In:
Quaternary Research, Cambridge University Press (CUP), Vol. 86, No. 2 ( 2016-09), p. 162-169
Abstract:
We reconstruct centennial scale quantitative changes in surface seawater temperature (SST), evaporation-precipitation (from Mg/Ca and δ 18 O of surface dwelling planktic foraminifera), productivity (from relative abundance of Globigerina bulloides ), carbon burial (from %CaCO 3 and organic carbon [%C org ]) and dissolved oxygen at sediment-water interface, covering the entire Holocene, from a core collected from the eastern Arabian Sea. From the multi-proxy record, we define the timing, consequences and possible causes of the mid-Holocene climate transition (MHCT). A distinct shift in evaporation-precipitation (E-P) is observed at 6.4 ka, accompanied by a net cooling of SST. The shift in SST and E-P is synchronous with a change in surface productivity. A concurrent decrease is also noted in both the planktic foraminiferal abundance and coarse sediment fraction. A shift in carbon burial, as inferred from both the %CaCO 3 and %C org , coincides with a change in surface productivity. A simultaneous decrease in dissolved oxygen at the sediment-water interface, suggests that changes affected both the surface and subsurface water. A similar concomitant change is also observed in other cores from the Arabian Sea as well as terrestrial records, suggesting a widespread regional MHCT. The MHCT coincides with decreasing low-latitude summer insolation, perturbations in total solar intensity and an increase in atmospheric CO 2 .
Type of Medium:
Online Resource
ISSN:
0033-5894
,
1096-0287
DOI:
10.1016/j.yqres.2016.06.001
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
2016
detail.hit.zdb_id:
1471589-2
detail.hit.zdb_id:
205711-6
SSG:
13
SSG:
14
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