Wed Feb 19 00:30:00 UTC 2025: ## Mystery of Pacific Ocean’s Beryllium-10 Spike Baffles Scientists

**CANBERRA, Australia (February 19, 2025)** – Analysis of a 20-million-year-old ferromanganese crust from the Pacific Ocean floor has revealed a significant anomaly in beryllium-10 levels dating back 10 million years. The unexpected surge in this radioactive isotope, reported in *Nature Communications*, is prompting scientists to explore a range of potential explanations for this geological puzzle.

Dr. Dominik Koll, honorary lecturer at the Australian National University, led the research. By analyzing the layered growth of the crust – similar to reading tree rings – Koll and his team used accelerator mass spectrometry to measure beryllium-10 concentrations. The isotope’s consistent decay rate typically allows for precise dating, but the study revealed a sharp increase 10 million years ago before returning to its normal pattern.

The team ruled out measurement errors through rigorous repetition and cross-referencing samples from different locations. Several hypotheses are being considered to account for the anomaly, including:

* **Shift in Global Ocean Currents:** The intensification of the Antarctic Circumpolar Current around 12 million years ago might have disrupted global ocean circulation patterns, affecting beryllium-10 distribution. Further research involving samples from other oceans is needed to test this hypothesis.

* **Interstellar Collision:** A collision with a dense interstellar cloud could have compressed the heliosphere, exposing Earth to heightened cosmic radiation and thus increasing beryllium-10 production.

* **Near-Earth Supernova:** A nearby supernova explosion could also have increased cosmic ray flux, resulting in the observed beryllium-10 spike.

The discovery has significant implications for geological dating. This unexpected anomaly provides a new time marker for correlating various geological records (ice cores, sediments, speleothems) spanning millions of years, which is crucial for understanding Earth’s climate history. Koll and his team are continuing their research to pinpoint the cause of the beryllium-10 spike and its impact on our understanding of Earth’s past.

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