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NASA Is Tracking a Vast, Growing Anomaly in Earth's Magnetic Field:

The South Atlantic Anomaly (SAA) – likened by NASA to a 'dent' in Earth's magnetic field, or a kind of 'pothole in space' – generally doesn't affect life on Earth, but the same can't be said for orbital spacecraft (including the International Space Station), which pass directly through the anomaly as they loop around the planet at low-Earth orbit altitudes.

[...] The primary source is considered to be a swirling ocean of molten iron inside Earth's outer core, thousands of kilometres below the ground. The movement of that mass generates electrical currents that create Earth's magnetic field, but not necessarily uniformly, it seems.

A huge reservoir of dense rock called the African Large Low Shear Velocity Province, located about 2,900 kilometres (1,800 miles) below the African continent, disturbs the field's generation, resulting in the dramatic weakening effect – which is aided by the tilt of the planet's magnetic axis.

"The observed SAA can be also interpreted as a consequence of weakening dominance of the dipole field in the region," says NASA Goddard geophysicist and mathematician Weijia Kuang.

"More specifically, a localised field with reversed polarity grows strongly in the SAA region, thus making the field intensity very weak, weaker than that of the surrounding regions."

[...] one study led by NASA heliophysicist Ashley Greeley in 2016 revealed the SAA is drifting slowly in a north-westerly direction.

It's not just moving, however. Even more remarkably, the phenomenon seems to be in the process of splitting in two, with researchers this year discovering that the SAA appears to be dividing into two distinct cells, each representing a separate centre of minimum magnetic intensity within the greater anomaly.

Journal Reference:
A. D. Jones, S. G. Kanekal, D. N. Baker, et al. SAMPEX observations of the South Atlantic anomaly secular drift during solar cycles 22–24, Space Weather (DOI: 10.1002/2016SW001525)

Original Submission

1. "upstart" - https://soylentnews.org/~upstart/
2. "NASA Is Tracking a Vast, Growing Anomaly in Earth's Magnetic Field" - https://www.sciencealert.com/nasa-is-tracking-the-mysterious-evolving-anomaly-in-earth-s-magnetic-field
3. "likened by NASA" - https://www.sciencealert.com/mysterious-anomaly-weakening-earth-s-magnetic-field-seems-to-be-splitting-into-two
4. "swirling ocean of molten iron" - https://www.sciencealert.com/new-study-shows-that-earth-s-magnetic-field-is-weakening-more-rapidly-than-we-thought
5. "African Large Low Shear Velocity Province" - https://www.sciencealert.com/something-mysterious-under-southern-africa-dramatically-weakening-earth-s-magnetic-field-south-atlantic-anomaly
6. "says" - https://www.nasa.gov/feature/nasa-researchers-track-slowly-splitting-dent-in-earth-s-magnetic-field
7. "one study" - https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016SW001525
8. "appears to be dividing into two distinct cells" - https://www.sciencealert.com/mysterious-anomaly-weakening-earth-s-magnetic-field-seems-to-be-splitting-into-two
9. "10.1002/2016SW001525" - https://doi.org/10.1002/2016SW001525
10. "Original Submission" - https://soylentnews.org/submit.pl?op=viewsub&subid=42821

printed from SoylentNews, NASA is Tracking a Vast, Growing Anomaly in Earth's Magnetic Field on 2023-07-17 22:17:31