Stratification II

Question 1

Not all lakes stratify equally (even in the same climate). What are two main reasons for this?

Answer 1

1. Lake color (transparency): changes light penetration depth (clearer lakes= deeper epilimnions)
2. lake size

Question 2

Deeper lake are ___(more/less) likely to stratify

Larger lakes “ “

Answer 2

deeper= more likely (b/c allows denser water to sink to depth)

larger= less likely to stratify and will have deeper thermoclines

Question 3

Most absorbed solar radiation converts into ___ in surface waters, which is then mixed down by ____

Answer 3

heat
turbulence

Question 4

Warming of the lake surface is pronounced in brownish lakes, resulting in more ____ and ___ thermoclines

Answer 4

shallow and stable

Question 5

Thermoclines tend to be relatively ___ and ___ in clear lakes

Answer 5

deep and weak

Question 6

___ is a key determinant of the magnitude of surface waves and ability of wind action to mix to depth

Answer 6

fetch

Question 7

larger lakes have longer fetch distances, causing the thermocline to be _________(deeper/ shallower)

Answer 7

deeper

Question 8

t/f
wind exposure can lead to an early onset of ice cover

Answer 8

false
later onset because of mixing

Question 9

smaller, irregularly-shaped lakes stratify quickly in the spring, so a _____(greater/weaker) temp gradient develops within the metalimnion

Answer 9

greater

Question 10

T/F
Fetch affects the stability of the metalimnion

Answer 10

true

more fetch= more poorly defined metalimnion

Question 11

The degree of mixis within a lake depends on:
1
2

Answer 11

climate (latitude) and lake depth

Question 12

T/F
The compensation depth does not necessarily happen in the metalimnion

Answer 12

true