From UPSC perspective, the following things are important :
Prelims level : Laschamp Excursion
Mains level : Mass Extinction
This newscard is an excerpt from the original article published in DownToEarth.
The world experienced a few centuries of apocalyptic conditions 42,000 years ago, triggered by a reversal of the Earth’s magnetic poles combined with changes in the Sun’s behaviour. This event is called as Laschamps Excursion.
Try this PYQ from CSP 2018:
Q.The term “sixth mass extinction/sixth extinction” is often mentioned in the news in the context of the discussion of
(a) Widespread monoculture Practices agriculture and large-scale commercial farming with indiscriminate use of chemicals in many parts of the world that may result in the loss of good native ecosystems.
(b) Fears of a possible collision of a meteorite with the Earth in the near future in the manner it happened 65million years ago that caused the mass extinction of many species including those of dinosaurs.
(c) Large scale cultivation of genetically modified crops in many parts of the world and promoting their cultivationin other Parts of the world which may cause the disappearance of good native crop plants and the loss offood biodiversity.
(d) Mankind’s over-exploitation/misuse of natural resources, fragmentation/loss, natural habitats, destructionof ecosystems, pollution and global climate change.
- The Laschamp event was a geomagnetic excursion (a short reversal of the Earth’s magnetic field). It occurred 41,400 years ago, during the end of the Last Glacial Period.
- This event is named after the village where it was discovered in the French Massif Central.
- It led to series of catastrophic events like the ozone layer was destroyed, electrical storms raged across the tropics, solar winds generated spectacular light shows (auroras), Arctic air poured across North America, ice sheets and glaciers surged and weather patterns shifted violently.
- During these events, life on earth was exposed to intense ultraviolet light, Neanderthals and giant animals known as megafauna went extinct, while modern humans sought protection in caves.
The Adams Event
- This last major geomagnetic reversal triggered a series of dramatic events that have far-reaching consequences for our planet.
- Because of the coincidence of seemingly random cosmic events and the extreme environmental changes found around the world 42,000 years ago, researchers have called this period the “Adams Event”.