Details

Autor(en) / Beteiligte

• Auderset, Alexandra
• Martínez-García, Alfredo
• Tiedemann, Ralf
• Hasenfratz, Adam P.
• Eglinton, Timothy I.
• Schiebel, Ralf
• Sigman, Daniel M.
• Haug, Gerald H.

Titel

Gulf Stream intensification after the early Pliocene shoaling of the Central American Seaway

Ist Teil von

• Earth and planetary science letters, 2019-08, Vol.520, p.268-278

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2019

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• The shoaling of the Central American Seaway (CAS) around 4.6 Ma (million years ago) is thought to have enhanced the Gulf Stream, strengthening the Atlantic Meridional Overturning Circulation and potentially influencing the evolution of Pliocene climate. Paleoclimate records indicate a buildup of heat and salt in the Caribbean and changes in the formation of North Atlantic Deep Water (NADW) associated with a major step in the shoaling of the CAS at 4.6 Ma. However, so far, direct evidence supporting an intensification of the Gulf Stream is scarce. Here we report new North Atlantic early Pliocene (5.3–3.9 Ma) records of sea surface temperature (SST) reconstructed using the U37K' and TEX86 paleotemperature indices. Based on new sediment trap measurements near the study site, we suggest that in this particular region, the two paleothermometers record SST during different seasons: spring for UK37' and summer for TEX86. At 4.6 and 4.2 Ma, our results indicate substantial increases in SST and salinity during summer but not spring, pointing to a significant intensification of the Gulf Stream and its extension, the North Atlantic Current, after the shoaling of the CAS. The divergence of the U37K' and TEX86 temperature trends in those intervals suggests that the Gulf Stream intensification contributed to the strong North Atlantic seasonality that is observed today. •NA sediment traps suggest different seasons of production for alkenones and GDGTs.•DSDP Site 609 U37K' and TEX86H temperature trends diverge after 4.6 Ma.•Temperatures trends support Gulf Stream intensification after 4.6 Ma.•Gulf Stream intensification linked to formation of the Panama Isthmus.•4.6 Ma marks the onset of the strong North Atlantic seasonality observed today.