723	227
52.119	0.146	1722	228
52.238	0.119	1721	229
52.356	0.118	1720	230
52.481	0.125	1719	231
52.618	0.137	1718	232
52.722	0.104	1717	233
52.863	0.141	1716	234
52.981	0.118	1715	235
53.072	0.091	1714	236
53.2	0.128	1713	237
53.343	0.143	1712	238
53.512	0.169	1711	239
53.6	0.088	1710	240
53.711	0.111	1709	241
53.832	0.121	1708	242
53.926	0.094	1707	243
54.057	0.131	1706	244
54.161	0.104	1705	245
54.301	0.14	1704	246
54.414	0.113	1703	247
54.514	0.1	1702	248
54.636	0.122	1701	249
54.761	0.125	1700	250
54.917	0.156	1699	251
55.012	0.095	1698	252
55.137	0.125	1697	253
55.286	0.149	1696	254
55.42	0.134	1695	255
55.508	0.088	1694	256
55.613	0.105	1693	257
55.726	0.113	1692	258
55.863	0.137	1691	259
56.024	0.161	1690	260
56.139	0.115	1689	261
56.274	0.135	1688	262
56.39	0.116	1687	263
56.509	0.119	1686	264
56.673	0.164	1685	265
56.789	0.116	1684	266
56.899	0.11	1683	267
56.994	0.095	1682	268
57.161	0.167	1681	269
57.28	0.119	1680	270
57.384	0.104	1679	271
57.503	0.119	1678	272
57.634	0.131	1677	273
57.765	0.131	1676	274
57.893	0.128	1675	275
58.018	0.125	1674	276
58.155	0.137	1673	277
58.286	0.131	1672	278
58.378	0.092	1671	279
58.491	0.113	1670	280
58.615	0.124	1669	281
58.777	0.162	1668	282
58.866	0.089	1667	283
58.997	0.131	1666	284
59.075	0.078	1665	285
59.2	0.125	1664	286
59.326	0.126	1663	287
59.438	0.112	1662	288
59.551	0.113	1661	289
59.645	0.094	1660	290
59.78	0.135	1659	291
59.967	0.187	1658	292
60.109	0.142	1657	293
60.237	0.128	1656	294
60.368	0.131	1655	295
60.478	0.11	1654	296
60.576	0.098	1653	297
60.723	0.147	1652	298
60.88	0.157	1651	299
60.978	0.098	1650	300
61.094	0.116	1649	301
61.222	0.128	1648	302
61.341	0.119	1647	303
61.476	0.135	1646	304
61.584	0.108	1645	305
61.664	0.08	1644	306
61.78	0.116	1643	307
61.911	0.131	1642	308
62.018	0.107	1641	309
62.143	0.125	1640	310
62.259	0.116	1639	311
62.42	0.161	1638	312
62.56	0.14	1637	313
62.655	0.095	1636	314
62.765	0.11	1635	315
62.889	0.124	1634	316
63.029	0.14	1633	317
63.179	0.15	1632	318
63.289	0.11	1631	319
63.447	0.158	1630	320
63.564	0.117	1629	321
63.679	0.115	1628	322
63.82	0.141	1627	323
63.939	0.119	1626	324
64.095	0.156	1625	325
64.185	0.09	1624	326
64.308	0.123	1623	327
64.44	0.132	1622	328
64.53	0.09	1621	329
64.638	0.108	1620	330
64.757	0.119	1619	331
64.867	0.11	1618	332
64.977	0.11	1617	333
65.086	0.109	1616	334
65.232	0.146	1615	335
65.352	0.12	1614	336
65.452	0.1	1613	337
65.542	0.09	1612	338
65.654	0.112	1611	339
65.799	0.145	1610	340
65.91	0.111	1609	341
66.027	0.117	1608	342
66.149	0.122	1607	343