WCC: Water Cycle - Global Distribution of Water Stores Flashcards
Where is cryospheric water stored?
Ice caps, permafrost, alpine glaciers, sea ice, ice sheets
Where is terrestrial water stored?
Surface water (wetlands, rivers, lakes), groundwater, biological water, soil water
Example of sea ice
Ross Ice Shelf
Example of ice caps
Icelandic ice cap
Example of ice sheets
Greenland ice sheet
Example of alpine glaciers
Mer de Glace, France
Example of permafrost
Alaska North Slope
Does sea ice raise the sea level when it melts?
No as it forms from ocean water
Which 2 ice sheets contain more than 99% of the freshwater on Earth?
Antarctic and Greenland ice sheets
How big is the Antarctic ice sheet?
14 million km^2, covering an area roughly the size of Mexico and the USA combined
How much would sea levels rise if the Greenland ice sheet melted and if the Antarctic ice sheet melted?
Greenland ice sheet - 6m
Antarctic ice sheet - 60m
Where are ice caps usually found?
Mountainous areas such as the Himalayas, the Rockies, the Andes and the Southern Alps of New Zealand
How much does the thickness of permafrost vary?
From 1m to over 1500m
How much of the Earth’s surface does permafrost cover?
Around 1/4, including vast areas of Northern Canada, Alaska and Siberia
What allows the ocean to stay as liquid water below 0C
Dissolved salts
What is the pH of the oceans?
8.4 - alkaline
Why is the pH of oceans steadily falling?
An increase in atmospheric carbon
What is the largest lake? What is its area?
The Caspian Sea at 78,000km^2
What is the deepest lake? Give data to support this
Lake Baikal in Siberia, mean depth 749m, deepest point 1637m
Global distribution of wetlands
Wetlands are found in every continent except Antarctica
What is the world’s largest freshwater wetland system?
the Pantanal of South America
How does the Pantanal provide economic benefits to South America?
It’s a huge area for water purification, climate stabilisation, water supply, flood abatement, and provides an extensive transport system
What ecosystem covers nearly 60% of the Arctic?
Wetlands
Where do aquifers most commonly form?
In rocks such as chalk and sandstone, which are porous and permeable
What is the water table?
The depth at which rock becomes completely saturated with water
What changes the level of the water table?
Groundwater flow, abstraction by people or recharge
What can soil water impact?
Weather and climate, run-off potential, flood control, oil erosion, reservoir management and water quality
Why is it dry over the poles and humid over the tropics?
Because cold air cannot hold as much water vapour
What are aquifers?
Vast underground reservoirs formed by water stored in rocks deep below the ground surface
Through which soil types is water easily transferred and through which soil types is it had for water to be transferred?
Easy - porous, sandy soils
Hard - clay
What is the water budget?
Soils capacity to store and transfer water
What are aquifers in the deserts called?
Fossil aquifers
Where do saline aquifers exist?
Where seawater had infiltrated into the rocks, often due to over-abstraction
What can shortages of water lead to?
Migration and famine
Name the 4 main physical systems that store water.
Atmosphere
Cryosphere
Hydrosphere
Lithosphere
Rank these 9 water stores by size: Rivers Soil water Atmosphere Oceans Living things Glaciers, ice caps, ice-sheets Swamps, marshes Lakes Groundwater
- Oceans
- Glaciers, ice caps, ice-sheets
- Groundwater
- Lakes
- Soil water
- Atmosphere
- Swamps, marshes
- Rivers
- Living things
What percentage of global water is saline water?
97.4%
Where is the majority of saline water stored?
Oceans
What percentage of global water is freshwater?
2.5%
What kind of water is needed to sustain life?
Freshwater
What percentage of freshwater is stored in the glaciers, ice caps and ice-sheets?
68.7%
What percentage of freshwater is stored as groundwater in aquifers?
30.1%
What percentage of freshwater is stored as surface water?
1.2%