130 likes | 366 Views
Freshwater. Lake Classification. Trophic system Eutrophic Mesotrophic Oligotrophic Dystrophic More Fish, size, closed or fed, etc. Freshwater Chemistry. Total amount of ions called TDS Cations Ca+2 63% Mg+2 17% Na+ 15% K+ 4%
E N D
Lake Classification • Trophic system • Eutrophic • Mesotrophic • Oligotrophic • Dystrophic • More • Fish, size, closed or fed, etc.
Freshwater Chemistry • Total amount of ions called TDS • Cations • Ca+2 63% • Mg+2 17% • Na+ 15% • K+ 4% • When Ca and Mg is high called hardwater lake due to high buffering capacity called softwater when low • The low calcium within Lake Superior is making it more resistant to zebra mussel invasion
Freshwater Chemistry • Anions • HCO3- 73% • SO4-2 16% • Cl- 10% • Best understood ion is hydrogen ion due to it determining pH • Average lake pH is about 7.2 • Average lake pH is about 7.4
Acid • Acid • Caused by the excessive amounts of sulfur and nitrogen released by cars, industrial processes, or volcanoes • Dry-sticks to dust or stays around with smoke • Wet-any form which removes the acid from the surface and deposits it on Earth’s surface • Kills many smaller fish and eggs in lakes due to them not being able to tolerate large differences in pH • Mercury can also be carried in acid rain and be transferred to fish crating the possibility of mercury poisoning
Lake Physical Properties • Can become salt water if it has no way no remove water • Water carries minerals • Nothing carries minerals away • 98% of all accessible surface water is contained in lakes • Due to solid form of water being less dense whole lakes won’t freeze solid
Our effect on Lakes • Valuable to us for • Trade routes • Irrigation • Drinking water • Climatic control • Hydro-electric energy • Pollution • Point- able to trace back to origins • Nonpoint- not able to trace back to origins
Human impact on lakes • Damming • Downstream destruction • Upstream flooding • Invasive species • Disrupts local ecology • Pollution • Kills organisms
River geography • Most sediment deposition occurs in plains • Most have a delta at the end of the river where the river sriversplits into many channels and deposit sediment • The goal of the river is to create a wide flat valley to flow to the ocean • When a river meets the ocean or sea they form estuaries • Meanders are constant bends in rivers
Human impact on rivers • Levees • The flooding of plains deposit nutrients which allow flood plains to flourish • Levees prevent these flood plains from receiving their nutrients • Levees also cause the flooding to happen somewhere else either up or downstream • Pollution • Rivers are also effected by point and non-point pollution • Though much of the pollution is downstream rather then upstream
Groundwater • http://earthguide.ucsd.edu/earthguide/diagrams/groundwater/index.html • Overuse of groundwater is called overdraft • Problem in arid areas for running out of water • Also problem in hyporheic zones • Pollution • Very susceptible to pollution • Subsidence • The deflation of land due to the decrease of hydraulic pressure underground
Icebergs and sea ice • An iceberg is a floating piece of ice which has broken or calved off of a glacier • An iceberg has 90% of it’s mass underwater • Ice types • Pancake ice- round slushy ice which is 30cm to 3m in diameter • Brash ice- accumulation of floating ice no more then 2m across, wreckage of other ice • Ice cake- any flat piece of ice less then 20m across • Polynya- an area of open ocean surrounded by sea ice
Sea ice • Grease ice- very thin soupy layer of clumped frazil ice • Frazil ice- a collection of loose needlelike ice • Fast ice- ice which forms and is attached to the coast • Ice floe-any flat piece of ice 20m or more across • Small 20-100m • Medium 100-500m • Big 500-2000m • Vast 2-10km • Giant >10km