Overview

• New research reveals that the Laschamps event around 41,000 years ago led to a significant decrease in Earth's magnetic field strength, increasing exposure to cosmic rays.
• The event is marked by a temporary but intense decrease in geomagnetic protection, which scientists link to potential upheavals in Earth's biosphere.
• Measurements of beryllium-10 in ice and marine cores indicate that cosmic ray bombardment was twice as high during the Laschamps excursion as it is today.
• Geomagnetic reconstructions show that Earth's magnetosphere shrank dramatically during the event, reducing its ability to shield against space radiation.
• Understanding these geomagnetic excursions is crucial for predicting future events and assessing their potential impacts on the Earth system.