My answers to questions on science - Part 7

Image Source: Google

The Earth’s geologic record shows that hundreds of magnetic pole reversals have occurred throughout it’s history; they happen when patches of iron atoms in Earth’s liquid outer core become reverse-aligned, like tiny magnets oriented in the opposite direction from those around them.

Earth's magnetic field has flipped about 170 times in the last 100 million years, with the last major reversal happening 780,000 years ago (2).

When the reversed patches grow to the point that they dominate the rest of the core, Earth's overall magnetic field flips. The last reversal happened 780,000 years ago during the Stone Age, and indeed there's evidence to suggest the planet may be in the early stages of a pole reversal right now. (1)

Earth's magnetic field takes between 1,000 and 10,000 years to reverse, and in the process, it greatly diminishes before it re-aligns. It's not a sudden flip, but a slow process, during which the field strength becomes weak, very probably the field becomes more complex and might show more than two poles for a while, and then builds up in strength and [aligns] in the opposite direction.

A flip doesn't happen overnight. Instead, it takes anywhere from a century to 20,000 years to complete, and it's accompanied by a decline in strength of the magnetic field

It's the weak in-between phase that would be roughest on living beings on Earth.

If Earth's magnetic poles reversed instantaneously, the most immediate consequence would be a significant weakening of the magnetic field, potentially exposing the planet to increased solar radiation and cosmic rays, disrupting communication systems, navigation technologies reliant on the magnetic field, and potentially impacting migratory animals that use it for orientation; however, while concerning, this wouldn't likely cause a catastrophic event as the atmosphere still provides some protection, and past magnetic reversals haven't shown evidence of mass extinctions.

Magnetic pole reversals naturally happen over thousands of years, allowing life on Earth to adapt gradually.

So an instantaneous magnetic pole reversal can bring these things into focus

Weakened magnetic field: During the transition period, the magnetic field would significantly weaken, allowing more charged particles from the sun (solar wind) to reach Earth's atmosphere, potentially causing increased auroras at lower latitudes.

Severe disruption to technology: GPS systems, compasses, and other devices relying on the magnetic field for navigation would be severely affected, potentially causing malfunctions. We have to face severe power outages . The disruptions in the Earth's magnetic field could result in interference with radio communications, making it difficult to transmit and receive messages.

Impact on migratory animals: Animals like birds, whales, and sea turtles that use the Earth's magnetic field for navigation could become disoriented during the reversal.

Potential health concerns: With the Earth's magnetic field weakened, high levels of radiation would reach the surface, potentially exposing human and animal life to radiation sickness. Increased exposure to radiation could theoretically increase the risk of certain cancers in humans, although the atmosphere would still provide some shielding.

Increased atmospheric drag: The weakened magnetic field would allow the Earth's atmosphere to expand, increasing atmospheric drag.

Change in weather patterns: The sudden switch of the magnetic pole could result in shifts in ocean currents, leading to changes in climate and weather patterns.

Footnotes:

1. What If Earth's Magnetic Poles Flip?
2. What If Earth's Magnetic Field Flipped?