The magnetic field of Earth acts as a protective shield against cosmic radiation and solar particles, constantly changing and occasionally flipping its poles. Magnetic field excursions are brief periods where the intensity weakens, and the familiar dipole structure disappears, replaced by multiple poles. The Laschamps excursion, around 41,000 years ago, is a well-studied example of this phenomenon, showing decreased protection from harmful space rays.
Scientists study cosmogenic radionuclides in ice and marine sediment cores to understand past cosmic ray bombardment on Earth’s surface. These isotopes are created by cosmic rays interacting with the atmosphere, providing insights into the history of cosmic radiation exposure.
Lower paleomagnetic field intensity periods are associated with higher cosmogenic radionuclide production, indicating reduced shielding. Sanja Panovska, a researcher at GFZ Potsdam, Germany, will present her research on the relationship between paleomagnetic field intensity and cosmogenic nuclides during the Laschamps excursion at the upcoming European Geosciences Union (EGU) General Assembly 2024.
2024-04-21 09:51:02
Original article available at phys.org