Exam I

photic zone

levels and isobars

elevation contours of a lake

longest point

langest point perpedicular to max length

Zmax

Zmean

depth verse area plot

• volume esitmate
• water reulation
• zmean

• Precip/evaporation
• inlets/outlets
• groundwater

open basin

closed basin

depends on V, climate, Zmean, ratio of catchment to lake area

increase chemical storage

less nutrient loading

water loss from other lakes (splitting)

Glacial scour lakes

• emtamorphic rock formed from heating and pressurizing clay
• more easily eroded than diabase

very hard igneous rock

• bathymetry
• south

• increased visit by humans
• increased stream connections

• industry- managed for aquaculture
• acedemic- chronosequence for community assemblege
• recreation/property developement

• volume
• inputs/outputs
• flushing rate
• volume in contact with sediment
• nutrients and gases
• organisms and metabolism

• environemtal force
• terrain reshape into depression
• water source

excavation of a basin from glacial movement

ice scour lake on alpine slope

construction of a rim through pushing and deposition of glacially moved sediments

formed when a peice of ice break free from a glacier and gets left behind

proglacial type formed when glacial meltwater ponds in front of a glacier

large scale movemnt of earths crust creates cracking and depression

tilting, sinking, or rising of the earths crust to affect drainage area

eruption crates basin due to loss of debris

sediment erosion and deposition on a river bank that isolates a merandering arm

3.94 C

• mixing layer
• smallest slope

• spring-even
• summer- stratified
• fall-even
• winter- inverted stratification

• isothermal
• oxygen and nutrients disturbed
• temperatures trigger dormant egg release

• days lengthen
• sun angles more direct
• air temp rises

• resists mixing
• barrier to mixing
• epilimnion thickens
• hypolimnion temp = spring overturn

• days shorten
• sun is less direct
• air temp falls

• wind mixes water column
• isotherm
• distributes nutrients and oxygen

inverse stratification

• 1 circulation every year (summer)
• small arctic lakes

• stratified only in summer, mixes rest of the year
• lake superior

• two distincnt circulation events per year
• most common lakes

many circulation events per year\shallow and wind exposed

• incomplete mixing
• deepwater salt concentration
• increase in density

mixes annulaly

doesn't mix

total heat flux

radiation

conduction

inlets and outlets

evaporation and melting

winter heat

• m-2 sec-1
• 1 joule = 0.24 calories.

• m-2 sec-1
• where 1 Einstein = 1 mole of photons.

determines color and energy

by Planck’s constant (Energy = h * frequency)

strongest amount of light

water scatters according to (1/wavelength)^4

k (measure of light attenuated).

inversely

depth of 1% surface light

• use k = (ln I0 – ln Iz) / z
• set I0 = 100% and Iz = 1 %, then
• Zphotic = ln 100/k

less pennetration

Mixing depth where phytoplankton depth-integrated photosynthesis = depth-integrated respiration.

• pressure
• salinity
• temperature

low solubility

low solubility

low solubility

• atmospheric diffusion
• photosynthesis
• metabolism of bacterium

increasing oxygen with depth

decreasing oxygen with depth

increase in oxygen at mixing layer

decrease in oxygen at mixing layer

• small size
• reduced movement
• increase gill to vein factor
• gulp air bubbles

area of circle (pi rsquared)

• circumfrence of circle
• 2pi r

• (area of shallow + area of deeper)/2 * depth between planes
• then sum all levels

Depth vs Area

V/A

• less than 5meters
• (surface area - area of 5m plane)/ surface area

248.313*Zmean(m)6^-1.552

volume/losses