lecture #1

Question 1

What is lake morphology?

Answer 1

The physical shape of lakes

Question 2

What is lake morphometry?

Answer 2

measurement of the shape of lakes

Question 3

What is lake morphology determined by? What does it effect?

Answer 3

The origin of the lake, this effects physical, chemical and biological parameters of the lake

Question 4

What are the six different types of lake origins?

Answer 4

glacial
riverine
tectonic
coastal
volcanic
other (damning, landslide, earthquake, sinkhole, runoff)

Question 5

What are the physical, chemical, and biological characteristics of volcanic lakes?

Answer 5

Has low productivity (not much nutrients draining in it so nutrients is not coming)
Has high water temp- limits productivity
has low DO due to high elevation

Question 6

How do glacial lakes arise?

Answer 6

As the ice depletes scouring occurs, this causes depressions and water resides in them.

Question 7

If lakes are near one another are they likely to have the same origin?

Answer 7

yes

Question 8

What does surface area influence?

Answer 8

influences sunlight entering the water column, thermal stratification, evaporation, gas exchange, number of species present and length of food chain

Question 9

What is maximum fetch? What does it influence?

Answer 9

Is the longest stretch upon which wind can blow, influences the effect of wind on the lake, wave height, and shoreline disturbance (is how many waves that come to shoreline causing erosion and moving things around), also thermal stratification.

Question 10

How do we describe length of shoreline?

Answer 10

through the shoreline development index

Question 11

How does the volume of the lake influence it?

Answer 11

this influences how much water and solutes are present, how long the water stays in the lake, and the importance of sediment water interactions

Question 12

What is maximum depth? What does it effect?

Answer 12

maximum depth is the deepest point in a lake, affects how much light is getting through and how much oxygen is getting through.

Question 13

What is the mean depth of a lake?

Answer 13

is volume/surface area

Question 14

What pattern is common in size distribution of lakes?

Answer 14

As the frequency of lakes increase the lake area decreases and vice versa.

Question 15

What is the shoreline development index?

Answer 15

It describes the shape of the lakes perimeter, this tells us how close we are from a circle. The closer to 1 we are the more circular we are.

Question 16

What is the littoral area versus the pelagic zone? Both have to with depth?

Answer 16

Is the shallow shoreward region of a lake, less than 6 m deep, it usually has light penetration to the bottom and is often occupied by rooted macrophytes (aquatic plants).
The pelagic zone- depth deeper than littoral zone, is middle of lake

Question 17

What do the different areas of the lake effect?

Answer 17

the vertical thermal structure and then it turn the structure of biota and biotic processes vertically.

Question 18

What are the light zones in the lake? Describe them?

Answer 18

Photic zone- is depth to which light will penetrate
Aphotic zone- is depth to which there is limited light penetration- therefore less primary productivity

Question 19

What is the compensation depth in a lake?

Answer 19

is when photosynthesis is equal to respiration

Question 20

What is the profundal zone?

Answer 20

below thermocline, is where water temp drops rapidly, is deep

Question 21

What are Bathymetric maps?

Answer 21

Is underwater contour maps, contour lines drawn close show that the depth is increasing very quickly, when there’s a lot of space it’s slower. Outerlines are shoreline.

Question 22

What are hypsographic curves?

Answer 22

Are graphs used to provide a visual representation of the relationship between the surface area of a lake basin and it’s depth, volume of a lake can be found by integrating curve

Question 23

What is a cumulative hypsographic curve?

Answer 23

Tells you the portion of lake at what depth relative to the entire lake, so for ex: 50% of lake is at 50% of the total depth

Question 24

What does a hypsographic curve tell us?

Answer 24

Tells us about the shape of the lake and the diff zones.

Question 25

Why are some lakes more susceptible to acidification?

Answer 25

• due to local emissions and winds
• local ground
• size of lake (deeper lake dilutes acidification)
• catchment area (what drains into the lake)
• elevation- higher elevation reduces drainage so lower acidification

Question 26

Why are fish assemblage in different lakes?

Answer 26

for big fishes find them at deeper waters as need more DO and productivity
for small fishes, shallow lakes, this is because top predators not there so the smaller fishies take over