Recently, I posted an article on my blog about the earth’s magnetic field (geomagnetic field) and how it protects us from incoming solar and cosmic radiation. The geomagnetic field is a quasi-static field. The lines of force protect us from incoming ionizing radiation from the sun and space by directing high energy particles towards the poles. These force lines are, in some ways, similar to the force lines surrounding a bar magnet. The field lines which exit the southern pole and re-enter into the northern pole are created by a rotating molten iron core and around a solid inner core of iron. There are some fascinating aspects to the geomagnetic field:
- it is not uniform in its strength around the world
- the field lines are normally vibrating slightly and bounce more during solar storms
- the field strength is constantly changing – currently it is in a period of weakening
- the north pole is currently drifting westward
- the field reverses poles (north and south switch) approximately every 450,000 years
- the last flip occurred approximately 780,000 years ago
We are overdue for the geomagnetic pole reversal. It takes between 1 and 10,000 years to complete the reversal. Having said this, there have been periods of millions of years of stability. Are we in a period of long stability or are we overdue for the Big Flip? What will happen to life on earth when the flip happens? Nobody really knows the answer? On a bright note, the planet has survived hundreds if not thousands of these reversals. It is also of great comfort to note that many animals with us today such as giant sea turtles have survived these reversals.
There is little to no fossil evidence to support mass extinctions from a weakening and reversing geomagnetic field. One thing that does seem likely is that animals such as birds, turtles, and bees which rely on the magnetic field for navigation will likely have a period of re-adjustment to the new reality. In addition, if we continue to rely on satellites and radio waves and microwaves for communication – we can most likely expect disruptions if not destruction of this mode of communication.
Nothing to get too paranoid about – we still have to make it through the Mayan Prophecy predicting the end of the world in December 2012 (tongue firmly planted in cheek).
Dr. Brett Wade is an instructor at Okanagan College in the Therapist Assistant Program. He is also a Registered Physiotherapist and practices part-time seeing patients with chronic health problems. His area of interest and research is in the health effects of non-ionizing radiation. Blog: www.drbrettwade.com