ST final exam Flashcards
(15 cards)
what is permafrost?
a layer of permanently frozen soil (0 degrees or lower for at least 2 years)
list 3 effects of global warming on permafrost
- softening of the soil which can cause damage to infrastrucutre by destabilizing the foundation
- landslides
- methane and CO2 trapped underneath permafrost can be released
what is a catchment area?
a territory surrounding a waterway
a catchment area is AKA an
area of land, marked off by natural boundaries, in which all the surface runoff and groundwater drains into the same place
what is salinity
a measure of the quantity of salt in a solution
what is energy efficiency of a device or system
the proportion of energy consumed that is transformed into effective work
explain guiding
it is the function performed by a component that controls the motion of a moving component so that it allows a specific trajectory
what is the power supply
the ability to provide an electrical current
what is conduction
the ability to conduct electricity
what is control
the ability to control the travel of electrical current
what is a constraint
an external force that is exerted on materials and that has a tendency to deform them
what is the difference between glaciers and pack ice?
- glaciers is a mass of freshwater ice on land while pack ice is frozen seawater (brackish=freshwater and seawater) floating on oceans near the North and South poles
- glaciers cause and increase in sea level while pack ice causes no change in sea level
- glaciers are MELTING due to global warming while pack ice are currently WARMING due to global warming
what happens when glaciers melt?
- freshwater from them flow down its watershed into the ocean, adding to the volume of ocean water
- it also dilutes the saltwater, decreasing the salinity and therefore affecting the thermohaline circulation
what happens when pack ice melts?
it does not add volume but does change salinity
