Lab 1 Flashcards
1
Q
Epilimnion
A
- The upper layer of water in a stratified lake
- Usually the warmest water
- Constantly circulating
2
Q
Metalimnion
A
- The middle layer of water in a stratified lake
- Includes the thermocline
- Provides a barrier to water circulation for the hypolimnion
- Area of rapidly decreasing temperature
- Periodically mixes
3
Q
Hypolimnion
A
- The bottom layer of water in a stratified lake
- Cold and relatively undisturbed
- Rarely mixes
4
Q
Dimictic Lake
A
- Lake that mixes twice a year
5
Q
Polymictic Lake
A
- Lake that mixes more than twice a year
6
Q
Relative Thermal Resistance (RTR)
A
- Relative thermal resistance to mixing
- The energy required to mix water at two different densities
- Comparisons made between the difference in the density of water at 4 °C and 5 °C.
- Assesses strength of the density stratification
- Energy is usually wind
7
Q
Thermal Stability (S)
A
- This is the inertial resistance to complete mixing caused by differences in vertical density gradient
- Amount of work required to fully destratify a lake instantaneously, without having to consider the addition or removal of heat required over time
8
Q
Chemical Stratification
A
- Stratification of lakes due to different elements and compounds in the water at different depths
9
Q
Internal Seiche
A
- Mixes the water in a thermally stratified lake
- Only occurs in lakes that are stratified
- The water oscillates along the metalimnion
- Causes turbulence on the thermocline
- Breaks up the density differences
10
Q
Surface Seiche
A
- Mixes the water in a thermally stratified lake
- Happens on the surface, winds move water to one side of the lakes causing upwelling
- Causes turbulence on the thermocline
- Results in a surface push - one side of the lake will have a higher water level
- It oscillated back and forth
11
Q
Summer Heat Income
A
- Amount of heat required to heat the lake from spring mixing to is maximum heat income
12
Q
Temperate Dimictic Lake
A
- Mixes seasonally
13
Q
Temperate Meromictic Lake
A
- Mixes seasonally, but not to the bottom
2. Chemical and temperature gradient present
14
Q
Tropical Lake
A
- Seasonality is less distinct
15
Q
Gentian Violet
A
- A purple coloured dye
- It remained mainly in the epilimnion in Lab 1, curving when in a different temperature (indicating a density change due to changing temperatures)
