Skip to content

Research at St Andrews

Deciphering the state of the late Miocene to early Pliocene equatorial Pacific

Research output: Contribution to journalArticle

DOI

Open Access permissions

Open

Standard

Deciphering the state of the late Miocene to early Pliocene equatorial Pacific. / Drury, A. J.; Lee, G. P.; Gray, W. R.; Lyle, M.; Westerhold, T.; Shevenell, A. E.; John, C. M.

In: Paleoceanography and Paleoclimatology, Vol. Early View, 11.03.2018.

Research output: Contribution to journalArticle

Harvard

Drury, AJ, Lee, GP, Gray, WR, Lyle, M, Westerhold, T, Shevenell, AE & John, CM 2018, 'Deciphering the state of the late Miocene to early Pliocene equatorial Pacific' Paleoceanography and Paleoclimatology, vol. Early View. https://doi.org/10.1002/2017PA003245

APA

Drury, A. J., Lee, G. P., Gray, W. R., Lyle, M., Westerhold, T., Shevenell, A. E., & John, C. M. (2018). Deciphering the state of the late Miocene to early Pliocene equatorial Pacific. Paleoceanography and Paleoclimatology, Early View. https://doi.org/10.1002/2017PA003245

Vancouver

Drury AJ, Lee GP, Gray WR, Lyle M, Westerhold T, Shevenell AE et al. Deciphering the state of the late Miocene to early Pliocene equatorial Pacific. Paleoceanography and Paleoclimatology. 2018 Mar 11;Early View. https://doi.org/10.1002/2017PA003245

Author

Drury, A. J. ; Lee, G. P. ; Gray, W. R. ; Lyle, M. ; Westerhold, T. ; Shevenell, A. E. ; John, C. M. / Deciphering the state of the late Miocene to early Pliocene equatorial Pacific. In: Paleoceanography and Paleoclimatology. 2018 ; Vol. Early View.

Bibtex - Download

@article{d97e7c56056c40bab3ae854b9c33faed,
title = "Deciphering the state of the late Miocene to early Pliocene equatorial Pacific",
abstract = "The late Miocene-early Pliocene was a time of global cooling and the development of modern meridional thermal gradients. Equatorial Pacific sea surface conditions potentially played an important role in this global climate transition, but their evolution is poorly understood. Here, we present the first continuous late Miocene-early Pliocene (8.0-4.4 Ma) planktic foraminiferal stable isotope records from eastern equatorial Pacific Integrated Ocean Drilling Program Site U1338, with a new astrochronology spanning 8.0-3.5 Ma. Mg/Ca analyses on surface dwelling foraminifera Trilobatus sacculifer from carefully selected samples suggest mean sea-surface-temperatures (SSTs) are ~27.8±1.1°C (1σ) between 6.4-5.5 Ma. The planktic foraminiferal δ18O record implies a 2°C cooling between 7.2-6.1 Ma and an up to 3°C warming between 6.1-4.4 Ma, consistent with observed tropical alkenone paleo-SSTs. Diverging fine-fraction-to-foraminiferal δ13C gradients likely suggest increased upwelling from 7.1-6.0 and 5.8-4.6 Ma, concurrent with the globally recognized late Miocene Biogenic Bloom. This study shows that both warm and asymmetric mean states occurred in the equatorial Pacific during the late Miocene-early Pliocene. Between 8.0-6.5 and 5.2-4.4 Ma, low east-west δ18O and SST gradients and generally warm conditions prevailed. However, an asymmetric mean climate state developed between 6.5-5.7 Ma, with larger east-west δ18O and SST gradients and eastern equatorial Pacific cooling. The asymmetric mean state suggests stronger trade winds developed, driven by increased meridional thermal gradients associated with global cooling and declining atmospheric pCO2 concentrations. These oscillations in equatorial Pacific mean state are reinforced by Antarctic cryosphere expansion and related changes in oceanic gateways (e.g., Central American Seaway/Indonesian Throughflow restriction).",
keywords = "Planktic foraminifera stable isotope records, Late Miocene to early Pliocene, Equatorial Pacific mean state, Surface ocean conditions, Biogenic bloom, Mg/Ca sea surface temperature",
author = "Drury, {A. J.} and Lee, {G. P.} and Gray, {W. R.} and M. Lyle and T. Westerhold and Shevenell, {A. E.} and John, {C. M.}",
note = "A.J. Drury was funded by a Janet Watson studentship from Imperial College London.",
year = "2018",
month = "3",
day = "11",
doi = "10.1002/2017PA003245",
language = "English",
volume = "Early View",
journal = "Paleoceanography",
issn = "0883-8305",
publisher = "American Geophysical Union",

}

RIS (suitable for import to EndNote) - Download

TY - JOUR

T1 - Deciphering the state of the late Miocene to early Pliocene equatorial Pacific

AU - Drury, A. J.

AU - Lee, G. P.

AU - Gray, W. R.

AU - Lyle, M.

AU - Westerhold, T.

AU - Shevenell, A. E.

AU - John, C. M.

N1 - A.J. Drury was funded by a Janet Watson studentship from Imperial College London.

PY - 2018/3/11

Y1 - 2018/3/11

N2 - The late Miocene-early Pliocene was a time of global cooling and the development of modern meridional thermal gradients. Equatorial Pacific sea surface conditions potentially played an important role in this global climate transition, but their evolution is poorly understood. Here, we present the first continuous late Miocene-early Pliocene (8.0-4.4 Ma) planktic foraminiferal stable isotope records from eastern equatorial Pacific Integrated Ocean Drilling Program Site U1338, with a new astrochronology spanning 8.0-3.5 Ma. Mg/Ca analyses on surface dwelling foraminifera Trilobatus sacculifer from carefully selected samples suggest mean sea-surface-temperatures (SSTs) are ~27.8±1.1°C (1σ) between 6.4-5.5 Ma. The planktic foraminiferal δ18O record implies a 2°C cooling between 7.2-6.1 Ma and an up to 3°C warming between 6.1-4.4 Ma, consistent with observed tropical alkenone paleo-SSTs. Diverging fine-fraction-to-foraminiferal δ13C gradients likely suggest increased upwelling from 7.1-6.0 and 5.8-4.6 Ma, concurrent with the globally recognized late Miocene Biogenic Bloom. This study shows that both warm and asymmetric mean states occurred in the equatorial Pacific during the late Miocene-early Pliocene. Between 8.0-6.5 and 5.2-4.4 Ma, low east-west δ18O and SST gradients and generally warm conditions prevailed. However, an asymmetric mean climate state developed between 6.5-5.7 Ma, with larger east-west δ18O and SST gradients and eastern equatorial Pacific cooling. The asymmetric mean state suggests stronger trade winds developed, driven by increased meridional thermal gradients associated with global cooling and declining atmospheric pCO2 concentrations. These oscillations in equatorial Pacific mean state are reinforced by Antarctic cryosphere expansion and related changes in oceanic gateways (e.g., Central American Seaway/Indonesian Throughflow restriction).

AB - The late Miocene-early Pliocene was a time of global cooling and the development of modern meridional thermal gradients. Equatorial Pacific sea surface conditions potentially played an important role in this global climate transition, but their evolution is poorly understood. Here, we present the first continuous late Miocene-early Pliocene (8.0-4.4 Ma) planktic foraminiferal stable isotope records from eastern equatorial Pacific Integrated Ocean Drilling Program Site U1338, with a new astrochronology spanning 8.0-3.5 Ma. Mg/Ca analyses on surface dwelling foraminifera Trilobatus sacculifer from carefully selected samples suggest mean sea-surface-temperatures (SSTs) are ~27.8±1.1°C (1σ) between 6.4-5.5 Ma. The planktic foraminiferal δ18O record implies a 2°C cooling between 7.2-6.1 Ma and an up to 3°C warming between 6.1-4.4 Ma, consistent with observed tropical alkenone paleo-SSTs. Diverging fine-fraction-to-foraminiferal δ13C gradients likely suggest increased upwelling from 7.1-6.0 and 5.8-4.6 Ma, concurrent with the globally recognized late Miocene Biogenic Bloom. This study shows that both warm and asymmetric mean states occurred in the equatorial Pacific during the late Miocene-early Pliocene. Between 8.0-6.5 and 5.2-4.4 Ma, low east-west δ18O and SST gradients and generally warm conditions prevailed. However, an asymmetric mean climate state developed between 6.5-5.7 Ma, with larger east-west δ18O and SST gradients and eastern equatorial Pacific cooling. The asymmetric mean state suggests stronger trade winds developed, driven by increased meridional thermal gradients associated with global cooling and declining atmospheric pCO2 concentrations. These oscillations in equatorial Pacific mean state are reinforced by Antarctic cryosphere expansion and related changes in oceanic gateways (e.g., Central American Seaway/Indonesian Throughflow restriction).

KW - Planktic foraminifera stable isotope records

KW - Late Miocene to early Pliocene

KW - Equatorial Pacific mean state

KW - Surface ocean conditions

KW - Biogenic bloom

KW - Mg/Ca sea surface temperature

U2 - 10.1002/2017PA003245

DO - 10.1002/2017PA003245

M3 - Article

VL - Early View

JO - Paleoceanography

T2 - Paleoceanography

JF - Paleoceanography

SN - 0883-8305

ER -

Related by journal

  1. Improving North Atlantic marine core chronologies using 230Th-normalization

    Missiaen, L., Waelbroeck, C., Pichat, S., Jaccard, S. L., Eynaud, F., Greenop, R. & Burke, A., 10 Jul 2019, In : Paleoceanography and Paleoclimatology. 34, 17 p.

    Research output: Contribution to journalArticle

  2. Acceleration of northern ice sheet melt induces AMOC slowdown and northern cooling in simulations of the early last deglaciation

    Ivanovic, R., Gregoire, L., Burke, A., Wickert, A. D., Valdes, P. J., Ng, H. C., Robinson, L. F., McManus, J. F., Mitrovica, J. X., Lee, L. & Dentith, J. E., 27 Jul 2018, In : Paleoceanography and Paleoclimatology. Early View, 18 p.

    Research output: Contribution to journalArticle

  3. Calibration of the B/Ca proxy in the planktic foraminifer Orbulina universa to Paleocene seawater conditions

    Haynes, L. L., Hönisch, B., Dyez, K. A., Holland, K., Rosenthal, Y., Fish, C. R., Subhas, A. V. & Rae, J. W. B., Jun 2017, In : Paleoceanography. 32, 6, p. 580-599

    Research output: Contribution to journalArticle

  4. The evolution of deep ocean chemistry and respired carbon in the Eastern Equatorial Pacific over the last deglaciation

    de la Fuente, M., Calvo, E., Skinner, L., Pelejero, C., Evans, D., Müller, W., Povea, P. & Cacho, I., Dec 2017, In : Paleoceanography and Paleoclimatology. 32, 12, p. 1371-1385 15 p.

    Research output: Contribution to journalArticle

ID: 252215512