Changes of circulation pattern in the Southern Ocean have been invoked to explain a significant portion of the increase in the atmospheric carbon dioxide during the last deglaciation. However, the accurate timing and thus underlying mechanisms of these changes are still controversial, requiring knowledge of different water masses movements with absolute age constraints. Aragonitic scleractinian deep-sea corals, recovered from a broad range of depths in the Drake Passage, provide a unique opportunity to investigate Southern Ocean ventilation with precise U-Th age control. A rapid age-screening technique achieved by coupling a laser system to Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS) enables us to get an approximate age distribution of the coral samples in order to select appropriate specimens for more accurate isotope-dilution age and radiocarbon age determination. Thus far more than 1800 deep-sea corals from the Drake Passage have been dated using this and other techniques, and about 400 samples have been dated precisely using isotope-dilution method. The age results show that deep-sea corals can be found across nearly the whole of the last deglaciation across a wide range of depths and locations. With known radiocarbon contents and U-Th ages of the deep-sea corals, the ventilation state of different water masses in the past can be assessed based on their decay-corrected 14C activities. This data submission includes all U-Th and 14C data available for the Drake Passage corals. Funding was provided by the NERC standard grant NE/N003861/1.

Changes of circulation pattern in the Southern Ocean have been invoked to explain a significant portion of the increase in the atmospheric carbon dioxide during the last deglaciation. However, the accurate timing and thus underlying mechanisms of these changes are still controversial, requiring knowledge of different water masses movements with absolute age constraints. Aragonitic scleractinian deep-sea corals, recovered from a broad range of depths in the Drake Passage, provide a unique opportunity to investigate Southern Ocean ventilation with precise U-Th age control. This data submission includes trace element and delta11B for Drake Passage corals. Funding was provided by the NERC standard grant NE/N003861/1.

This dataset comprises neodymium (Nd) isotopic compositions measured on 145 samples of aragonitic deep-sea corals from the Drake Passage of the Southern Ocean. Most of the samples were previously collected on expeditions NBP0805 and NBP1103 on the RV Nathaniel B. Palmer. The samples include glacial, deglacial and Holocene aged specimens and most are from 0-40 ka BP (thousand years before present) based on uranium-thorium dating. Neodymium isotope analyses were conducted by either thermal ionisation mass spectrometry (TIMS) or multi-collector inductively-coupled plasma mass spectrometry (MC-ICP-MS) in the MAGIC laboratories at Imperial College London by David Wilson, Torben Struve and Tina van de Flierdt. In the modern ocean, dissolved Nd isotopes are a quasi-conservative water mass tracer, while past compositions of seawater are recorded in deep-sea corals. This dataset therefore provides evidence on the proportions of Atlantic versus Pacific waters admixed in the Southern Ocean through time, which places crucial constraints on global deep water chemistry and circulation dynamics during past climate events. Funding was provided by the NERC grant NE/N001141/1. Related datasets are associated with grant NE/N003861/1. Both grants funded the project "Bridging the Timing Gap: Connecting Late Pleistocene Southern Ocean and Antarctic Climate Records".

Isotopic analyses of oxygen, carbon and deuterium conducted on lakewater samples collected from Moutonnee, Ablation and Citadel Bastion Lakes on Alexander Island.

Dataset is comprised of stable isotopes (oxygen and carbon) of benthic foraminifera from sediments from International Ocean Discovery Program (IODP) Expedition 382, Site U1534, South Falkland Sediment Drift. 53.18967 S, 58.76083 W (605 m water depth). The sediment cores were collected from 3 holes using the advanced piston corer onboard RV Joides Resolution from site U1534 between 29/03/2019 and 02/04/2019. Suitable specimens of benthic foraminifera were identified and picked from the >250 micron size fraction sediment at BAS between March 2020 and May 2021. Isotope analysis was carried out between March-August 2021. The data were collected as part of a project aiming to investigate the sensitivity of the Atlantic Meridional Overturning Circulation to variability in Pacific-Atlantic connectivity via the ''cold water route''. Dr Victoria Louise Peck was the principle investigator for this project. Funding provided by NERC UKIODP moratorium grant NE/T010908/1 and analytical support from NEIF steering committee application IP-1950-119.

Ice sheet model runs based on the Glimmer thermo-mechanical ice sheet model. Glacial modelling was used to simulate former WAIS (West Antarctic Ice Sheet) dynamics (specifically grounding line and ice volume changes) in the Weddell Sea embayment, constrained by newly acquired field data (see related datasets).