Do Now

Do Now• Sit SILENTLY and answer the following in your notes.

You do not have to copy the questions, though I am confident some of you will still ask…le sigh

• What are the 2 atoms that make up a water molecule?• Balance the following…

– ___H2 + ____O2 ____H2O

• If water changes from a solid to a liquid to a gas then it is undergoing what kind of change? How do you know?

• What are some ways that we as humans pollute water systems?

What makes water so What makes water so special?special?

WaterWater

•A water molecule (H2O), is made up of threethree atoms --- one oxygen and two hydrogen.

H

HO

Special Properties

• Water is the only substance on Earth that occurs naturally as a solid, a liquid, and a gas.

• It is often referred to as ‘the universal solvent’ because so many other substances dissolve in it.

• This characteristic is one reason that the water encountered on Earth is rarely pure.

So…what makes water so So…what makes water so special?special?

Water is Polar!!!!Water is Polar!!!!

• The oxygenoxygen end “acts” negativenegative• The hydrogenhydrogen end “acts” positivepositive• Causes the water to be POLAR, POLAR,

like a magnet.like a magnet.

Hydrogen Bonds Exist Hydrogen Bonds Exist Between Water MoleculesBetween Water Molecules• Formed between a Formed between a

highly highly Electronegative atom Electronegative atom (like oxygen in (like oxygen in another water) of a another water) of a polar molecule and a polar molecule and a hydrogenhydrogen

• Weak bond, but Weak bond, but strong in great strong in great numbersnumbers

Interaction Between Interaction Between Water MoleculesWater Molecules

Negative Oxygen Negative Oxygen end of one water molecule is end of one water molecule is attracted to the attracted to the Positive Hydrogen Positive Hydrogen end of end of

another water molecule to form a another water molecule to form a HYDROGEN HYDROGEN BONDBOND

What are What are the the

PropertieProperties of s of

Water?Water?

Properties of WaterProperties of Water

•CohesionCohesion

Properties of WaterProperties of Water

•CohesionCohesion•AdhesionAdhesion

Properties of WaterProperties of Water

•CohesionCohesion•AdhesionAdhesion•High Specific HeatHigh Specific Heat

Properties of WaterProperties of Water

•CohesionCohesion•AdhesionAdhesion•High Specific HeatHigh Specific Heat•High Heat of High Heat of VaporizationVaporization

Properties of WaterProperties of Water

•CohesionCohesion•AdhesionAdhesion•High Specific HeatHigh Specific Heat•High Heat of High Heat of VaporizationVaporization

•Less Dense as a SolidLess Dense as a Solid

CohesionCohesion• Attraction between particles of Attraction between particles of

the same substance the same substance (( why water why water is attracted to itself)is attracted to itself)

• Results in Results in surface tensionsurface tension (a (a measure of the strength of watermeasure of the strength of water’’s surface)s surface)

Cohesion …Cohesion …

Helps insects walk across water, but how is it helpful to people?

AdhesionAdhesion• Attraction between two different Attraction between two different

substancessubstances..• Water will make Water will make hydrogen bonds with hydrogen bonds with

other surfacesother surfaces such as glass, soil, such as glass, soil, plant tissues, and cotton. plant tissues, and cotton.

• CapillaryCapillary actionaction-water molecules will -water molecules will ““towtow”” each other along when in a thin each other along when in a thin glass tube.glass tube.

Adhesion Causes Adhesion Causes Capillary ActionCapillary Action

Which gives water the ability to “climb”

structures

High Specific HeatHigh Specific Heat• Amount of heatAmount of heat needed to raise or needed to raise or

lower lower 1g1g of a substance of a substance 1° C1° C..

• Water Water resistsresists temperature changetemperature change, , both for heating and cooling.both for heating and cooling.

– Would you rather walk on sand or in Would you rather walk on sand or in water on a beach on a hot summer day?water on a beach on a hot summer day?

– Which would be warmer that night? Which would be warmer that night? Why?Why?

High Heat of High Heat of VaporizationVaporization

• Water vapor Water vapor forms a kind of global ‘‘blanket” which helps to keep the Earth warm.

• Heat radiated from the sun Heat radiated from the sun warmed surface of the earth is

absorbed and held absorbed and held

by the vaporby the vapor.

Water is Less Dense as Water is Less Dense as a Solida Solid

•Which is ice and which is Which is ice and which is

water?water?

Exit Ticket1.Draw a water molecule with labeled atoms and charges.

2.What is the property called that describes water sticking to itself?

3.Is ice les dense or more dense than liquid water? How do you know?

Do Now

• Why is water’s property of high heat of vaporization important to the earth and more specifically to us?

• What 2 properties of water are important for plants specifically and why?

• Explain why solid water (ice) is able to float on liquid water.

Water Distribution

• Water covers approximately 71% of the Earth’s surface (USGS). Most of this water (97%) is not drinkable because it is saltwater.

Water Distribution

• The majority of freshwater (3%) exists in ice caps, glaciers, and oceans.

• 77% of the freshwater is frozen. Of the 23% that is not frozen, approximately a half of a percent is available to supply living organisms with what they need to survive.

• The availability of water varies with local geography and allows humans to utilize water as a resource.

Salinity

• Salinity = total amount of solid material dissolved in water

• Can be determined by measuring water conductivity

• Typically expressed in parts per thousand (‰)

Figure 5-15

So why is the Ocean so Salty?!

• Dissolved chemicals eroded from the Earth's crust and washed into the sea.

• Solid and gaseous ejections from volcanoes, suspended particles swept to the ocean from the land by onshore winds, and materials dissolved from sediments deposited on the ocean floor have also contributed.

Salinity Cont.• Salinity in ocean waters is increased by

evaporation or by freezing of sea ice and it is decreased as a result of rainfall, runoff, or the melting of ice. The average salinity of seawater is 35 parts per thousand(3.5%). Salinities are much less than average in coastal waters, in the polar seas, and near the mouths of large rivers.

• In recent years, salinity has been changing across the world’s oceans. Why do you think that is?

Processes affecting seawater salinity

• Processes that decrease seawater salinity:– Precipitation– Runoff– Icebergs melting– Sea ice melting

• Processes that increase seawater salinity:– Sea ice forming– Evaporation– Hydrothermal vents

What are Hydrothermal Vents?

Hydrothermal Vent• Hydrothermal vent- a deep-sea hot spring

where heated seawater forces its way up through the crust.

• Discovered rich communities in 1977.• Temperatures range from 10-20⁰C (50-68⁰F)

to 350⁰C (660⁰F).• Mineral particles such as sulfides and

carbonates precipitate to form chimneys.

Mid-Ocean Ridge

Hydrothermal Vents

Where are vents located?

Where magma is close to the surface – Mid Ocean Ridges.

Mid-Ocean Ridges

http://www.divediscover.whoi.edu/ridge/axial.html

19771st vent found by Alvin

Alvin?

Alvinhttp://www.youtube.com/watch?v=XotF9fzo4Vo

Submersibles, ROVs, & AUVs

http://www.divediscover.whoi.edu/vents/vent-infomod.html

STEP 1

•Cold water (2oC) seeps through cracks and is heated up (up to 400oC)

How are vents created?

STEP 2

•Water heated to 350-400oC – high temps. facilitate leaching of minerals from rock.

•Oxygen is removed chemically

•Picks up dissolved metals (Fe, Cu, Zn).

•H20 picks up Hydrogen sulfide.

STEP 3

•Hot liquid under pressure finds an exit.

•Dissolved metals and H2S are carried up and out.

•Effluent is acidic and toxic to most animals.

White and Black Smokers

Black SmokerHottest of all vents

monosulfide. This compound gives the smoker its black color.They spew mostly iron and sulfide, which combine to form iron monosulfide. This compound gives the smoker its black color.

WHITE SMOKERS

•White smoke contains silica

•Anhydrite is created (white mineral)

•Contains compounds of barium, calcium, and silicon

Still hot enough to cook pasta – but not as hot as black smokers

Vent crabs

Zooarcid Fish (Eelpout)

Giant Vent Mussel

Lepetodrilus- limpets

Pompeii Worm

Giant Hydrothermal Vent Clam

Anemones

Constituents of ocean salinity

• Average seawater salinity = 35‰ (3.5%)

• Main constituents of ocean salinity:– Chloride (Cl–)– Sodium (Na+)– Sulfate (SO4

2–)– Magnesium (Mg2+)

Figure 5-13

Salinity variations

Location/type Salinity

Normal open ocean 33-38‰

Baltic Sea 10‰ (brackish)

Red Sea 42‰ (hypersaline)

Great Salt Lake 280‰

Dead Sea 330‰

Tap water 0.8‰ or less

Premium bottled water 0.3‰

Seawater desalination

• Desalination methods:– Distillation

• Solar

• Heat

– Electrolysis– Reverse osmosis– Freeze separation

Figure 5-25

Distillation

Reverse Osmosis

Figure 5-26

But why do we really care about salinity anyway?

• The ocean currents are affected by salinity and ocean currents regulate climate around the world.

• The earths oceans and seas are also the biggest recyclers of gasses in the atmosphere.

• Finally the oceans store heat that allows us to have the seasons.

What are Currents?

• Currents are the slow movement of sea water by different factors– Surface currents are caused by wind and

temperature variations – Deeper currents are caused by changes in

density (salinity) and temperature– http://www.youtube.com/watch?

v=qeZgJzt3m04

Heat Transport by Currents

• Surface currents play significant roles in transport heat energy from equatorial waters towards the poles

• May serve as “heat sources” to cooler overlying air, “heat sinks” from warmer

• Evaporation and condensation participate in latent heat exchanges

Matter Transport and Surface Currents

• Currents also involved with gas exchanges, especially O2 and CO2

• Nutrient exchanges important within surface waters (including outflow from continents) and deeper waters (upwelling and downwelling)

• Pollution dispersal• Impact on fisheries and other resources

The currents move in a circular motion

Deep current and Surface current interaction

What happens to the regular cycle when salinity is disrupted?

• The normal circular motion gets bent and skewed a bit.

Gyres are large circular-moving loops of waterFive main gyres (one in each ocean

basin):• North Pacific• South Pacific• North Atlantic• South Atlantic• Indian

• Generally 4 currents in each gyre• Centered about 30o north or south

latitude

Current GyresCurrent Gyres

• “Great Pacific Garbage Patch”

• Estimate: 46,000 pieces of floating garbage/mi2.

North Pacific Subtropical Gyre

North Pacific Subtropical Gyre

135° to 155°W and 35° to 42°N

North Pacific Subtropical Gyre

http://marinedebris.noaa.gov/info/patch.html#6

Great Pacific Garbage Patch- Good Morning America 2010http://www.youtube.com/watch?v=Co43TXJXryI

What do Nike shoes, What do Nike shoes, rubber ducks, and hockey rubber ducks, and hockey gloves have to do with gloves have to do with currents?currents?

Lost at Sea

•January 1992 - shipwrecked in the Pacific Ocean, off the coast of China

•November 1992 - half had drifted north to the Bering Sea and Alaska; the other half went south to Indonesia and Australia

•1995 to 2000 - spent five years in the Arctic ice floes, slowly working their way through the glaciers2001 - the duckies bobbed over the place where the Titanic had sunk

•2003 - they were predicted to begin washing up onshore in New England, but only one was spotted in Maine

•2007 - a couple duckies and frogs were found on the beaches of Scotland and southwest England.

Duckie Progress

The Water Cycle

By Mr. Miller

Water never leaves the Earth. It is constantly being cycled through the atmosphere, ocean, and land. This process, known as the water cycle, is driven by energy from the sun. The water cycle is crucial to the existence of life on our planet.

The Water Cycle

During part of the water cycle, the sun heats up liquid water and changes it to a gas by the process

of evaporation. Water that evaporates from Earth’s oceans, lakes, rivers, and moist soil rises

up into the atmosphere.

The process of evaporation from plants is called The process of evaporation from plants is called transpirationtranspiration. (In other words, it. (In other words, it’’s like plants s like plants sweating.)sweating.)

As water (in the form of gas) rises higher in the atmosphere, it starts to cool and become a liquid again.

This process is called condensation. When a large amount of water vapor condenses, it results in the

formation of clouds.

When the water in the clouds gets too heavy, the water falls back to the earth. This is called

precipitation.

When rain falls on the land, some of the water is absorbed into the ground forming pockets of water called groundwater. Most groundwater eventually

returns to the ocean. Other precipitation runs directly into streams or rivers. Water that collects in rivers,

streams, and oceans is called runoff.

Stormwater Runoff and Water Quality

Stormwater Runoff

Definition:

Rainfall that, instead of soaking into the ground, flows into water bodies picking up pollutants along the way

http://www.kytc.state.ky.us/EnvAnalysis/Stormwaterquality/Gen_info_edu.htm

River Basin

Definition: defined area where all water within the area flows into a common water body

There are 17 different river basins in NCYou live in the Catawba River Basin, which

has the largest number of people so what implications do you think there are for the environment here?

NC River Basins

http://www.cgia.state.nc.us/Portals/0/images/examples/nc_rivbasins.jpg

Pollution

As stormwater flows across streets and lawns, it picks up chemical pollutants

All pollution in a river basin accumulates in the common water body

Types of Pollution

Point Source Pollution

Definition-localized source of pollution, usually industrial and coming from a pipe Examples

Industry

Nonpoint Source Pollution

Definition- general and indirect water pollution from many diffuse sources

Examples Agricultural Runoff Animal Waste Residential Property Runoff Parking Lot and Road

Runoff

http://www.liverpool.nsw.gov.au/LCC/INTERNET/me.get?site.sectionshow&PAGE1230&BODY

What’s wrong with this picture?

http://www.ncstormwater.org/pages/workbook_pollution_solutions.html

Visual Indicators of Water Quality

Diverse OrganismsBugs as Indicators of Water Quality

Mayflies and Caddisflies cannot tolerate water pollution, therefore their presence in a water body indicates good water quality.

Mayfly larvaehttp://swittersb.files.wordpress.com/2008/08/mayfly20nymph.jpg

Caddisfly larvaehttp://www-staff.lboro.ac.uk/~gymfj2/Caddisfly.htm

Measuring Water Quality

Dissolved OxygenWater TemperaturepHExtremely high or low

levels of any of these indicate poor water quality

A YSI Meter is used to measure these quantities.

How do we cleanse our waters?!

Riparian buffersWetlandsStormwater Best Management Practices

Raingardens, Cisterns, Rain Barrels, Permeable Pavement