Glacial induced closure of the Panamanian Gateway during Marine Isotope Stages (MIS) 95–100 (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:mo>∼</mml:mo><mml:mn>2.5</mml:mn><mml:mtext> Ma</mml:mtext></mml:math>)

Groeneveld, Jeroen; Hathorne, Ed C; Steinke, Stephan; DeBey, Henry; Mackensen, Andreas; Tiedemann, Ralf

doi:10.1016/j.epsl.2014.08.007

Cited by 30 publications

(42 citation statements)

References 84 publications

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“…This observation is in line with previous modeling efforts ( Lee and Poulsen, 2005) and proxy-based (both geochemical and faunal) studies from EEP "cold tongue" ODP Sites 846 and 849 that cover the same time interval (Bolton et al, 2010;Jakob et al, 2017). However, it contradicts geochemical data (i.e., the surface to thermocline (Globigerinoides sacculifer to N. dutertrei) Mg / Ca-based temperature gradient) derived from Site 1241 located in the east Pacific "warm pool", which shows glacialinterglacial variations in thermocline depth for MIS 100-96 (Groeneveld et al, 2014) (Fig. 8).…”

Section: Mg / Ca-based Temperature Datamentioning

confidence: 68%

“…Therefore, we hypothesize that thermocline depth underwent a different evolution on the glacial-interglacial timescale in regions inside (Sites 846 and 849) and outside (Site 1241) the "cold tongue". Further, water column stratification and thermocline depth at Site 1241 has been shown to be affected by glacioeustatic closures of the Central American Seaway that temporally occurred during MIS 100-96 (Groeneveld et al, 2014), perhaps due to upwelling intensification (Schneider and Schmittner, 2006). In contrast, Site 849 appears to be unaffected by such changes, as shown by sand accumulation rate based data on export production (Jakob et al, 2016).…”

Section: Mg / Ca-based Temperature Datamentioning

confidence: 90%

“…1a, b and 6). In comparison to thermocline temperature records from Site 1241 (Steph et al, 2006a;Groeneveld et al, 2014) our new G. crassaformis-based temperatures appear to be relatively low. However, this discrepancy can likely be explained by different calcification depths of the investigated species (which means that different temperatures are reflected; Cléroux et al, 2013) and differences in the oceanographic setting of the investigated sites (i.e., Site 849 in the "cold tongue" versus Site 1241 in the "warm pool" with, for example, a modern-day SST difference of ∼ 3 • C; Locarnini et al, 2013; see also Sect.…”

Section: Mg / Ca-based Temperature Datamentioning

confidence: 99%

“…5d). Moreover, temporal closures of the Central American Seaway might have additionally promoted generally increasing upwelling and therefore primary productivity rates since MIS 100 (Schneider and Schmittner, 2006;Groeneveld et al, 2014).…”

Section: Faunal and Sedimentological Evidencementioning

confidence: 99%

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Thermocline state change in the eastern equatorial Pacific during the late Pliocene/early Pleistocene intensification of Northern Hemisphere glaciation

et al. 2018

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Abstract. The late Pliocene/early Pleistocene intensification of Northern Hemisphere glaciation (iNHG) ∼ 2.5 million years ago (marine isotope stages, MIS, 100-96) stands out as an important tipping point in Earth's climate history, which strongly influenced oceanographic and climatic patterns including trade wind and upwelling strength in the eastern equatorial Pacific (EEP). The thermocline depth in the EEP, in turn, plays a pivotal role in the Earth's climate system: small changes in its depth associated with short-term climate phenomena such as the El Niño-Southern Oscillation can affect surface-water properties and the ocean-atmosphere exchange. However, thermocline dynamics in the EEP during the iNHG still remain unclear. While numerous studies have suggested a link between a thermocline shoaling in the EEP and Northern Hemisphere ice growth, other studies have indicated a stable thermocline depth during the iNHG; consequently, a causal relationship between thermocline dynamics and ice-sheet growth has been excluded. In light of these contradictory views, we have generated geochemical (planktic foraminiferal δ 18 O, δ 13 C and Mg / Ca), sedimentological (sand accumulation rates) and faunal (abundance data of thermocline-dwelling foraminifera) records for Ocean Drilling Program Site 849 located in the central region of the EEP. Our records span the interval from ∼ 2.75 to 2.4 Ma (MIS G7-95), which is critical for understanding thermocline dynamics during the final phase of the iNHG. Our new records document a thermocline shoaling from ∼ 2.64 to 2.55 Ma (MIS G2-101) and a relatively shallow thermocline from ∼ 2.55 Ma onwards . This indicates a state change in thermocline depth at Site 849 shortly before the final phase of the iNHG. Ultimately, our data support the hypothesis that (sub-)tropical thermocline shoaling may have contributed to the development of large Northern Hemisphere ice sheets.

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Section: Mg / Ca-based Temperature Datamentioning

confidence: 68%

Section: Mg / Ca-based Temperature Datamentioning

confidence: 90%

Section: Mg / Ca-based Temperature Datamentioning

confidence: 99%

Section: Faunal and Sedimentological Evidencementioning

confidence: 99%

See 2 more Smart Citations

Thermocline state change in the eastern equatorial Pacific during the late Pliocene/early Pleistocene intensification of Northern Hemisphere glaciation

et al. 2018

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“…3.312-3.264 Ma (MIS M2; e.g., Lisiecki and Raymo, 2005;Khélifi et al, 2009;McKay et al, 2012) or the Early Pleis to cene one at ca. 2.5 Ma (MIS 95-100; Groeneveld et al, 2014). At that time, the wa ter level of the world's ocean de creased by even 65 m (Dwyer and Chan dler, 2009;Miller et 248 £ukasz Bujak et al Dolan et al, 2015), which re sulted in a sig nif i cant reduc tion of the base level of ero sion.…”

Section: Discussion the Age Of Sedimentmentioning

confidence: 99%

A new stratigraphic position of some Early Pleistocene deposits in central Poland

Bujak

Woronko

Winter

et al. 2015

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Plio‐Pleistocene glacial‐interglacial productivity changes in the eastern equatorial Pacific upwelling system

et al. 2016

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The eastern equatorial Pacific Ocean (EEP) upwelling system supports >10% of the present-day global ocean primary production, making it an important component in Earth's atmospheric and marine carbon budget. Traditionally, it has been argued that since intensification of Northern Hemisphere glaciation (iNHG,~2.7 Ma), changes in EEP productivity have predominantly depended on trade wind strength-controlled upwelling intensity. An alternative hypothesis suggests that EEP productivity is primarily controlled by nutrient supply from the high southern latitudes via mode waters. Here we present new high-resolution data for the latest Pliocene/early Pleistocene from Ocean Drilling Program Site 849, located within the equatorial divergence system in the heart of the EEP upwelling regime. We use carbon isotopes in benthic and planktic foraminiferal calcite and sand accumulation rates to investigate glacial-interglacial (G-IG) productivity fluctuations between 2.65 and 2.4 Ma (marine isotope stages (MIS) G1 to 94). This interval includes MIS 100, 98, and 96, three large-amplitude glacials (~1‰ in benthic δ 18 O) representing the culmination of iNHG. Our results suggest that latest Pliocene/early Pleistocene G-IG productivity changes in the EEP were strongly controlled by nutrient supply from Southern Ocean-sourced mode waters. Our records show a clear G-IG cyclicity from MIS 100 onward with productivity levels increasing from full glacial conditions and peaking at glacial terminations. We conclude that enhanced nutrient delivery from high southern latitudes during full glacial conditions together with superimposed intensified regional upwelling toward glacial terminations strongly regulated primary productivity rates in the EEP from MIS 100 onward.

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Glacial induced closure of the Panamanian Gateway during Marine Isotope Stages (MIS) 95–100 (∼2.5 Ma)

Cited by 30 publications

References 84 publications

Thermocline state change in the eastern equatorial Pacific during the late Pliocene/early Pleistocene intensification of Northern Hemisphere glaciation

Thermocline state change in the eastern equatorial Pacific during the late Pliocene/early Pleistocene intensification of Northern Hemisphere glaciation

A new stratigraphic position of some Early Pleistocene deposits in central Poland

Plio‐Pleistocene glacial‐interglacial productivity changes in the eastern equatorial Pacific upwelling system

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