Sea surface temperature reconstruction of ODP Site 175-1087


Autoria(s): McClymont, Erin L; Rosell-Melé, V; Giraudeau, Jaques; Pierre, Catherine; Lloyd, Jerry M
Cobertura

LATITUDE: -31.465083 * LONGITUDE: 15.310889 * DATE/TIME START: 1997-10-03T00:00:00 * DATE/TIME END: 1997-10-03T00:00:00

Data(s)

26/05/2005

Resumo

Successful application of the alkenone palaeothermometer, the UK'37 index, relies upon the assumption that fossil alkenone synthesisers responded to growth-temperature changes in a similar manner to the modern producers, chiefly the coccolithophores Emiliania huxleyi and Gephyrocapsa oceanica. We compare coccolith and UK'37 data from ODP Site 1087 in the south-east Atlantic between 1500 and 500 ka, and show that evolutionary events and changes in species dominance within the coccolithophore populations had little impact on the UK'37 record. The relative abundances of the C37 and C38 alkenones also closely resembled those found in modern populations, and suggest a similar temperature sensitivity of UK'37 during the early and mid-Pleistocene to that found at present. These results support the application of the UK'37 index to reconstruct sea-surface temperatures (SSTs) throughout the Quaternary. The UK'37 record at ODP Site 1087 contains an SST signal that documents the emergence of the 100-kyr cycles that characterise the late Quaternary ice volume records. This is preceded by significant cooling at ODP Site 1087, marked by a negative shift in SSTs and a positive shift in the planktonic delta18O some 250-kyr earlier, at ca 1150-1000 ka. This results in a permanent fall in average SSTs of around 1.5 °C. The predicted increase in aridity onshore as a result of this cooling can be identified in a number of published records from southern Africa, and may have played a role in some important evolutionary events of the mid-Pleistocene.

Formato

application/zip, 2 datasets

Identificador

https://doi.pangaea.de/10.1594/PANGAEA.738377

doi:10.1594/PANGAEA.738377

Idioma(s)

en

Publicador

PANGAEA

Direitos

CC-BY: Creative Commons Attribution 3.0 Unported

Access constraints: unrestricted

Fonte

Supplement to: McClymont, Erin L; Rosell-Melé, V; Giraudeau, Jaques; Pierre, Catherine; Lloyd, Jerry M (2005): Alkenone and coccolith records of the mid-Pleistocene in the south-east Atlantic: implications for the Uk37' index and South African climate. Quaternary Science Reviews, 24(14-15), 1559-1572, doi:10.1016/j.quascirev.2004.06.024

Palavras-Chave #175-1087; Age; AGE; Age model; Alkenone, unsaturation index UK'37; Benguela Current, South Atlantic Ocean; Calculated; COMPCORE; Composite Core; Depth; DEPTH, sediment/rock; Isotopic event; Joides Resolution; Label; Leg175; Ocean Drilling Program; ODP; ODP sample designation; Sample code/label; Sea surface temperature, annual mean; SST (1-12); UK'37
Tipo

Dataset