Holocene Epoch, Glacial Lakes Outburst Floods and Stalagmites of Meghalaya Cave (Download PDF)

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Current period of geologic time. Refers to the last 11,700 years of the Earth՚s history. “The Age of Man” is another term sometimes used is the Anthropocene Epoch. The International Commission on Stratigraphy (ICS) had divided this Epoch in to three ages Greenlandian (began at 11,700 year) , Northgrippian (began at 8200 year) , Meghalayan (began at 4200 year points) .

International Commission on Stratigraphy (ICs)

  • A body of geological timekeepers.
  • Largest and oldest constituent scientific body in the International Union of Geological Sciences (IUGS) .
  • Primary objective is to precisely define global units (systems, series, and stages) .
  • Basic for the units (periods, epochs and age) of the International Geological Time Scale.
  • Sets global standards for the fundamental scale for expressing the history of the Earth.

Glacial Lakes Outburst Floods

  • Floods caused due to outbursts of lakes.
  • Formation is due to melting of glaciers.
  • Lakes are a subject of concern in the Sikkim Himalayan region.
  • Several lakes have been formed due to melting of scores of glaciers in the region.
  • Retreat of glaciers is expected to increase the number of glacier lakes and also expand the size of the existing ones.
  • The South Lhonak Lake in Sikkim at 7000 meters is one of the fast growing lakes out of 14 potentially dangerous lakes susceptible to GLOFs in the Sikkim Himalaya region. The lake has grown many folds since 1960s when it was small.
  • HDPE or High Density Polythene Pipes have been installed to siphon off water from the glacial lake to prevent any disasters due to outbursts.

Stalagmites of Meghalaya Cave-Predicting Northeast Monsoons

  • Connection between Northeast monsoon and El Nino.
  • Help of rock formations in Meghalaya.
  • Rock formations in a cave near Cherrapunji in Meghalaya.
  • Recording the connection between winter rainfall amounts in northeast India and climatic conditions in the Pacific Ocean.

Summer Monsoon and EL Nino Connection

  • India՚s summer monsoon (June to September) .
  • Brings in about 70 % of annual rainfall in the country.
  • Known to be heavily influenced by the variability in sea-surface temperatures of Pacific Ocean.
  • A condition referred to as El Nino Southern Oscillation (ENSO) .

Significance

  • North-eastern monsoon is important for several regions in the Northeast and India՚s eastern coast.
  • Winter rainfall can alleviate water stress for farmers.
  • Study could help in predicting the winter rainfall and prepare for rainfall variations.
  • Vital to understanding past variability in the global climate system.

- Published/Last Modified on: March 28, 2020

Geography

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