Earth's magnetic field losing its grip
Published on Oct 3, 2012 11:59 PM
LONDON (REUTERS)- The only thing stopping Earth having a lifeless environment like Mars is the magnetic field that shields us from deadly solar radiation and helps some animals migrate, and it may be a lot more fragile than one might think.
Scientists say earth's magnetic field is weakening and could all but disappear in as little as 500 years as a precursor to flipping upside down.
It has happened before - the geological record suggests the magnetic field has reversed every 250,000 years, meaning that, with the last event 800,000 years ago, another would seem to be overdue.
"Magnetic north has migrated more than 1,500 kilometres over the past century," said Conall Mac Niocaill, an earth scientist at Oxford University. "In the past 150 years, the strength of the magnetic field has lessened by 10 per cent, which could indicate a reversal is on the cards." Earth's magnetic field has always restored itself but, as it continues to shift and weaken, it will present challenges - satellites could be more exposed to solar wind and birds, bees and some fish which use the field could be mightily confused.
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