Beryllium-10 anomaly paves new path in Earth's dating methods
Scientists have discovered an anomaly in the increased levels of beryllium-10 found in ocean sediments on the Pacific Ocean floor. According to the portal Interesting Engineering, this could improve our understanding of dating the Earth. The discovery may be linked to an event from 10 million years ago.
Researchers from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), in collaboration with TUD Dresden University of Technology and the Australian National University, identified an unexpected rise in beryllium-10 levels in samples from the Pacific seabed. This finding could serve as a global time marker, aiding in the synchronization of geological records spanning millions of years.
Invaluable tool for reconstructing Earth's history
Beryllium-10 is a rare radioactive isotope produced when cosmic rays collide with oxygen and nitrogen in the atmosphere. It gradually falls to Earth and accumulates in ocean sediments. Its half-life of 1.4 million years allows us to track events from up to 10 million years ago. Interesting Engineering highlights that it "provides valuable insights into the Earth's geological history."
The team led by Dr. Dominik Koll examined ferromanganese crusts from the Pacific seabed, which contain records of environmental changes. Using accelerator mass spectrometry, the researchers precisely measured the beryllium-10 content in the samples.
Scientists did not expect such a discovery
The research results were surprising. "At around 10 million years, we found almost twice as much beryllium-10 as we had anticipated. We had stumbled upon a previously undiscovered anomaly," reported Dr. Koll. The team ruled out contamination by analyzing additional samples from various locations, which showed the same pattern.
Scientists are exploring two hypotheses to explain this anomaly. One suggests changes in ocean currents near Antarctica may have influenced the uneven distribution of beryllium-10. Alternatively, the intensity of cosmic radiation might have increased due to a nearby supernova.
If this anomaly is found to occur globally, the astrophysical hypothesis gains relevance. Otherwise, changes in ocean circulation are a more likely explanation. This discovery could revolutionize geological dating, assisting in synchronizing different geological archives.
