On the Fidelity of Oxygen Isotope‐Based Sea Level Reconstructions: A Case Study of Marine Isotope Stage 3 Journal Article uri icon

Overview

abstract

  • Abstract; ; Although foraminiferal oxygen isotope records (δ; 18; O; F; ) have long been used to develop time‐continuous estimates of past global ice volume, growing evidence indicates that the ice volume and temperature contributions to δ; 18; O; F; diverge considerably over the last glacial cycle. Across Marine Isotope Stage 3 (MIS 3; 57 to 29 ka), estimates of peak global sea level based on δ; 18; O; F; are ∼30 m lower than reconstructions based on recent glacial geology, geologic sea‐level records, and glacial isostatic adjustment (GIA) modeling approaches. Here we address this mismatch by quantifying uncertainties in converting δ; 18; O; F; to global sea level during MIS 3. We review the geochemical tools to assess the contributions of ocean temperature, diagenesis, and the isotopic composition of ice sheets to δ; 18; O; F; records across MIS 3. We show that recent advances in our understanding of these and other factors that contribute uncertainty (e.g., global sea level during the Last Glacial Maximum) help to explain the MIS 3 gap between global sea level estimates based on δ; 18; O; F; and GIA analyses of geologic sea‐level records. We find that the accuracy and precision of MIS 3 ocean temperature reconstructions is likely a key contributor, and various MIS 3 temperature reconstructions can reduce the “gap” by 30%–70% (∼10–20 m). Future improvements in the precision of temperature reconstructions will better constrain the ice volume component of δ; 18; O; F; records. Ultimately, assessing the fidelity of δ; 18; O; F; as a proxy for global ice volume is key to disentangling the feedbacks between climate and ice sheets over the Pleistocene.;

publication date

  • October 1, 2026

Date in CU Experts

  • October 15, 2026 9:57 AM

Full Author List

  • Pico T; Farmer JR; Shackleton S; Poirier RK; Markle BR; Lisiecki LE

author count

  • 6

Other Profiles

International Standard Serial Number (ISSN)

  • 2572-4517

Electronic International Standard Serial Number (EISSN)

  • 2572-4525

Additional Document Info

volume

  • 41

issue

  • 10

number

  • e2026PA005469