Hydrosphere 1:Earth’s Oceans

ppt. by Robin D. Seamon1

D I S T R I B U T I O N

• 70 % of Earth’s surface is water• 4 bya water vapor condensed into shallows• 1 big ocean, 5 major basins

• Pacific• Atlantic• Indian• Arctic• Southern

2VIDEO How Big is the Ocean? (5:30)

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C H E M I S T R Y

• Water is a solvent- it dissolves solutes of solids, liquids & gases

• Solute- substance that dissolves• Solution- mixture of solvent and solute

http://www.chem4kids.com/files/matter_solution.html

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C H E M I S T R Y

GASES• ATOMOSPHERE: 2 gases:

Nitrogen, Oxygen

• OCEANS: Dissolved gases: Nitrogen, Oxygen, carbon dioxide

N O CO2 2 2

ATMOSPHERE

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• Dissolved gases enter at rivers, streams, volcanic eruptions, decay, living organisms & through the water cycle

http://www.iceagenow.com/Ocean_Warming.htm6

Effects of Temperature:• Colder water dissolve gases better• Warmer water cannot hold as many gases

(remember global warming?)

http://www.middleschoolchemistry.com/multimedia/chapter5/lesson6

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• Carbon sink: ecosystem that absorbs more carbon than it lets out-

• oceans can hold carbon in the form of CO2 for thousands of years

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Ocean chemistry is currently changing at an unprecedented rate.

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SOLIDS• Sea salts: 3.5% mass of oceans• Elements-

• Chlorine (Cl)• Sodium (Na)• Potassium (K)• Calcium (Ca)• Magnesium (Mg)• Sulfur (S)

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• Salt: halite = 85% dissolved solids in ocean• Salinity: measure of the amount of dissolved

salts in a liquid

WHY IS THE OCEAN SALTY?

halite

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SALT ENTERS THE OCEAN:• Chemical weathering of minerals from land into

oceans• Volcanic eruptions• Chemical reactions between new sea floor & ocean

waterWATER IS CONSTANTLY BEING EVAPORATED, BUT SALTS REMAIN 3.6%

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C H E M I S T R Y V A R I E SLatitude & climate affect concentration of salts-

• Warm oceans evaporate more water, leaving saltier water

• Arctic areas where sea water freezes & pushes out the salt, concentrates the salt in that area

• Rainy parts of the globe receive more precipitation, diluting salt water

• Slow moving water is saltier• Areas where freshwaters empty into the ocean

are less salty (brackish)13

http://en.wikipedia.org/wiki/Salinity

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http://en.wikipedia.org/wiki/Salinity15

Density= mass divided by volume

Influencing factors:1. Salinity (more salt = more dense)2. Temperature ( cold water = more dense)

*polar regions

D E N S I T Y

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T E M P E R A T U R E• Varies with depth & location• Affected by solar energy

http://www.onr.navy.mil/focus/ocean/water/temp3.htm

DEPTH

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Can sea water freeze?• Sea water can only freeze when it

condenses such that it pushes out the salts first to make solid H O (28.4˚F)

• floating ice insulates water below it, preventing it all from freezing

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SALT

WATER

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LOCATION- Oceans are warmer near equatorial latitudes

SURFACE WATER:

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TIME OF YEAR- seasons• When the Northern Hemisphere faces away

from the sun for Winter months, those oceans are cooler

• When N. Hemisphere points towards the sun for Summer, those oceans are hotter

http://www.abc.net.au/science/articles/2011/01/20/3116529.htm

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SUMMER in N Hemisphere

WINTER in N Hemisphere

http://visibleearth.nasa.gov/view_cat.php?categoryID=1121

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DEPTH: Oceans get colder as you go deeper

1. Surface zone- top up to 300m, warmer and so less dense= difficult mixing with cooler waters below

2. Thermocline- 300-700m, temperature drops faster here with depth; colder water is more dense; holds more dissolved gases, slower currents

3. Deep zone- 700m +, cold, slowest currents

TEMPERATURE ZONES

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G L O B A L T H E R M O S T A T Oceans create climate

Ocean water and air temperature are always trying to reach equilibrium (same temp)… … But it never happens due to earth’s tilt & revolution

AIR Temp WATER

Temp

AIR CHANGES TEMPERATURE FASTER THAN WATER26

• During summer months, ocean water absorbs solar energy from the atmosphere, trying to reach equilibrium with the hot air

• Before equilibrium can be reached, seasons change- air cools for autumn

WARM WaterCOLD Water

COLD AirWARM Air

Solar Energy

SUMMER WINTER27

• When air changes to cooler, winter temperatures, oceans start to release their stored warmth to now calibrate with the cooler air temperatures: WARM OCEAN BREEZES IN THE WINTER…

• The opposite is true for Summer months:Air heats up, now oceans must absorb solar radiation to try and reach warmer equilibrium with the hot summer air: COOLER OCEAN BREEZES IN THE SUMMER…

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nice vacation spot!

nice vacation spot!

O C E A N C U R R E N T S

Current: movement of ocean water that follows a regular pattern

http://paraglidinginfo.com/2014/03/03/how-the-sun-water-and-mountains-affect-wind-patterns/

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Surface current: horizontal movements near surface, caused by wind

• Global winds• Coriolis effect: earth rotates, making water

arc instead of move in a straight line• Continental deflections: currents can’t go

through continents!

Deep currents movement of currents deep below the surface• Form where density increases

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Temperature & currents:CONVECTION- warm goes up, cold goes downThermohaline- temperature and salt affect density & controls movement

• warm currents start at equator, move toward poles• Cold currents move from poles to warm areas

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VIDEO: Making waves: the power of concentration gradients (5min)

G L O B A L C O N V E Y O R B E L T

http://www.global-greenhouse-warming.com/oceans.html

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Upwelling- movement of deep, cold, nutrient-rich water to the surface

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The Importance of Upwelling 1 min)

AN EXAMPLE:El Nino

local wind patterns (along South America) move local surface currents & so are replaced by deep cold water from below• Cold, nutrient rich water from deep ocean

rises to surface to replace warm surface water: Iron, Nitrates

• El Nino• La Nina• NOAA buoys study & predict

34VIDEO: El Nino (4:30)

• Color is determined by which light waves are reflected into our eyes

• Blue wavelengths are slow

• Composition of organic materials or pollution can give ocean different hues

C O L O R = H E A L T H

http://blogs.ei.columbia.edu/2012/05/22/the-end-of-the-line/

Turqouise = phytoplankton

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WHY IS IT IMPORTANT?• Phytoplankton: microscopic

plants that start the food chain reflect green light; water is greenish

• They need nutrients, so presence or absence of them tells the health of the ocean

“Red Tide” dinoflagellates

(Harmful Algal blooms)

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HAB

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M A P P I N G T H E F L O O R

• Sonar- sound navigation & ranging• 1970’s satellites• 1978: SeaSat network

of satellites measuring ocean direction & speed of currents

• GeoSat measures changes in ocean depth

http://science.nasa.gov/missions/seasat-1/

http://en.wikipedia.org/wiki/Geosat

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• 1977 Alvin- manned flight; discovered hydrothermal vents & ecosystem

• Deep Flight

Alvin

http://physiologizing.blogspot.com/2013/03/who-turned-up-heat.html

Deep Flight

http://seamonscience.pbworks.com/w/page/27891770/FrontPage

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Jason III & Medea 2012

http://oceanexplorer.noaa.gov/technology/subs/jason/jason.html 40

Continental shelf: gently sloping section of the continental margin between the shoreline and the slope

PICTUREContinental slope: 200m-4,000m; steeply inclined section of the continental margin between the shelf and rise

PICTUREContinental rise: base of slope; piles of sediment drop off

PICTUREAbyssal plain: 4,000m + mud & decay

PICTURE41

http://avhs2.ednet.ns.ca/staff/wile/Physiography%20of%20Continental%20Margin.html

42BACK

Mid-oceanic ridge: divergent boundaries; plates pull apart; lava bubbles up to make ridges

PICTURERift valley: flat areas in rift zones

PICTURE

Ocean trenches: cracks in ocean basin; ocean plate slides under

PICTURESea mounts: mountains under the ocean, formed on thin hot-spots in crust

PICTURE

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http://2010.polarhusky.com/logistics/oceans/geology/ 44BACK

VIDEO: The Deep Sea; Exploring the Zones (6min)

L I F E

1. plankton float near the surface, microscopic food for organisms

1. Phytoplankton: autotrophs2. Zooplankton: heterotrophs

2. nekton: swim freely (fish, mammals, etc)

3. benthos: live on or near ocean floor (crabs, sponges, starfish, worms, seaweed, clams)

45VIDEO: The secret life of plankton (6 min)

Food Chain: shows how Energy flows from one organism to another

Food Web: shows feeding relationships1. aquatic2. terrestrial

• Interconnected: carbon from trees & debris support aquatic life

• amphibians live in both

• food for land animals

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VIDEO: A guide to the energy of the Earth (4:40)

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M A R I N E Z O N E S

Water depthAmount of sunlight

1. Intertidal zone: ocean meets land• exposed to air part of the day• waves, beaches

2. Neritic zone: deeper; floor slopes• warm water, sunlight• (corals, sea turtles, fish, dolphins, plankton,

seaweed)48

3. Oceanic zone: sea floor drops sharply• Deep water of open ocean• Plankton on surface, fish, whales, shark

4. Benthic zone: ocean floor• No sunlight at deepest parts; cold• Adaptations for low temp & no light-• chemosynthesis begins food chain• Bacteria, worms, sea urchins

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http://www.bio.utexas.edu/faculty/sjasper/Bio213/aquahab.html50

M A R I N E E C O S Y S T E M S

1. Intertidal areas: near shore• Mudflats- worms, crabs, shorebirds• Sandy beaches- worms, crabs, clams, plankton• Rocky shores- live underwater & exposed to air

http://commons.wikimedia.org/wiki/File:A_shot_of_a_mud_flat_in_an_unconsolidated_shore_in_Alaska.jpg

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MUDFLATS

http://mmm-yoso.typepad.com/mmmyoso/lanai/ 52

SANDY BEACH

ROCKY SHORE

VIDEO: Intertidal Biome (7 min)

2. Coral reefs: warm, shallow neritic zone• Corals- living polyps form colonies over calcium

remains of ancestors• Second most diverse habitat (2nd to RF)• (algae, brightly colored fish, sponges, sea stars,

sea urchins)

http://www.theguardian.com/environment/2011/feb/23/coral-reef-report-dying-danger 53

http://darwinsreef.pbworks.com/w/page/66265215/Cor

al%20Polyp

VIDEO: What are Coral Reefs and what’s their purpose? (5min)

3. Estuaries: where freshwater from river meets ocean water• Rich in minerals • Productive ecosystems• Prone to pollution & runoff• (Plankton, dolphin, manatee, seal, fish, plants,

migratory birds, invertebrates)

http://thetechjournal.com/science/vast-freshwater-reserves-discovered.xhtml

http://oceanservice.noaa.gov/facts/estuary.html

54VIDEO: Estuarine Ecology (4:30)

4. Mangrove swamps: swamps along the coast of tropical areas• Protect coastlines from erosion & damage from

storms• Breeding & feeding grounds for birds & other

animals

http://en.wikipedia.org/wiki/Mangrove 55

VIDEO: Into the mangrove Forest (6min)

5. Sargasso Sea- mid Atlantic • Floating rafts of algae sargassum

http://waittfoundation.org/sargasso-sea-protection/

http://blog.mailasail.com/eddienic/40 56

VIDEO: Big Changes in the Sargasso Sea (3min)

6. Polar ice: Arctic and Southern Oceans• Rich in nutrients; plankton• (Fish, birds, Beluga whales, penguins)

http://vishnu.whoi.edu/services/communications/oceanusmag.050826/v43n2/wiebe.html

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7. Pacific Garbage Patch

http://sites.psu.edu/civicissuesalaina/2013/02/26/ocean-roomba-and-an-unexpected-pollutant/

http://pixgood.com/pacific-garbage-patch-aerial-view.html

58VIDEO: The nurdles quest for

ocean domination 5 min

FOOD• Multi-billion dollar industry• Fish, shrimp, oysters, crabs, mussels• 75 million tons of fish/yr• Overfishing• Nets & trawlers damage wildlife (bycatch)• Fish farms

O C E A N R E S O U R C E S

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VIDEO: Overfishing (2:30)

Seaweed:• kelp thickener for ice cream, Jell-O;• Protein- Asian staple

http://www.theguardian.com/global-development/2012/jan/22/future-of-food-john-vidal 60

NONLIVING RESOURCES1. Oil & natural gas – under layers of

impermeable rock DRILLNONRENEWABLE• Used up faster than can be replaced naturally

http://eatsleepplaybeaufort.com/city-of-beaufort-passes-resolution-opposing-offshore-drilling/61

2. Freshwater Desalination – removing salt water from water; expensive; Saudi Arabia

• Evaporation –Heat Method: Burn/heat fossil fuels to evaporate & collect water vapor

http://www.ecomena.org/tag/water/

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Ocean Water Battery!

http://www.wired.com/2011/04/battery-ocean-saltwater/

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http://www.survivalreadyblog.com/survival-skills/category/wilderness-survival 64

Desalination tent survival gear

• Freeze method-freeze ocean water to remove salt

http://www.desalination.com/wdr/49/27/freeze-desalination-look-ahead 65

Oil barrier

Ice

Salt water

• Reverse osmosis filtration pressure causes water to go through semi-permeable membrane: water can go through but salt & impurities cannot

http://sdhydroponics.com/resources/articles/gardening/how-to-install-a-reverse-osmosis-system

http://tacticalintelligence.net/blog/lifestraw-personal-water-filter-review.htm

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3. Sea floor minerals: mineral nodules- ocean floor• Manganese (to make steel)• Iron, copper, nickel, Phosphates• Nodules form from dissolved substances in sea

water that stick to solid objects (rocks)• 15% ocean floor covered in nodules• Deep; difficult & costly mining

http://www.21stcentech.com/headlines-21st-century-tech-march-22-2013/

http://eatingjellyfish.com/?tag=manganese-nodules

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4. Tidal or Wave Energy: Energy from movement• Water during high tide rushes through narrow

coastal passageway• Water’s force can turn turbines to generate E

*RENEWABLE clean, inexpensive

http://science.howstuffworks.com/environmental/earth/oceanography/wave-energy2.htm 68

P O L L U T I O N

Non-point pollution pollution from many sources• Oil/gas leaked from cars• Personal water craft leak• Pesticides, herbicides from golf courses,

farmland, home lawns

http://oceanservice.noaa.gov/education/kits/pollution/04nonpointsource.html69

Point-source pollution pollution comes from a specific site (Leaking oil tanker, Factory, Wastewater treatment plan)

VIDEO: Ganges River pollution

http://web.mit.edu/12.000/www/m2011/finalwebsite/solutions/environment/pollution_nonpoint.shtml

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1. Trash dumping-• 1980’s scientists alarmed at type of trash

washing on beachs; bandages, vials of HIV blood, syringes

• EPA investigated: 3 million tons of medical waste/yr has to now go into landfills

• Dumping in deeper ocean still commonhttp://asklizweston.com/are-you-ready-for-a-zero-waste-lifestyle/

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2. Plastic-• Plastic never decomposes• Pacific garbage pack- kills wildlife

http://www.energydigital.com/greentech/1982/Plastic-in-the-Ocean:-What039s-the-Solution

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3. Sludge dumping- part of treated raw sewage• By 1990 US had discharged 38 trillion liters of

treated sludge into coastal waters• Pollutes beaches; kills marine life• Banned, but still practiced

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4. Oil spills- tankers transport oil can spill

http://response.restoration.noaa.gov/oil-and-chemical-spills/significant-incidents/exxon-valdez-

oil-spill/how-toxic-oil.html

http://www.adn.com/slideshow/photos-exxon-valdez-oil-spill-archive

• 1990 double hulled tankers required by the Oil pollution Act (response to March 1989 Exxon Valdez spill in Alaska)

• Compliance has been slow

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• Gulf Coast spill April 2010 (3.2 million barrels of oil into the Gulf) BP Oil

http://knowledge.allianz.com/environment/pollution/?751/gulf-of-mexico-oil-spill-causes-and-effects-gallery

http://topics.nytimes.com/top/reference/timestopics/subjects/o/oil_spills/gulf_of_mexico_2010/index.html

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VIDEO: Timeline of Gulf Oil Disaster (4min)

CITIZEN POWER• 1980’s citizens organized beach cleanups• Semi-annual Adopt-a-Beach program

http://greatlakes.org/SAAB

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1972 Clean Water Act put EPA in charge of issuing of permits for trash dumping into oceans

1972 US Marine Protection Research & Sanctuaries Act prohibits dumping any harmful material into marine environments

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RESOURCES

• NC 8th grade Holt Science & Technology: Holt, Rinehart & Winston, 2005.

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