Earth’s magnetic flips can last 70,000 years, new study finds, Pg11

Key Highlights:

• A new study reveals that Earth's magnetic field reversals can last up to 70,000 years.
• Researchers analyzed deep-sea sediment cores from the North Atlantic Ocean dating back 40 million years.
• The study challenges the previous belief that magnetic pole flips occur relatively quickly, around 10,000 years.
• The research team comprised scientists from France, Japan, and the U.S..

Detailed Insights:

• The Earth's magnetic field protects the planet from harmful solar radiation and aids in navigation.
• Analysis of sediment layers involved using X-ray scanning, magnetic measurements, and astronomical tuning.
• During a magnetic reversal, the field weakens, potentially exposing the atmosphere and surface life to increased solar radiation.
• The extended periods of weak magnetic field could have influenced ancient environments and the evolution of life.
• Numerical simulations of the Earth's core suggest that long reversals are a natural, though rare, part of the geodynamo's behaviour.

Scientific/Technical Concepts Involved:

• Geodynamo: The process by which the churning of liquid iron in the Earth's outer core generates the magnetic field.
• Magnetic Reversal: A phenomenon where the Earth's magnetic north and south poles switch places.
• Eocene Epoch: A geological period that occurred roughly 40 million years ago.