The Earth’s magnetic field, inherently dynamic and subject to continuous flux, is shaped by external forces that ultimately impact its strength, leading to fluctuations over time. This will lead to the movement of Earth’s magnetic north and south poles, resulting in gradual shifts and complete flips approximately every 300,000 years. The North Pole has shifted at a rate of roughly “15 km per year.” However, since the 1990s, this pace has accelerated, reaching about “55 km per year” towards Siberia, according to a BBC Science Focus report.
What is magnetic pole reversal?
The report said that the shift of Earth’s magnetic field poses potential risks to life, as it generates a protective barrier around the planet. This shield defends the Earth’s surface against the onslaught of particles from the Sun’s solar wind and high-energy cosmic rays from outer space.
This phenomenon is significant for navigation, including human use of compasses and the internal magnetic compasses relied upon by certain animals such as birds, fish, and sea turtles.
Period of magnetic pole reversal
– NASA, citing the paleomagnetic records, said Earth’s magnetic poles have reversed 183 times in the last 83 million years and several hundred times over the past 160 million years.
– The time intervals between reversals have varied widely but average around 300,000 years. The last reversal occurred approximately 780,000 years ago.
– Over the past 200 years, Earth’s magnetic field has weakened by about nine per cent globally. Despite this weakening, scientists have no reason to believe a pole reversal is imminent.
– Paleomagnetic studies indicate that Earth’s magnetic field is as strong as it has been in the past 100,000 years and is twice as intense as its million-year average. Some scientists estimate that the field’s strength might completely decay in about 1,300 years. However, the current weakening could halt at any time.
– Fossils from the last major pole reversal period show no significant plant and animal life changes. Deep ocean sediment samples suggest stable glacial activity. Geologic and fossil records from previous reversals also show no remarkable events, such as doomsday scenarios or major extinctions.
When was the shift in poles first detected?
According to NASA, the precise location of Earth’s magnetic North Pole was initially determined in 1831. Since then, it has steadily drifted north-northwestward by over 600 miles (1,100 km), with its forward velocity accelerating from approximately 10 miles (16 km) per year to about 34 miles (55 km) per year.
This gradual movement affects navigation and necessitates regular adjustments. However, limited scientific evidence suggests substantial connections between Earth’s shifting magnetic poles and climate.
Earth’s magnetosphere gives protection
The Earth’s magnetosphere acts as a protective barrier, preventing harmful energy forms from reaching the planet’s surface and confining them safely away.
According to NASA, most of this undesirable energy is contained within twin doughnut-shaped regions known as the Van Allen Belts, which are situated at a secure distance from Earth’s surface.