alleryStart learning →What does the residence time of a water molecule measure?
AAverage time spent in one reservoir
BAverage speed through the whole cycle
CAverage distance covered each year
DAverage depth reached in the ocean
Answer & Solution
Correct answer: A. Average time spent in one reservoir
1. Water is stored in reservoirs such as oceans, ice, groundwater and the atmosphere.
2. Residence time is the average time a molecule stays in one of those reservoirs.
3. Water locked in ice or deep underground has a very long residence time.
4. Only surface water can evaporate, so most of the store is unavailable for short term cycling.
_Source: OpenStax Biology 1e (CC BY 4.0), Chs 44 and 46, section 46.3 Biogeochemical Cycles_
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