What happens when the magnetic field of Earth reverses? This does happen naturally in about 250,000 years and the effects of such a reversal will be fascinating. However from past fossil records, we cannot find any significant effects on living organisms.
Theoretically the field reversal which means North Magnetic pole shifting to Antarctica and the South Magnetic pole shifting to the Arctic region could lead to a period when the field goes Zero for a century or so. This would let the cosmic rays to freely penetrate the planet and cause mutations in its living flora and fauna. However there are not much record of any such occurrence in the past.
There have been dozens of field reversals in the last few million years. This has been documented in the rock which has emerged and solidified along the mid-Atlantic Ridge where continental plates are slowly separating. This era is fixed in the form of parallel bands all along the ridge where the rock has stored a fossilized image of the local orientation of the Earth’s magnetic field for the last few million years.
Coming to the basic question could the world turn upside down, I mean magnetically speaking? Yes it can as per study done by a joint group of researchers from Europe and America.
If such a change happens, it can send every compass on Earth with the needles pointing South instead of North. This is not the first time this has happened. In the past such geomagnetic reversals have happened though it did not occur overnight. However, it is not a protracted process according to the latest studies into the ancient Italian lake sediments which shows Earth’s last magnetic reversal 786,000 years ago occurred in less than 100 years.
A team of researchers from Italy, France, Columbia University and the University of California, Berkeley, found that the last magnetic reversal 786,000 years ago happened over a relatively brief period of 100 years.
New evidence hints that the intensity of the Earth’s Magnetic Field is falling 10 times faster than normal. This has led to geophysicists to forecast a magnetic field reversal in a few thousand years.
The fact that Earth’s magnetic field is decreasing 10 times faster has led scientists to conclude that the magnetic field will once again reverse within a few thousand years. Earth’s magnetism is driven by the convection in Earth’s iron core and the pole reversal have happened in the past without any apocalyptic events as a result of it as far as geological records can tell.
Earth’s magnetic field protects life on the planet from high energy particles from the Sun and cosmic rays. So if the magnetic flipping is preceded by extended periods of unstable magnetic behavior, it could endanger life on Earth.The abrupt flip over known as Matuyama-Brunhes transition is often preceded by long periods of magnetic instability. This is the main cause of the worry for scientists who fear a surge in incidence of genetic mutation due to the weakening of the magnetic field.