EUROPE: In the past two hundred years, the strength of the Earth’s magnetic field has experienced a continuous weakening state. This led some scientists to deliberate if the planet’s magnetic field is due for a reversal at a distant future. A new study revealed that the planet’s protection against solar winds might just be waning down from a high rate.
Researchers from the Massachusetts Institute of Technology and Columbia University’s Lamont-Doherty Earth Observatory analyzed the planet’s average, steady magnetic field intensity in the past five million years. Using ancient rock samples emitted from the Galapagos Islands’ volcanoes, they found that the magnetic field’s past intensity is only 60 percent of today’s field strength.
The volcanoes are located on the planet’s equator where the magnetic field’s strength is precisely half of the poles’ strength. Rocks emitted from the volcanoes contain iron, which align with the planet’s magnetic field just like tiny magnets. This suggests that the current state of the planet’s protection won’t flip in the foreseeable future. Findings suggest that humankind has a long way to go before the field reaches an unstable level which could prompt a reversal.
“It makes a huge difference, knowing if today’s field is a long-term average or is way above the long-term average. Now we know we are way above the unstable zone. Even if the [field intensity] is dropping, we still have a long buffer that we can comfortably rely on,” said lead author Huapei Wang, a postdoc at the Department of Earth, Atmospheric and Planetary Sciences at MIT.
