It seems this topic is becoming more mainstream all the time.
What is the South Atlantic Anomaly?
The Earth’s magnetic field, generated deep within the planet, is a shield against particle radiation from space. In the South Atlantic this shield
is much weaker than elsewhere across the globe and radiation from space therefore penetrates deeper into the atmosphere. This region is known as the
South Atlantic Anomaly (SAA) and the radiation in the SAA is a known hazard to satellites, spacecraft and high-altitude aircraft.
This anomaly deserves a great deal of attention as it is growing.
A magnetic reversal in progress?
The South Atlantic Anomaly (SAA) is known to be growing in extent and spreading westwards from South Africa, as the Earth’s internal magnetic field
rapidly weakens in this region. This may be early evidence of a forthcoming reversal in the direction of the Earth’s internal magnetic field. We do
not know in detail precisely what occurs during such reversals, including the changes observed in the magnetic field and the time a reversal takes to
complete. However these factors are important in knowing where the radiation risk may be increased and how the atmosphere might respond.
Earth’s magnetic field has had many highs, lows and reversals in its past. The last reversal was around 800,000 years ago. So the Earth is known to
be able to re-generate its field and has done so during human pre-history. Understanding the development of the SAA may therefore be significant in
understanding the reversal process and its impact on life and the natural environment.
Notice the last reversal was around 800,000 years ago. Seems we are likely due for one soon.
More info at the link:
South Atlantic Anomaly and South Georgia Magnetic Observatory
CU
edit on 1/10/2011 by CUin2013? because: Spelling, duh...