NASA Is Tracking a Huge, Growing Anomaly in Earth’s Magnetic Field

Source: The post is based on the article “NASA Is Tracking a Huge, Growing Anomaly in Earth’s Magnetic Field” published in Science Alert on 24th March 2023

What is the News?

NASA is actively monitoring South Asian Anomaly in Earth’s magnetic field.

What is South Asian Anomaly?

The South Atlantic Anomaly signifies the weakening of the Earth’s magnetic field between Africa and South America.

This anomaly exists because the Earth’s inner Van Allen radiation belt comes closest to the planet’s surface, causing an increased flux of energetic particles.

Note: A Van Allen radiation belt is a zone of energetic charged particles, most of which originate from the solar wind, that are captured by and held around a planet by that planet’s magnetosphere.

Impact of South Asian Anomaly:

South Atlantic Anomaly(SAA) generally doesn’t affect life on Earth, but the same can’t be said for orbital spacecraft which pass directly through the anomaly as they loop around the planet at low-Earth orbit altitudes.

During these encounters, the reduced magnetic field strength inside the anomaly means technological systems onboard satellites can short-circuit and malfunction if they become struck by high-energy protons emanating from the Sun.

What causes South Asian Anomaly?

The primary source is considered to be a swirling ocean of molten iron inside Earth’s outer core, thousands of kilometers below the ground. The movement of that mass generates electrical currents that create Earth’s magnetic field, but not necessarily uniformly.

A huge reservoir of dense rock called the African Large Low Shear Velocity Province, located about 2,900 kilometers (1,800 miles) below the African continent, disturbs the field’s generation resulting in the dramatic weakening effect – which is aided by the tilt of the planet’s magnetic axis.