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Rippert, Nadine; Baumann, Karl-Heinz; Pätzold, Jürgen (2015): Stable isotope and Mg/Ca ratio of sediment core GeoB12610-2. doi:10.1594/PANGAEA.841927,
Supplement to: Rippert, N et al. (2015): Thermocline fluctuations in the western tropical Indian Ocean during the past 35 ka. Journal of Quaternary Science, 30(3), 201-210, doi:10.1002/jqs.2767

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Abstract:
To reconstruct the still poorly understood thermocline fluctuations in the western tropical Indian Ocean, a sediment core located off Tanzania (GeoB12610-2; 04°49.00'S, 39°25.42'E, 399?m water depth) covering the last 35 ka was analysed. Mg/Ca-derived temperatures from the planktonic foraminifera Globigerinoides ruber (white) and Neogloboquadrina dutertrei indicate that the last glacial was ~2.5 °C colder in the surface waters and ~3.5 °C colder in the thermocline compared with the present day. The depth of the thermocline and thus the stratification of the water column were shallower during glacial periods and deepened during the deglaciation and Holocene. The increased inflow of Southern Ocean Intermediate Waters via 'ocean tunnels' appears to cool the thermocline from below, leading to a similarity between the thermocline record of GeoB12610-2 with the Antarctic EDML temperature curve during the glacial. With rising sea level and the corresponding greater inflow of Red Sea Waters and Indonesian Intermediate Waters, the proportion of Southern Ocean Intermediate Water within the South Equatorial Current is reduced and, by Holocene time, the correlation to Antarctica is barely traceable. Comparison with the eastern Indian Ocean reveals that the thermocline depth reverses from the last glacial to present.
Coverage:
Latitude: -4.816667 * Longitude: 39.423667
Date/Time Start: 2008-02-11T16:42:00 * Date/Time End: 2008-02-11T16:42:00
Minimum DEPTH, sediment/rock: 0.02 m * Maximum DEPTH, sediment/rock: 3.30 m
Event(s):
GeoB12610-2 (M75/2_97-2) * Latitude: -4.816667 * Longitude: 39.423667 * Date/Time: 2008-02-11T16:42:00 * Elevation: -399.0 m * Recovery: 7.62 m * Location: Pemba Channel * Campaign: M75/2 * Basis: Meteor (1986) * Device: Gravity corer (Kiel type) (SL)
Parameter(s):
#NameShort NameUnitPrincipal InvestigatorMethodComment
1DEPTH, sediment/rockDepthmGeocode
2AGEAgeka BPGeocode
3Globigerinoides ruber sensu stricto, d18OG. ruber ss d18Oper mil PDBBaumann, Karl-HeinzMass spectrometer Finnigan MAT 251
4Globigerinoides ruber sensu stricto, Magnesium/Calcium ratioG. ruber ss Mg/Cammol/molBaumann, Karl-HeinzICP-OES, Inductively coupled plasma - optical emission spectrometry
5Sea surface temperature, annual meanSST (1-12)°CBaumann, Karl-HeinzCalculated from Mg/Ca ratios (Dekens et al. 2002)
6Sea surface temperature, annual mean, standard deviationSST (1-12) std dev±Baumann, Karl-HeinzCalculated from Mg/Ca ratios (Dekens et al. 2002)
7Neogloboquadrina dutertrei, d18ON. dutertrei d18Oper mil PDBBaumann, Karl-HeinzMass spectrometer Finnigan MAT 251
8Neogloboquadrina dutertrei, Magnesium/Calcium ratioN. dutertrei Mg/Cammol/molBaumann, Karl-HeinzICP-OES, Inductively coupled plasma - optical emission spectrometry
9Thermocline temperatureTT°CBaumann, Karl-HeinzCalculated from Mg/Ca ratios (Anand et al., 2003)
10Thermocline temperature, standard deviationTT std dev±Baumann, Karl-HeinzCalculated from Mg/Ca ratios (Anand et al., 2003)
Size:
1258 data points

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