In 2025, scientists have made a groundbreaking discovery, unearthing the oldest ice core to date, stretching back approximately 5 million years. This remarkable ice core, retrieved from the Ong Valley in the Transantarctic Mountains, offers an unprecedented window into Earth's climate during the Pliocene epoch. The analysis of this core promises to refine our understanding of future climate patterns.
Unlocking Climate History
Researchers employed cosmogenic nuclide dating techniques to analyze the ice core. These nuclides, produced by cosmic rays interacting with atmospheric elements, help determine the age of the material. The core revealed two distinct layers: the top layer dating back roughly 2.95 million years, and the bottom layer ranging from 4.3 to 5.1 million years old. These ages align with the Pliocene epoch, a period characterized by elevated global temperatures and CO2 levels.
Implications for Climate Science
The findings suggest that the East Antarctic Ice Sheet expanded during the Pliocene epoch. This expansion potentially predates the MIS M2 cooling event and coincides with early Pliocene global glaciation around 4.9-4.8 million years ago. This discovery offers direct evidence of past climate conditions and ice sheet dynamics, providing valuable insights for future climate models and predictions. Further research and analysis of additional samples are expected to provide more definitive conclusions about the Pliocene epoch.