EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Cenozoic sea-level and cryospheric evolution from deep-sea geochemical and continental margin records

Kenneth Miller, James Browning, W. John Schmelz, Robert Kopp, Gregory Mountain, and James Wright
Kenneth Miller et al.
  • Department of Earth & Planetary Sciences and Institute of Earth, Ocean and Atmospheric Sciences, Rutgers University, Piscataway, New Jersey 08854, USA (

Cenozoic (past ~66 Myr) sea-level history reflects temperature changes and cryospheric evolution of the Earth from essentially ice-free conditions in the Early Eocene to bipolar ice sheets in the Quaternary. We derived a global mean sea level (GMSL) estimate for the Cenozoic using a new astronomically calibrated Pacific benthic foraminiferal δ18O splice from published records and a 2 Myr-smoothed Pacific bottom water temperature record based on published benthic foraminiferal Mg/Ca data. Our GMSL estimates are similar to sea-level estimates derived from “backstripping” (progressively accounting for compaction, loading and thermal subsidence) of cores from the mid-Atlantic U.S. continental margin. Peak global warmth, elevated GMSL, high CO2, and largely ice-free conditions occurred during the Early Eocene “Hothouse.” During the Middle-Late Eocene “Cool Greenhouse,” small ice sheets associated with lower atmospheric CO2 drove sea-level changes. Continental-scale ice sheets began in the Oligocene “Icehouse” (ca. 34 Ma), a permanent East Antarctic ice sheet began in the middle Middle Miocene (ca. 12.8 Ma), and full, bipolar glaciation began in the Quaternary (ca. 2.55 Ma). The Last Glacial Maximum (20-27 ka) was the largest lowering of GMSL (~130 m) of the Mesozoic-Cenozoic and GMSL rise during last deglaciation (ca. 19-10 ka) exceeded 40-45 mm/yr.  Sea-level rise progressively slowed from 10 ka to 2 ka and was then at stillstand until late 19th to early 20th century when rates began to rise. Despite large uncertainties in proxies, our study reaffirms that throughout the Cenozoic, high long-term (107-year scale) CO2 was associated with warm climates and high sea levels.  However, sea level-change was dominated by periodic, astronomically controlled (10’s kyr-Myr scale) Milankovitch variations superimposed upon longer-term changes driven by CO2.

How to cite: Miller, K., Browning, J., Schmelz, W. J., Kopp, R., Mountain, G., and Wright, J.: Cenozoic sea-level and cryospheric evolution from deep-sea geochemical and continental margin records, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10017,, 2020


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