Lecture 7a Flashcards
Standing Waters: Concepts (Lake)
Is a large or considerable body of standing water either salt of fresh water surrounded by land
Standing Waters: Concepts (Shallow Lake)
Is a large body of water easily mixed to the bottom by casual winds
Standing Waters: Concepts (Pond)
Is a small and shallow body of water where light penetrates to the bottom
Standing Waters: Concepts (wetland (mire))
Is a body of water where vegetation protrudes from water surface (water table at/near land surface)
Standing Waters: Concepts (What encompasses a Wetland (4))
- Bog
- Fen
- Marsh
- Swamp
What is a Bog:
A peatland with acidic peat (un-decomposed organic matter) and nutrient poor (ombrotrophic: rainwater)
What is a Fen?
Is a peatland that is neutral/alkaline fed by nutrient poor mineral-rich surface or ground water +/- tall plants (trees)
What is a Marsh?
Is a nutrient rich wetland with emergents (no trees)
What is a Swamp?
Is a waterlogged wetland with conifers/deciduous
11 Categories of Lakes:
- Tectonic activities
- Volcanic activities
- Landslides
- Glacial, nival activities, permafrost and ice
- Karstic events and solution
- Fluvial lakes, lakes in floodplains and deltaic areas
- Costal Lakes
- Deflation Lakes
- Plant accumulations and animale (raised peat bogs, beavers)
- Artifical lakes
- Meteoric impacts
- Tectonic Activity Lakes
- Graben Lake
- Rift Lake
- Volcanic Activity Lakes:
Flooded crater Lakes
- Landslide Lakes:
In between mountain ranges
- Glacial, Nival (snow), Ice, and Permafrost Lakes:
- Alpine Lake Basins
- Morains as Dams
- Proglacial Lake
- Fluvioglacial Plain Lakes
- Plonge Pool Lake
- Glacier Scour Lake
- Patterned Ground Lake
- Great Lake Formation
- Karstic events and solution
Sinkhole Lakes (temperate and tropical)
- Fluvial lakes, lakes in floodplains and deltaic areas
Fluvial Lakes
- Coastal Lakes
Lakes near the shoreline of the ocean
- Deflation Lakes
- Plant Accumulation and Animal Lakes
Lakes made by animals like beavers after putting in dams in rivers/creeks
Leads to a large accumulation of biodiversity in the lake
- Artificial Lakes and Reservoirs
- Drinking water
- Irrigation
- Retention
- Mills
- Fish ponds
- Strip Mining
- Defense and war
- Fire/Ice/Farm ponds
- Hydroelectiric Power Reservoirs
- Recreation
- Purification
- Meteoric Impact Lakes
Formed where large meteors hit the Earth’s surface and formed a basin
Lake Have Vertical Structure due to:
- Stratification
- Thermal Stratification
- Lake Mixing
What is Stratification?
Structuring of water body into layers due to physical, chemical, biological inputs and processes
What is Thermal Stratification?
Varies by latitude and climate due to different thermal inputs including wind feilds
What is Lake Mixing?
Is caused by energy inputs in a balance between buoyancy and inertia. There are seasonal mixing patterns caused by a variety of energy inputs
Lake Structure (1. Morphometry)
Basin shape (irregular, dendritic, rounded to DL)
Lake Structure (2. Hydrology)
Retention time goes to chemical properties
Lake Structure (3. Light)
Compensation depth
1. Littoral
2. Limnetic zones
3. Profoundal zones
Lake Structure (4. Heat)
Stratification vs. mixing leads to biology/chemistry
1. Epilimnion
2. Metalimnion
3. Hypolimnion
Lake Structure (5. Turbulence)
Lake mixing, sediment stability/mobility in littoral
What can Lead to Stratification?
Thermal inputs and lack of mixing
What Does Stratification Indicate?
The presence of layer of different density conditions. The less dense water has higher buoyancy and floats on more dense water
What Determines if Different Densities Arise? (stratification)
This is due to temperature and also chemistry
When does Mixing Occur During Stratification
When mixing overwhelms the buoyancy
7 Mixing Patterns in Lakes:
- Diel/episodic
- Dimictic
- Monomictic
- Amictic
- Polymictic
- Holomictic
- Meromictic
Stratification/Mixing Patterns (1. Diel/episodic)
Diurnal mixing
Stratification/Mixing Patterns (2. Dimictic)
(2/yr) Spring and fall mixing
Stratification/Mixing Patterns (3. Monomictic)
(1/yr) Fall mixing
Stratification/Mixing Patterns (4. Amictic)
(0/yr) No Mixing
Stratification/Mixing Patterns (5. Polymictic)
(>2/yr) Small, shallow lakes
Stratification/Mixing Patterns (6. Holomictic)
Entire lake mixes
Stratification/Mixing Patterns (7. Meromictic)
Deep layer of non-mixing water
Lake Structure - Mixing (Energy Inputs)
- Solar
- Wind stress
- Density Gradients
Littoral/Limnetic Zones Receives/Responds Considerable Energy (3)
- Thermal
- Wind
- Density Interactions
Littoral/Limnetic Zones Receives/Responds Considerable Energy (1. Thermal)
Heating, convection, precipitation, evaporation, rivers, groundwater
Littoral/Limnetic Zones Receives/Responds Considerable Energy (2. Wind)
Creates water, stokes drift, seiches, horizontal mixing, Langmuir cells
Littoral/Limnetic Zones Receives/Responds Considerable Energy (3. Density Interactions)
- Stratification, instabilities, pumping, cooling, rivers
- Morphometry is also important
