Key Concepts & Self-Assessment20 Key Facts
Review key The Cryosphere: Polar Ice, Glaciers & Permafrost exam facts and rate your mastery to track revision.
Progress: 0/20 Rated 0 Mastered 0 Review Later
#1
The cryosphere encompasses all regions of Earth where water exists in solid form, including ice sheets, glaciers, sea ice, snow cover, lake ice, river ice, and permafrost.
#2
The term cryosphere originates from the ancient Greek word kryos, which translates to icy cold, frost, or chill.
#3
The cryosphere contains roughly seventy-five percent of the world's freshwater resources, primarily locked within polar ice sheets.
#4
Antarctica and Greenland host Earth's two continental ice sheets, together holding more than ninety-nine percent of all freshwater ice on the planet.
#5
If the entire Antarctic ice sheet melted, global mean sea levels would rise by approximately fifty-eight metres.
#6
The Hindu Kush Himalayan and Tibetan Plateau region is termed the Third Pole or the Water Tower of Asia because it holds the largest ice volume outside the polar zones.
#7
Ten major Asian river basins, including the Indus, Ganga, Brahmaputra, Yangtze, and Mekong, depend on meltwater discharges from the Himalayan cryosphere.
#8
Sea ice forms from ocean water and floats on the marine surface, rejecting salt into surrounding waters through brine expulsion during freezing.
#9
Melting sea ice does not directly increase global sea level because the ice is already floating and displacing ocean water according to Archimedes' principle.
#10
Terrestrial snow cover exhibits the greatest seasonal variation among all cryospheric elements, covering up to forty-seven million square kilometres of the Northern Hemisphere in winter.
#11
Fresh snow displays an exceptionally high albedo, reflecting up to eighty-five to ninety percent of incoming solar radiation back into space.
#12
The ice-albedo feedback is a positive feedback mechanism where declining ice cover reduces planetary reflectivity, leading to increased heat absorption and accelerated melting.
#13
Permafrost is defined as ground, sediment, or rock that remains at or below zero degrees Celsius continuously for at least two consecutive years.
#14
The active layer is the uppermost layer of permafrost ground that thaws during summer and freezes again during winter.
#15
Thawing permafrost destabilizes sub-polar infrastructure and exposes centuries-old preserved organic matter to microbial decomposition, releasing methane and carbon dioxide.
#16
Thermokarst refers to irregular, pitted terrain characterized by sinkholes, subsidence depressions, and collapse lakes created when ice-rich permafrost thaws.
#17
Lake and river ice seasonal duration has shortened globally over recent decades, altering freshwater ecology, winter transport corridors, and spring flood timings.
#18
India coordinates its polar and high-altitude cryosphere research through the National Centre for Polar and Ocean Research (NCPOR), an autonomous institute based in Goa.
#19
India operates active Antarctic research stations named Maitri (established 1989) and Bharati (commissioned 2012), following its initial station Dakshin Gangotri (1983).
#20
In the Arctic, India established its Himadri research station in 2008 at Ny-Ă…lesund in the Svalbard archipelago of Norway to investigate oceanic and atmospheric cryospheric linkages.
Subject Specialist Commentary
Analytical perspective & practical exam advice from the Master10 academic board
The cryosphere is Earth's frozen domain, containing everything from continental ice sheets and mountain glaciers to floating sea ice, winter snow, and subterranean permafrost. It regulates planetary temperatures by reflecting solar radiation back into space through high surface albedo. When solid ice melts into liquid water, solar reflectivity drops sharply, transforming heat-reflecting surfaces into heat-absorbing zones.
For competitive examinations like UPSC and State PSCs, focus on the distinction between land ice and sea ice. Remember that melting ice sheets and mountain glaciers cause direct sea level rise, while melting floating sea ice does not directly raise ocean volume. Watch out for questions confusing permafrost with seasonal frost; permafrost requires ground to stay at or below zero degrees Celsius for at least two consecutive years. Use the mnemonic "S-P-I-C-E" (Snow, Permafrost, Ice sheets, Currents/sea ice, Elevation glaciers) to recall the major cryospheric components.
Related Knowledge Topics to Discover
Looking for more GK practice?
Explore 52,789+ questions across 65 General Knowledge categories.