Context: Scientists have tracked climate change by following the Paleomonsoonal pattern of the subcontinent by harnessing magnetic mineralogy. 

About the study:

  • The study involves scientists from Indian Institute of Geomagnetism (IIG), an autonomous institute of the Department of Science & Technology, Government of India.
  • The study conducted climatic and environmental studies by collecting sediment samples from different environments and climatic domains of India to obtain the information frozen in magnetic minerals in the form of magnetic parameters like magnetic susceptibility etc.
  • The magnetic minerals are sensitive to the physical and chemical environment that they are embedded in. 
  • These external changes bring about modifications in the innate structure of these magnetic minerals, transitioning them from one magnetic phase to another. 
  • In this process, the magnetic mineralogy also changes. For example, from magnetite to hematite and vice versa.  

Findings of the study: 

The mineral magnetic studies have unraveled 4 regional climatic features encompassing the entire Indian subcontinent and one localized climatic event.

  • Higher monsoon precipitation in the western part of India was shown to be analogous with glacial melt in the Himalayas. 
  • The weakening of monsoon was inferred in the Himalayas and the hinterland of Arabian sea, analogically cold and dry conditions were prevalent at Dhakuri(Uttarakhand), which led to the formation of loess deposits. 
  • The monsoon intensification is deciphered in the western and eastern part of India with major implications in the hinterlands of the Arabian Sea and Bay of Bengal. 
  • Holocene aridity and weakened monsoon was inferred to be prevalent across the subcontinent. The Holocene is the current geological epoch.
  • The localized feature of Younger Dryas cooling seems to be confined to just the upper reaches of the Himalaya. Younger Dryas is a period of rapid cooling in the late Pleistocene.

Monsoons arise from the development of cross-equatorial pressure gradients produced by

the land–ocean–atmosphere system: differential heating of land and ocean produced by the different heat capacity of land and water

Importance of the study

  • New technique is faster, easier and cheaper: The Scientists used changes in properties of magnetic minerals for their research in India’s Paleomonsoonal pattern, which is comparatively faster, easier and cheaper.
  • More accurate forecast: As a result of natural and anthropogenic activities, climate is changing at a rapid pace. The research will help forecast climatic changes with more accuracy and speed.