BharatNotes Esker
noun (countable)Usage in a UPSC answer
The discovery of esker systems beneath Greenland's ice sheet by radar surveys suggests that sub-glacial meltwater drainage networks are more extensive than previously modelled, with significant implications for ice-sheet stability projections.
Synonyms
Antonyms
Word Family
esker (noun), eskerian (adjective, rare), esker system (compound noun)
Root
Irish eiscir = ridge, gravel ridge; Old Irish escir; the same root gives the Eiscir Riada, an ancient esker road across Ireland
Etymology
Borrowed into English geological literature from Irish eiscir (a ridge, specifically a gravel ridge), first recorded in English around 1833 during geological mapping of Ireland. The term was popularised by Irish geologist Richard Griffith in the early 19th century. The Eiscir Riada, a chain of eskers crossing Ireland from Dublin to Galway, was historically used as a major overland route, illustrating the practical importance of these landforms.
Memory Hook
An ESKER is like the SKELETON of a glacial river — after the ice and water are gone, the sandy ridge of sediment remains, winding across the landscape like a long spine or backbone.
How This Word Works in UPSC Writing
A long sinuous ridge of sand and gravel deposited by a meltwater stream flowing within or beneath a glacier. Its interest for GS1 is that it is a fluvioglacial rather than purely glacial landform, recording the drainage of water through the ice, and its winding course cutting across slopes is the giveaway that ice, not gravity, confined the channel.
Don’t Confuse It With
An esker is a sinuous fluvioglacial ridge laid by meltwater in an ice tunnel. A kame is a mound of stratified meltwater sediment. An outwash plain is the sheet of sediment deposited beyond the ice margin. A moraine is unsorted till deposited directly by ice rather than by water.
Hindi Meaning
एस्कर (eskar), used as a loanword; हिमनदीय जलोढ़ कटक descriptively.
Common Questions
- What is an esker?
- A long winding ridge of sand and gravel deposited by a meltwater stream flowing in a tunnel within or beneath a glacier.
- Why are eskers described as fluvioglacial?
- Because they are laid down by meltwater rather than directly by ice, which is why they are sorted and stratified rather than unsorted like till.
Tip: press Alt+S to hear pronunciation
