Citation:

G35806.1

Always quote citation above when using data! You can download the citation in several formats below.

RIS Citation BibTeX Citation Text Citation Facebook TwitterShow Map Google Earth

Abstract:

Biological productivity and carbon export in the equatorial Atlantic are thought to have been dramatically higher during the last glacial period than during the Holocene. Here we reconstruct the pH and CO2 content of surface waters from the eastern equatorial Atlantic Ocean over the past ~30 k.y. using the boron isotope composition of Globigerinoides ruber (a mixed-layer-dwelling planktic foraminifera). Our new record, combined with previously published data, indicates that during the last glacial, in contrast to today, a strong west to east gradient existed in the extent of air:sea equilibrium with respect to pCO2 (DeltapCO2), with the eastern equatorial Atlantic acting as a significant source of CO2 (+100 µatm) while the western Atlantic remained close to equilibrium (+25 µatm). This pattern suggests that a fivefold increase in the upwelling rate of deeper waters drove increased Atlantic productivity and large-scale regional cooling during the last glacial, but the higher than modern DeltapCO2 in the east indicates that export production did not keep up with enhanced upwelling of nutrients. However, the downstream decline of DeltapCO2 provides evidence that the unused nutrients from the east were eventually used for biologic carbon export, thereby effectively negating the impact of changes in upwelling on atmospheric CO2 levels. Our findings indicate that the equatorial Atlantic exerted a minimal role in contributing to lower glacial-age atmospheric CO2.

Source:

GSA data repository - 2014351 - Table DR1: Summary of boron isotope and Mg/Ca data

Project(s):

Geosciences, University of Bremen (GeoB)

Ocean Drilling Program (ODP)

Coverage:

Median Latitude: 4.970222 * Median Longitude: -44.263099 * South-bound Latitude: -1.665000 * West-bound Longitude: -78.739300 * North-bound Latitude: 12.744000 * East-bound Longitude: -12.428330

Date/Time Start: 1989-02-25T00:00:00 * Date/Time End: 1996-01-14T23:15:00

Minimum DEPTH, sediment/rock: 0.05 m * Maximum DEPTH, sediment/rock: 1.67 m

Event(s):

165-999A * Latitude: 12.744000 * Longitude: -78.739300 * Date/Time Start: 1996-01-10T19:30:00 * Date/Time End: 1996-01-14T23:15:00 * Elevation: -2828.0 m * Penetration: 566.1 m * Recovery: 534.83 m * Location: Caribbean Sea * Campaign: * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 61 core; 566.1 m cored; 0 m drilled; 94.5 % recovery

GeoB1105-4 * Latitude: -1.665000 * Longitude: -12.428330 * Date/Time: 1989-02-25T00:00:00 * Elevation: -3225.0 m * Penetration: 17 m * Recovery: 15.22 m * Location: Equatorial Atlantic * Campaign: * Basis: * Method/Device: Gravity corer (Kiel type) (SL) * Comment: cc: Karbonatschlamm, tonig

GeoB1523-1 * Latitude: 3.831667 * Longitude: -41.621667 * Date/Time: 1991-05-17T00:00:00 * Elevation: -3292.0 m * Recovery: 6.65 m * Location: Amazon Fan * Campaign: * Basis: * Method/Device: Gravity corer (Kiel type) (SL)

Parameter(s):

#	Name	Short Name	Unit	Principal Investigator	Method/Device	Comment
1	Event label	Event
2	DEPTH, sediment/rock	Depth sed	m			Geocode
3	AGE	Age	ka BP			Geocode
4	δ11B	δ11B	‰ SRM	Foster, Gavin L	MC-ICP-MS Thermo-Finnigan Neptune
5	δ11B, standard deviation	δ11B std dev	±	Foster, Gavin L
6	Globigerinoides ruber, Magnesium/Calcium ratio	G. ruber Mg/Ca	mmol/mol	Foster, Gavin L	ICP-MS, Thermo Fisher Scientific, Element 2
7	Sea surface temperature, annual mean	SST (1-12)	°C	Foster, Gavin L	Calculated from Mg/Ca ratios (Anand et al., 2003)
8	Carbon dioxide (water) partial pressure	pCO2(aq)	µatm	Foster, Gavin L		seawater
9	Carbon dioxide (water) partial pressure	pCO2(aq)	µatm	Foster, Gavin L		seawater, 2.5%
10	Carbon dioxide (water) partial pressure	pCO2(aq)	µatm	Foster, Gavin L		seawater, 14%
11	Carbon dioxide (water) partial pressure	pCO2(aq)	µatm	Foster, Gavin L		seawater, 86%
12	Carbon dioxide (water) partial pressure	pCO2(aq)	µatm	Foster, Gavin L		seawater, 97.5%

License:

Creative Commons Attribution 3.0 Unported (CC-BY-3.0)

Size:

423 data points

Data

Download dataset as tab-delimited text — use the following character encoding:

1 Event	2 Depth sed [m]	3 Age [ka BP]	4 δ11B [‰ SRM] (MC-ICP-MS Thermo-Finnigan Nep...)	5 δ11B std dev [±]	6 G. ruber Mg/Ca [mmol/mol] (ICP-MS, Thermo Fisher Scienti...)	7 SST (1-12) [°C] (Calculated from Mg/Ca ratios ...)	8 pCO2(aq) [µatm] (seawater)	9 pCO2(aq) [µatm] (seawater, 2.5%)	10 pCO2(aq) [µatm] (seawater, 14%)	11 pCO2(aq) [µatm] (seawater, 86%)	12 pCO2(aq) [µatm] (seawater, 97.5%)
GeoB1105-4	0.36	9.2	20.34	0.25	3.81	25.6	300	273	285	319	331
GeoB1105-4	0.46	11.4	20.65	0.25	4.03	26.2	270	251	256	285	290
GeoB1105-4	0.55	13.3	20.58	0.25	3.77	25.5	277	257	262	289	300
GeoB1105-4	0.65	14.6	20.72	0.25	3.54	24.8	256	229	244	273	278
GeoB1105-4	0.75	15.7	20.54	0.25	3.26	23.9	266	238	254	281	292
GeoB1105-4	0.80	16.4	20.13	0.25	2.86	22.4	302	277	287	316	324
GeoB1105-4	0.89	18.0	20.12	0.25	2.66	21.6	295	273	280	310	330
GeoB1105-4	0.95	19.1	20.21	0.25	2.81	22.2	290	261	272	309	334
GeoB1105-4	1.05	20.4	20.22	0.25	2.75	22.0	284	262	271	300	316
GeoB1105-4	1.15	21.5	19.86	0.25	2.69	21.7	330	301	310	348	367
GeoB1105-4	1.24	23.0	20.16	0.25	2.88	22.5	296	263	282	314	328
GeoB1105-4	1.37	24.8	20.35	0.25	2.94	22.7	281	249	266	295	309
GeoB1105-4	1.47	26.8	20.70	0.25	2.95	22.8	238	218	225	252	269
GeoB1105-4	1.57	28.8	20.14	0.25	2.96	22.8	303	270	286	319	331
GeoB1105-4	1.57	28.8	20.59	0.25	3.01	23.0	254	225	239	269	275
GeoB1105-4	1.67	30.8	20.73	0.25	3.03	23.1	244	218	230	258	268
GeoB1523-1	0.05	3.1	20.78	0.25	4.65	27.8	273	251	259	285	299
GeoB1523-1	0.10	6.0	20.72	0.25	4.47	27.4	277	253	265	294	300
GeoB1523-1	0.15	8.5	20.97	0.25	4.56	27.6	252	234	239	265	279
GeoB1523-1	0.20	10.5	20.73	0.25	4.29	26.9	273	245	258	287	300
GeoB1523-1	0.25	12.6	21.29	0.25	4.14	26.5	217	197	203	228	234
GeoB1523-1	0.30	14.6	21.13	0.25	4.02	26.2	229	210	218	239	258
GeoB1523-1	0.35	16.6	21.33	0.25	3.56	24.9	201	183	191	210	221
GeoB1523-1	0.40	18.2	21.37	0.25	3.68	25.2	203	181	191	214	219
GeoB1523-1	0.45	19.1	21.15	0.25	3.53	24.8	216	197	205	226	234
GeoB1523-1	0.55	20.9	21.14	0.25	3.81	25.6	222	206	212	232	242
GeoB1523-1	0.65	23.9	20.99	0.25	3.69	25.3	235	217	222	246	254
GeoB1523-1	0.75	27.4	21.17	0.25	3.69	25.2	219	200	208	229	240
GeoB1523-1	0.85	30.9	20.67	0.25	3.58	24.9	265	242	249	279	294
165-999A	0.05	3.9	20.67	0.25	4.80	28.2	288	268	273	303	310
165-999A	0.11	4.6	20.78	0.25	4.91	28.4	278	249	261	295	309
165-999A	0.15	5.0	20.59	0.25	4.76	28.1	299	268	283	319	332
165-999A	0.31	7.8	20.82	0.25	4.81	28.2	275	249	260	292	300
165-999A	0.31	7.8	20.72	0.25	4.81	28.2	279	254	265	294	310
165-999A	0.39	9.5	20.68	0.25	4.54	27.6	279	250	263	295	303
165-999A	0.43	10.3	20.93	0.25	4.51	27.5	256	230	240	269	282
165-999A	0.48	11.7	20.72	0.25	4.33	27.0	271	247	258	283	296
165-999A	0.57	14.0	20.98	0.25	4.48	27.4	251	229	237	264	270
165-999A	0.61	15.1	21.02	0.25	4.48	27.4	244	224	231	259	268
165-999A	0.61	15.1	21.15	0.25	4.48	27.4	233	213	224	242	248
165-999A	0.71	17.3	21.04	0.25	4.20	26.7	237	217	224	248	262
165-999A	0.82	19.2	21.75	0.25	4.03	26.2	183	168	174	191	200
165-999A	0.93	21.1	21.20	0.25	3.90	25.9	220	206	209	230	240
165-999A	1.02	22.5	21.26	0.25	4.21	26.7	220	203	207	231	239
165-999A	1.13	24.8	21.51	0.25	4.09	26.4	199	182	192	208	223
165-999A	1.20	26.3	21.62	0.25	4.04	26.3	191	173	181	201	209
165-999A	1.20	26.3	21.69	0.25	4.04	26.3	185	170	175	195	205