Comparing ocean temperatures across sites only works if every record is on the same clock. MioAGE evaluates, harmonises and, where needed, revises the age models behind the MioOcean temperature records.
69
sites evaluated
38
key sites synchronised
53
age models verified, 33 of them revised
Why ages matter
To understand how Miocene climate evolved, we need to know when changes happened, how fast they unfolded, and whether records from different ocean basins describe the same moment in time. Miocene records are dated with a mix of biostratigraphy, magnetostratigraphy, chemostratigraphy, astrochronology and radiometric dating, often on different depth scales and older timescales. Without a common chronological framework, apparent differences between sites can simply reflect differences in their age models rather than real differences in climate.
The effect is not trivial: across more than 10,000 MioOcean temperature data points, synchronising the age models shifted ages by 28 kyr on average, which matters at orbital (Milankovitch) timescales. For some records the change was several million years, enough to move observations into a different part of the Miocene.
What MioAGE does
MioAGE developed MioOcean Chronoinformatics, an approach for organising, evaluating, preserving and updating chronological information rather than treating published ages as fixed. It has three parts:
- The MioAGE Survey, a community-based evaluation of the chronologies behind the compiled temperature records.
- The MioOcean Age Framework, in which key sites are verified, standardised and, where needed, revised using biostratigraphy, magnetostratigraphy and/or astrochronology, all anchored to the Geologic Time Scale 2012.
- The MioAGE Reliability Grid, which assesses age model quality and reporting quality at each key site.
The results are stored in the open, machine-readable MioOcean Age Model Database, which keeps the depth and age models together with their tie points, metadata and provenance. This means records can be re-evaluated and updated as stratigraphic calibrations and timescales continue to evolve.
Explore the age models
Use the interactive dashboard below to browse the MioOcean key sites and their revised age models.
Using the MioOcean age models? Please cite the MioAGE paper (Drury, Tangunan et al., 2026) and the MioOcean age model compilation on Zenodo.