Hydrosphere Flashcards
(33 cards)
What is Earth known as
Pale blue dot - abundance of water
Human civilization arose from water
What are the Physio-chemical properties of water
is a good solvent
has a high heat capacity
has a high heat of vaporization
has a relatively high surface tension
is the only natural substance that expands when freezes
What does water have a good solvent mean?
Polarity makes it a good solvent for salts, ionic compounds, sugars, amino acids
Good medium to carry dissolved nutrients
It is easily polluted
What does it mean if water has a high heat capacity?
The amount of heat needed to raise the temp of 1g of water is 1C
It can absorb large amounts of energy before it gets hot
It can release a large amount of energy when it cools down
Thermohaline Circulation
Global heat transport mechanism
What is a high heat of vaporization?
The amount of energy needed to convert a substance from liquid to gas
Water releases large amounts of heat when vapor condenses
Heat can be stored when not needed (cooling environment) It can be released when needed (warming the environment)
explain water having a relatively high surface tension
Surface tension: a force that holds the surface liquid intact
It gives rise to a unique capillary process in plants (pulling water upward)
Explain water being the only natural substance that expands when it freezes
Water is most dense at ~4C (most mass per unit volume)
At high temp, it expands in a more scattered liquid form,
At low temp, it expands as a stable, crystal structure of ice
Fluctuations in water temp generate fluctuations in density
What is the water cycle
The movement of water between the lithosphere, atmosphere, and hydrosphere, and between organisms and their environments
It is a closed-loop (happens in the bounds of the planet)
What are the driving forces of the water cycle
The sun and heat from the Earth’s core (it causes water to evaporate and the core also influences geothermal or volcanic activities)
What are watersheds
area of land drained by river systems, aka drainage basins
It is like a funnel
It can either flow back or into the ocean or seep underground (groundwater)
Characteristics of groundwater
It flows outward through upward movements by underground pressures, uptake by plants, seepage into rivers, or human interventions to extract groundwater (natural springs, wells, pumping)
Where does our supply of freshwater come from
surface and groundwater
What is water residence time (WRT)
The amount of time a molecule of water stays within a particular stage of the water cycle
WRT depends on mobility: how easily can it move
How can we understand WRT
Greater mobility (flows) means shorter residence time
Water vapor has the shortest WRT
Ice caps have the longest WRT
How does WRT impact pollution
Shorter WRT: pollutants can be flushed out
Longer WRT: pollutants take a longer time to flush out
Is water renewable?
It depends on the course of water and its WRT (it can become unusable when limits of pollution are reached)
What are the human uses of water
Ecological services
Economic services
What are the 2 different human uses of water
Consumptive: Any use in which water is removed and not returned
Nonconsumptive: Any use in which water is either not removed, or only temporarily removed
What are the different consumptive uses of water
Municipal or domestic: Everyday household use
Industrial: Different processes and cooling water
Agricultural: Irrigation (biggest demand in developing countries; diets and lifestyle)
Our lifestyle and diet have a great impact on water
What are the different non-consumptive use of water
Hydropower is the largest nonconsumptive use (energy source with high economic investment)
Water can be diverted to be used to cool industrial machines and then returned (returned water can be much hotter causing thermal shock)
What are the threats to water
Pollution
Nutrient pollution
Biodegradable wastes
Sediments and suspended matter
Thermal pollution (thermal shock)
Heavy metals (Minamita disease)
Saltwater intrusion
Carbon dioxide
Destruction of watersheds
Climate change
How does pollution affect water
Water is vulnerable to pollution easily affecting the quality of water
Changes in the chemical, physical, or biological properties of water caused by humans
Toxic chemicals: Pesticides, Pathogens, and waterborne diseases
How does nutrient pollution affect water
Nitrates and phosphates as common pollutants of marine and freshwater systems
It can come from runoff from human settlements
An abundance of nutrients fertilize algae and aquatic plants that deplete dissolved oxygen
Phytoplankton blooms deplete oxygen
