EXAM 1

Question 1

Characteristics of a lake

Answer 1

size based definitions: surface area, depth or zonation

Question 2

Glacial lakes

Answer 2

74% of lakes, nutrient rich. formed from ice barriers or glacial erosion. Continental glaciers moved rocks and sediment to change the landscape.

Question 3

Tectonic lakes

Answer 3

~5% of lakes. Often U or V shaped basins. Deep and unproductive. have GRABENS: flat bottom valleys produced by tectonic plate activity

Question 4

Volcanogenic lakes

Answer 4

«1% of lakes. low nutrient concentrations and unproductive. deep usually old

Question 5

Karst Regions

Answer 5

Lakes formed by soluable rocks (limestone or dolomite) that dissolves with acidic water. Small and unevenly distributed around the world

Question 6

Riverine lakes

Answer 6

oxbow lakes: form when bends in a river become isolated due to errosive forces of rivers, usually shallow and oddly shaped

Question 7

Floodplain lakes

Answer 7

form due to seasonal fluxes in water levels in a river basin

Question 8

littoral zone

Answer 8

margin of lake to depth where no plants can grow

Question 9

limnetic zone (palagic zone)

Answer 9

open water, no shore visible

Question 10

benthic zone

Answer 10

bottom zone associated with sediments

Question 11

profundal zone

Answer 11

deep region of the benthic, no light, fine sediments

Question 12

limnetic zone

Answer 12

photic zone

Question 13

profundal zone

Answer 13

aphotic zone

Question 14

Epilimnion

Answer 14

top layer, warmer and lighter

Question 15

Metamnion

Answer 15

medium temperature medium light

Question 16

hypolimnion

Answer 16

dark, cold

Question 17

meromictic lake

Answer 17

so deep that there is no single temperature, layer at the bottom never mixes

Question 18

dimictic

Answer 18

2 mixing events per year

Question 19

monomictic

Answer 19

mixes once a year

Question 20

what enables mixing?

Answer 20

shallow waters, large fetch, lack of ice cover, lack of sheltering topography, large meteorological events (hurricanes)

Question 21

catchment

Answer 21

area of land that drains into an aquatic system

Question 22

seepage lakes

Answer 22

isolated. no inlets or outlets

Question 23

drainage lakes

Answer 23

connected, inlets and outlet streams

Question 24

lowland drainage lakes

Answer 24

connected, have inlets and outlets

Question 25

drained lakes

Answer 25

no inlet streams. have an outlet

Question 26

terminal lakes

Answer 26

has an inlet with no outlet

Question 27

oligotrophic

Answer 27

little nutrients and phytoplankton

Question 28

mesotrophic

Answer 28

some algae in late summer, shallow plants, some sediment buildup

Question 29

eutrophic

Answer 29

lots of nutrients and phytoplankton, lots of chlorophyll a making it green, shallow

Question 30

Trophic state index (TSI) based on what perameters

Answer 30

water clarity, chlorphyll a, total nitrogen, total phosphorus

Question 31

water year

Answer 31

October 1-September 30

Question 32

recharge lakes

Answer 32

lakes that are above the water table

Question 33

flow-through lakes

Answer 33

lakes that receive and discharge groundwater

Question 34

discharge lakes

Answer 34

lakes that are below the water table, only groundwater is their input

Question 35

closed basin lakes

Answer 35

endoheric, no surface flows, long residence times

Question 36

open basin lakes

Answer 36

exorheric, surface outflows, evaporation

Question 37

el nino southern oscillation

Answer 37

last 9 months to two years, occurs every 3-7 years

Question 38

Morphometry

Answer 38

quantifies the size, shape, and physical dimensions of a lake

Question 39

What types of lakes are circular

Answer 39

caldera

Question 40

what types of lakes are lunate

Answer 40

oxbow shape formed from river bends

Question 41

what types of lakes are dendrictic

Answer 41

most commonly formed from dammed rivers

Question 42

Bathymetric Map

Answer 42

Shows underwater topography using contours of equal depth (isobaths) Historically created by sounding using a weighted line lowered until it hit the bottom

Question 43

Modern methods for creating bathymetric map

Answer 43

echo sounding GPS, side scan sonar, dropping the boat into a large body of water

Question 44

Shoreline development index

Answer 44

a measure of how complex the shoreline of a lake is relative to expected if the lake was a perfect circle D= 1 means the lake is a perfect circle

Question 45

Fetch

Answer 45

Simplest measure of fetch is the longest possible distance across which wind can blow This can be expanded to effective fetch, which adds in the relative direction of dominant winds a lake experiences Fetch influences wave action, which influences bottom sediment mixing in lakes, which influences the depth of the thermocline and epilimnion in lakes`

Question 46

Sieche

Answer 46

is a standing wave and in an enclosed body of water