Faunal analysis and Mg/Ca records of planktic foraminifera in sediment core SO189/2_039KL


Autoria(s): Kwiatkowski, Cornelia; Prange, Matthias; Varma, Vidya; Steinke, Stephan; Hebbeln, Dierk; Mohtadi, Mahyar
Cobertura

LATITUDE: -0.790000 * LONGITUDE: 99.908500 * DATE/TIME START: 2006-09-14T06:40:00 * DATE/TIME END: 2006-09-14T06:40:00

Data(s)

23/04/2015

Resumo

Climate phenomena like the monsoon system, El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) are interconnected via various feedback mechanisms and control the climate of the Indian Ocean and its surrounding continents on various timescales. The eastern tropical Indian Ocean is a key area for the interplay of these phenomena and for reconstructing their past changes and forcing mechanisms. Here we present records of upper ocean thermal gradient, thermocline temperatures (TT) and relative abundances of planktic foraminifera in core SO 189-39KL taken off western Sumatra (0°47.400' S, 99°54.510' E) for the last 8 ka that we use as proxies for changes in upper ocean structure. The records suggest a deeper thermocline between 8 ka and ca 3 ka compared to the late Holocene. We find a shoaling of the thermocline after 3 ka, most likely indicating an increased occurrence of upwelling during the late Holocene compared to the mid-Holocene which might represent changes in the IOD-like mean state of the Indian Ocean with a more negative IOD-like mean state during the mid-Holocene and a more positive IOD-like mean state during the past 3 ka. This interpretation is supported by a transient Holocene climate model simulation in which an IOD-like mode is identified that involves an insolation-forced long-term trend of increasing anomalous surface easterlies over the equatorial eastern Indian Ocean.

Formato

application/zip, 2 datasets

Identificador

https://doi.pangaea.de/10.1594/PANGAEA.845549

doi:10.1594/PANGAEA.845549

Idioma(s)

en

Publicador

PANGAEA

Direitos

CC-BY: Creative Commons Attribution 3.0 Unported

Access constraints: unrestricted

Fonte

Supplement to: Kwiatkowski, Cornelia; Prange, Matthias; Varma, Vidya; Steinke, Stephan; Hebbeln, Dierk; Mohtadi, Mahyar (2015): Holocene variations of thermocline conditions in the eastern tropical Indian Ocean. Quaternary Science Reviews, 114, 33-42, doi:10.1016/j.quascirev.2015.01.028

Palavras-Chave #Age; AGE; Calculated using error propagation; Center for Marine Environmental Sciences; d18O cal; delta 18O, calcite; Depth; DEPTH, sediment/rock; Foram; Foraminifera; ICP-OES (Agilent 700 with autosampler ASX-520); MARUM; P. obliqu. Mg/Ca; Pulleniatina obliquiloculata, Magnesium/Calcium ratio; seawater; symbiont-barren species; symbiont-bearing species; Thermocline temperature; Thermocline temperature, standard deviation; TT; TT std dev
Tipo

Dataset