BIOL-208 Lecture 3: Chapter 3 Lecture
17 Dec 2016
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Chapter 3
- Hydrologic cycle
- Where water is and how it moves
- More than 71% of earth’s surface covered by water
- oceans: 97% of the total 71%
- Polar ice caps and glaciers: 2%
- Freshwater in lakes, streams, and ground water make up less than 1%
- 20% of the world’s freshwater is in Canada
- NAFTA and selling of water
- Mostly deep underground and can’t be accessed
- Distribution of water is dynamic
- Heat
- Clouds and contaminants
- Precipitation
- Evaporation and evapotranspiration
- Plants often do both at the same time
- Consumed by organisms
- Groundwater
- Surface water
- Turnover: time required for entire volume (reservoir) to be renewed
- Atmosphere: 9 days
- Rivers: 12 to 20 days
- Lakes: days to centuries
- Oceans: 3100 years
- Contaminants will remain for long time in lakes
- Natural history of aquatic environments
- Oceanic cycling
- Wind creates gyres
- Coriolis effects
- Oceans
- Geography
- Undersea trenches: marianas trench in western pacific ocean is
10000m deep, so deep, it would engulf mount everest with 2 km
left
- Pacific
- 4000m average depth
- 1000m average depth
- Approximately 180 million km2
- Gulf of California, Gulf of Alaska, Bering Sea, Sea of
Okhotsk, Sea of Japan, China Sea, Tasman Sea, Coral
Sea
- Atlantic
- 3500m average depth
- More than 106 million km2
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- Mediterranean, Black Sea, North Sea, Baltic Sea, Gulf of
Mexico, Caribbean Sea
- Arctic
- Less than 14 million km2
- Barents Sea, Beaufort Sea, Greenland Sea, Hudson Bay,
Baffin Bay
- Structure
- Littoral zone
- Intertidal zone, shallow shoreline
- Neritic zone
- Coast to margin of continental shelf
- Up to 200m deep
- Humans do a lot of fishing and harvesting
- Epipelagic zone: 0 to 200m
- Mesopelagic: 200 to 1000m
- Bathypelagic: 1000 to 4000m
- Abyssal: 4000 to 6000m
- Hadal: more than 6000m
- Benthic: habitat on bottom of ocean
- Pelagic: habitat off the bottom of the ocean
- Physical
- Light
- 80% of solar energy is absorbed in first 10 m, producing
world’s 25% productivity
- Very little penetrates past 600m
- Leaves 3400m of deep, black water
- Temperature
- Increases velocity of water molecules
- Decreases density, so warm water is on top of cool
- Thermocline
- Temperature changes rapidly with depth
- Causes thermal stratification
- Movement
- Always moving
- Wind creates gyres
- Deepwater currents cause upwellings
- Chemistry
- Salinity
- Open ocean: 34 parts per tonne to 36.5 parts per tonne
- Less near equator: precipitation greater than evaporation;
salt is diluted because of the rain
- More in subtropics because evaporation is greater than
precipitation; salt is deposited and concentrates as water
evaporates
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Document Summary
Where water is and how it moves. More than 71% of earth"s surface covered by water. Freshwater in lakes, streams, and ground water make up less than 1% 20% of the world"s freshwater is in canada. Mostly deep underground and can"t be accessed. Plants often do both at the same time. Turnover: time required for entire volume (reservoir) to be renewed. Contaminants will remain for long time in lakes. Undersea trenches: marianas trench in western pacific ocean is. 10000m deep, so deep, it would engulf mount everest with 2 km left. Gulf of california, gulf of alaska, bering sea, sea of. Okhotsk, sea of japan, china sea, tasman sea, coral. Mediterranean, black sea, north sea, baltic sea, gulf of. Barents sea, beaufort sea, greenland sea, hudson bay, Humans do a lot of fishing and harvesting. Pelagic: habitat off the bottom of the ocean. 80% of solar energy is absorbed in first 10 m, producing world"s 25% productivity.
