Sound Reversal – Hearing Earth’s magnetic field switch poles 780k years ago

The Earth’s magnetic field is invisible and cannot be sensed by the human body. Yet, it plays a crucial role for life: besides its most prominent role in navigation, it serves as a protective shield against harmful solar and cosmic radiation. Among the most dramatic variations of the Earth’s magnetic field are reversals, marked by a significant decrease in field intensity and a complete flip of the magnetic poles. Geomagnetic reversals are well-documented in paleomagnetic records spanning Earth's geological history. They are considered a natural characteristic of the geomagnetic field and occur very irregularly, on average, a few times per million years.

To make the drastic, global changes of the Earth’s magnetic field accessible to a general audience, we present an audio-visual representation of the most recent reversal, known as the Matuyama-Brunhes reversal, which took place 780,000 years ago. Both the visual and sonic depictions are based on a global model, resting on an extensive compilation of global paleomagnetic sediment records.

Building on our previous experience in engaging audiences through outreach projects (e.g. Nielsen, K., & Hayes 2025; Schanner et al. 2024; Nielsen et al. 2022), we find that the combined audio-visual format provides an intuitive, corporeal, and immersive experience – one that to a far better extent than text and graphs can capture the attention of the general public.

 

Nielsen, K., & Hayes, L. (2025) The Sun, https://www.instagram.com/p/DEZqSqANIjN/?img_index=1 (approx 228K plays)

Schanner, M., Kervalishvili, G, & Nielsen, K. (2024) Sonification of the Laschamp event, https://www.instagram.com/p/DBJVujeIC-T/ (approx 61K plays)

Nielsen, K., Linden-Vörnle , N., & Kloss, C. (2022) The scary sound of Earth’s magnetic field, https://soundcloud.com/esa/the-scary-sound-of-earths-magnetic-field (approx 1.15M plays)