Oceanography Chapter 6

Front 1

How does water influence global temperatures?

Back 1

it prevents swings of temperature by holding heat during the day and releasing it at night.

Front 2

hydrolic cycle

Back 2

powered by solar radiation, water vapor rises from the sea, condenses into clouds and forms rain and snow, falls on the land and is eventually deposited back into the ocean.

Front 3

where does most of the precipitated water fall?

Back 3

back into the ocean

Front 4

what is the average time water stays in the ocean before being evaporated?

Back 4

4,100 years

Front 5

what is the residence time of water in the air?

Back 5

9 days about.

Front 6

Empedocles

Back 6

5th century, suggested that all matter is composed of earth, air, fire and water.

Front 7

Lavoisier

Back 7

discovered water could be subdivided into two gases

Front 8

molecule

Back 8

a group of atoms held together by chemical bonds

Front 9

chemical bonds

Back 9

the energy relationships between atoms that hold them together; formed when electrons are shared between atoms or are moved from on atom to another.

Front 10

electron

Back 10

tiny negatively charged particles found towards the outside of an atom

Front 11

covalent bond

Back 11

the bonds formed by shared pairs of electrons

Front 12

What is water's shape?

Back 12

bent or angular

Front 13

Why is water bent?

Back 13

the electron distribution has 2 pairs of electrons and 2 unpaired for the oxygen molecule so the paired electrons push the Hydrogen molecules away.

Front 14

What is the angle between the hydrogen molecules in water?

Back 14

105 degrees

Front 15

polar

Back 15

electrically asymmetrical due to shape

Front 16

protons

Back 16

positively charged particles at the center of atoms

Front 17

What happens when water comes into contact with another polar molecule (not water)?

Back 17

the water separates the compounds elements from each other

Front 18

Why is water attracted to itself?

Back 18

polarity

Front 19

hydrogen bond

Back 19

when a hydrogen atom is attracted to a negative molecule

Front 20

what holds water molecules together?

Back 20

hydrogen bonds (electrostatic forces)

Front 21

cohesion

Back 21

property of molecules to stick together

Front 22

what does cohesion allow?

Back 22

it allows a high surface tension because of hydrogen molecules.

Front 23

adhesion

Back 23

tendency of water to stick to solids

Front 24

Why is water a pale blue (molecular reasoning)?

Back 24

the hydrogen bonds

Front 25

give an example of water in a very long part of the hydraulic cycle.

Back 25

a water molecule in the ocean is going to take about 4,100 years to get into the atmosphere.

Front 26

give an example of water in a very short, rapid part of the hydrologic cycle.

Back 26

a water molecule in the atmosphere will be there for only 9 days

Front 27

how are atoms different from molecules?

Back 27

two or more atoms that are held together by a bond form a molecule.

Front 28

what holds molecules together?

Back 28

molecules are held together by bonds such as a hydrogen or covalent bonds.

Front 29

why is water a polar molecule?

Back 29

water is a polar molecule due to the shape of being bent. This bent shape means that there are two electron pairs not sharing a covalent bond and are therefore creating a negative side of the molecule.

Front 30

What properties of water derive from its polar nature?

Back 30

Water is cohesive (high surface tension) and adhesive (tendency to stick to other materials).

Front 31

Why does a mass of water look blue?

Back 31

the hydrogen bonds are stretched and compressed creating a vibrating that absorbs a small amount of red light that allows blue light to reach our eyes.

Front 32

heat

Back 32

energy produced by the random vibration of atoms or molecules

Front 33

what is heat a measure of?

Back 33

how many molecules are vibrating and how rapidly they are vibrating

Front 34

what does temperature record?

Back 34

how rapidly the molecules are vibrating

Front 35

temperature

Back 35

an objects response to an input (or removal) of heat

Front 36

degree

Back 36

how temperature is measured; 1 C = 1.8F

Front 37

why is celsius more useful?

Back 37

because freezing is 0 and boiling is 100

Front 38

heat capacity

Back 38

a measure of the heat required to raise the temperature of 1 gram of substance by 1 C

Front 39

How is heat capacity measured? (units)

Back 39

measured in calories per gram

Front 40

calorie

Back 40

the amount of heat required to raise the temperature of 1 gram of pure water by 1 C

Front 41

What is the heat capacity of water so high?

Back 41

hydrogen bonds; water can absorb (or release) large amounts of heat while changing relatively little in temperature.

Front 42

density

Back 42

mass per unit volume

Front 43

what is the density of water?

Back 43

1 gram per centimeter cubed

Front 44

What happens when water gets colder?

Back 44

it gets denser but as it approaches the freezing point it gets less dense.

Front 45

density curve

Back 45

shows the relationship between the temperature (or salinity) of a substance and its density

Front 46

at what temperature is water densest?

Back 46

3.98 C

Front 47

state

Back 47

an expression of the internal form of a substance

Front 48

Why does water loose density when if freezes?

Back 48

the hydrogen bonds become more rigid and spread out.

Front 49

freezing point

Back 49

transition from liquid to solid when the bond angle widens to create a lattice

Front 50

What happens when water freezes (energy)

Back 50

heat is continually removed by temperature doesn't change until all the water is frozen since heat is released as hydrogen bonds form into a lattice.

Front 51

sensible heat

Back 51

a detectable decrease in heat

Front 52

latent heat of fusion

Back 52

the measure of heat that must be removed for a state change that is undetectable to a thermometer.

Front 53

what does a straight line represent on a graph (temperature vs time)

Back 53

latent heat/state change

Front 54

What happens when water changes states from water to vapor?

Back 54

heat is needed to break the hydrogen bonds so it cools the surface

Front 55

latent heat of vaporization

Back 55

the amount of energy required to break hydrogen bonds

Front 56

how is heat different form temperature?

Back 56

heat measures how many molecules are vibrating and how rapidly they are vibrating whereas temperature records how rapidly the molecules are vibrating

Front 57

what is meant by heat capacity? Why is the heat capacity of water so unique?

Back 57

heat capacity is the measure of heat required to raise the temperature of 1 gram by 1 C. Water is unique in this trait because it has large amounts of hydrogen bonds that require more heat to move the molecules.

Front 58

what factors affect the density of water?

Back 58

The density of water is affected by temperature and salinity.

Front 59

Why does cold air or water tend to sink? what role does salinity play?

Back 59

cold water or air tends to sink because, generally, the colder the substance the denser it gets. Salinity has a direct relationship with density, the higher the salinity the higher the density.

Front 60

how is water's density affected by freezing? why does ice float?

Back 60

when water freezes the hydrogen bonds stiffen creating a lattice and spreading the water molecules apart making ice less dense than liquid water so it floats.

Front 61

what is the difference between sensible and nonsensical heat?

Back 61

sensible heat is a detectable decrease in heat by a thermometer, yet nonsensical heat is not sensible by a thermometer. Nonsensical heat is when freezing or vaporization occurs and heat is used or given off that must be regenerated to continue the process (no change in temperature)

Front 62

what is the latent heat of fusion of water?

Back 62

80 cal/g

Front 63

what is the latent heat of vaporization?

Back 63

540 cal/g

Front 64

Why do we use the term 'latent' ("hidden")?

Back 64

There is no discernible temperature change but heat is still needed to cause the change in state.

Front 65

thermostatic properties

Back 65

properties that act to moderate changes in temperature

Front 66

thermal inertia

Back 66

tendency of a substance to resist change in temperature with the gain or loss of heat energy

Front 67

thermal equillibrium

Back 67

the total incoming heat, plus that of earthly sources, equals the total outgoing heat into space.

Front 68

how much of poleward transfer of heat is air responsible for?

Back 68

2/3

Front 69

What is thermal inertia?

Back 69

thermal inertia is the tendency of a substance to resist change in temperature with the gain or loss of heat energy.

Front 70

Why is the fact that ice floats important to Earth's generally moderate climate?

Back 70

because ice floats, it soaks up the suns energy, melts, then refreezes at night giving back the stored energy to the atmosphere.

Front 71

how is heat transported from tropical regions to polar regions?

Back 71

heat is mostly transported by the water vapor (since it holds more heat) and the rest is transported by heated water that flows south or north from the equator.

Front 72

ion

Back 72

an atom (or small group of atoms) that becomes electrically charged by gaining or losing one or more electrons

Front 73

what kind of molecule (polar vs non polar) does a polar molecule effect?

Back 73

polar.

Front 74

salinity

Back 74

the total concentration of dissolved inorganic solids in water

Front 75

what causes salinity to vary?

Back 75

evaporation, precipitation, and runoff from continents

Front 76

what is the average salinity

Back 76

3.5%

Front 77

what are the most abundant ions in seawater?

Back 77

chloride and sodium ions

Front 78

trace element

Back 78

present in the seawater in amounts less than 0.001% (one part per million (ppm))

Front 79

excess volitiles

Back 79

the components of ocean water whose proportions are not accounted for by the weathering of surface rocks

Front 80

what does ocean spreading centers do to the seawater?

Back 80

they filter magnesium and sulfate ions out of the water and replace them with calcium and potassium

Front 81

how often do spreading centers filter ocean water?

Back 81

every 1 to 10 million years

Front 82

Georg Forchhammer

Back 82

although the total amount of dissolved solids might vary among the samples, the ratio of major salts was constant.

Front 83

principle of constant proportions

Back 83

the proportions of major conservative elements in seawater remain nearly constant, though total salinity may change with location; also called Forchhammers principle

Front 84

why can't you measure salinity by weight?

Back 84

some of the molecules retain water and when you heat those up to evaporate the water other molecules break apart or dissolve into gas.

Front 85

practical salinity scale

Back 85

a ratio of the conductivity of a seawater sample to a standard solution of potassium chloride.

Front 86

salinometer

Back 86

measures the ration of conductivity

Front 87

chemical equillibrium

Back 87

the proportions and amounts of dissolved salts per unit volume of ocean are nearly constant

Front 88

residence time

Back 88

the average length of time an element spends in the ocean

Front 89

what is the residence time in the ocean and in the air?

Back 89

4,100 years in the ocean, and 9 days in the air

Front 90

mixing time

Back 90

1,600 years due to vigorous currents

Front 91

how is seawater's salinity expressed?

Back 91

ppm or parts per million

Front 92

other than hydrogen and oxygen, what are the most abundant ions in seawater?

Back 92

sodium and chloride

Front 93

what are the sources of the ocean's dissolved solids?

Back 93

the sources of the ocean's dissolved solids are from the continents, separated salts, dissolved substances, and the mantle

Front 94

what is the principle of constant proportions?

Back 94

the constant ratio of major salts through all of the water samples and oceans

Front 95

how is salinity determined?

Back 95

salinity is determined by the practical salinity scale which is a ratio of the conductivity of a seawater sample to a standard solution of potassium chloride.

Front 96

what is meant by "residence time"? Does seawater itself have a residence time?

Back 96

the residence time is the average length of time an element spends in the ocean. Water has a residence time of 4,100 years and an atmosphere residence time of 9 days.

Front 97

What are the major gases found in the seawater?

Back 97

Nitrogen, oxygen, and carbon dioxide

Front 98

do gases dissolve more readily in hot or cold water?

Back 98

cold

Front 99

What is nitrogen used for in organisms?

Back 99

to build proteins and other important biological chemicals

Front 100

what does CO2 do upon combining with water?

Back 100

it forms a weak acid

Front 101

Does more CO2 flow from the atmosphere to the ocean or the ocean to the atmosphere?

Back 101

atmosphere to the ocean

Front 102

describe the oxygen gradient as you increase in depth.

Back 102

the oxygen concentrations decrease through mid-depths then rise again towards the bottom.

Front 103

which dissolves more gas per unit volume: cold seawater or warm seawater?

Back 103

cold seawater dissolves more gas

Front 104

what happens when carbon dioxide dissolves in seawater?

Back 104

the carbon dioxide is used in photosynthesis, creates a weak acid or is locked as carbon ions for sedimentation.

Front 105

how do concentrations of oxygen and carbon dioxide vary with ocean depth?

Back 105

carbon dioxide increases with depth whereas oxygen decreases at mid-depth then increases again at depth.

Front 106

acid

Back 106

a substance that releases a hydrogen ion in solution; pH of 0<x<7

Front 107

base

Back 107

a substance that combines with a hydrogen ion in solution; pH of 7<x<14

Front 108

alkaline

Back 108

a basic solution or ion

Front 109

pH scale

Back 109

measures the concentration of hydrogen ions in a solution; logarithmic

Front 110

how much does one pH unit represent?

Back 110

a 10 fold concentration change

Front 111

what is neutral pH

Back 111

7, pure water

Front 112

what is seawater's pH?

Back 112

slightly alkaline 7<x

Front 113

What does CO2 break down intwine dissolved?

Back 113

hydrogen ions, bicarbonate ions, and carbonate ion

Front 114

buffer

Back 114

prevents broad swings of pH when acids or bases are added

Front 115

what creates more basic water?

Back 115

more plant growth and warm temperatures

Front 116

does water become more acidic or less acidic with depth?

Back 116

more acidic

Front 117

how is pH expressed? What's neutral?

Back 117

pH is a logarithmic value that is measured by the concentration of H+ ions in a solution. Neutral, which is 7 pH has equal H+ ions and OH- ions.

Front 118

what is a buffer? how might seawater's ability to act as a buffer be important?

Back 118

a buffer prevents swings in pH balance when acids (co2) and bases are added to solution (ocean). This allows the ocean to have a steady pH (relatively) while gases defuse into and out of it.

Front 119

what is the density of water a function of?

Back 119

temperature and salinity

Front 120

when does density increase?

Back 120

increase in salinity, pressure and decreasing temperature

Front 121

What zones is the ocean divided into?

Back 121

surface zone, pycnocline, and deep zone

Front 122

surface zone

Back 122

upper layer of the ocean; temperature and salinity are relatively constant; water is in contact with the atmosphere and is exposed to sunlight; 150 meters deep but may be deeper or absent.

Front 123

mixed layer

Back 123

another name for the surface zone

Front 124

pycnocline

Back 124

a zone in which density increases with increasing depth; this zone isolates the surface water from the deep zone.

Front 125

deep zone

Back 125

zone beneath the pycnocline at depths below 1000 meters; little change in density as depth increases; 80% of all ocean water

Front 126

thermocline

Back 126

the middle layer in which the temperature drops rapidly with depth

Front 127

Are polar waters stratified by temperature

Back 127

no

Front 128

halocline

Back 128

a zone of rapid salinity increase with depth

Front 129

water mass

Back 129

a body of water with characteristic temperature and salinity and therefore density

Front 130

where do all layers originate (of the ocean)?

Back 130

at the surface

Front 131

why do deep water masses retain their identity a long time?

Back 131

little energy is available for mixing in the quiet depths.

Front 132

how is the ocean stratified by density? What names are give to the ocean's density zones?

Back 132

the ocean has three density zones, the surface zone, the pycnocline, and the deep zone. Each of these has a different density. The colder water with a high salinity is on the bottom and the warmer, non saline water is on the top.

Front 133

what, generally, are the water characteristics of the surface zone? Do these conditions differ significantly between the polar regions and the tropics?

Back 133

the temperature and density are relatively constant, the surface zone in the tropics can extend 1000 meters or be absent in polar regions.

Front 134

what, generally, are the water characteristics of the deep zone? Do these conditions differ significantly between the polar regions and the tropics?

Back 134

the deep zone gets denser with depth, colder with depth, and is very shallowly located at polar regions and deeper at tropical regions.

Front 135

how is the pycnocline related to the thermocline and the halocline?

Back 135

the pycnocline increases with depth because the thermocline decreases and the halo cline increases (generally).

Front 136

how is water mass defined?

Back 136

water mass is a body of water with characteristic temperature and salinity, and therefore density

Front 137

how does the ocean's density stratification limit the vertical movement of seawater?

Back 137

density stratification keeps cold water down and warm water up so they don't connect. There is also very little energy at depths that is available for vertical mixing.

Front 138

light

Back 138

a form of electromagnetic radiation, or radiant energy, that travels as waves through space, air, and water.

Front 139

what determines the color of light?

Back 139

the wavelength, shorter are blue, longer are red

Front 140

what colors does water not absorb?

Back 140

blue and green

Front 141

what do clouds and the sea surface do to light?

Back 141

reflect it

Front 142

what do atmospheric gases do to light?

Back 142

scatter and absorb light

Front 143

scattering

Back 143

occurs as light is bounced between air or water molecules, dust particles, water droplets, or other objects before being absorbed

Front 144

what makes scattering more prevalent

Back 144

more suspended and dissolved particles and the greater density of water

Front 145

absorption

Back 145

governed by the structure of the water molecules, is when molecules absorb light, vibrate, and convert the light into heat.

Front 146

photic zone

Back 146

the thin film of lighted water at the top of the surface zone that extends to 600 meters tops and about 100 meters average.

Front 147

aphotic zone

Back 147

the dark water beneath the photic zone

Front 148

what is light converted to?

Back 148

heat

Front 149

what factors influence the intensity and color of light in the sea?

Back 149

the light intensity and color are influenced by depth (deeper=bluer) and the amount of suspended and dissolved particles. Also if it is cloudy in the atmosphere.

Front 150

intensities being equal, which color of light moves furthest through seawater? Least far? What happens to the energy of light when light is absorbed in seawater?

Back 150

blue wavelengths travel the furthest, red the shortest because red is more likely to be converted to energy than the blue.

Front 151

what factors affect the depth of the photic zone? could there be a photo cline in the ocean?

Back 151

the depth of the photozone is affected by suspended and dissolved sediment. There could be a photo cline if the water went from fresh to salty water.

Front 152

sound

Back 152

a form of energy transmitted by rapid pressure changes in an elastic medium

Front 153

why does sound intensity decrease when traveling through water?

Back 153

spreading, scattering, and absorption.

Front 154

When does the speed of sound increase?

Back 154

as temperature and pressure increase; speed decreases with depth but raises again due to pressure.

Front 155

refraction

Back 155

the bending of waves

Front 156

when does refraction happen

Back 156

when a wave's medium is changed (density) and it isn't at a 90 degree angle to the new medium

Front 157

Which way do sound waves bend?

Back 157

toward layers of lower sound velocity.

Front 158

SOFAR

Back 158

sound fixing and ranging

Front 159

SOFAR Layer

Back 159

the minimum velocity layer

Front 160

active sonar

Back 160

the projection and return through water of short pulses of high frequency sound to search for objects in the ocean

Front 161

side-scan sonar

Back 161

a type of active sonar used for geological investigations, multi beam system.

Front 162

Which frequency of sound has the advantage of efficient travel with least absorption?

Back 162

low frequency

Front 163

which moves faster through the ocean: light or sound?

Back 163

sound travels faster through water

Front 164

how much faster is the speed of sound in water than in air?

Back 164

5 times the speed of sound in air

Front 165

is the speed of sound the same at all ocean depths?

Back 165

the speed of sound is actually fastest at below 5,000 meters or by the sea surface but slows at 1000 meters (SOFAR layer)

Front 166

what is a SOFAR layer?

Back 166

the sound minimum velocity layer where refraction tends to cause the sound wave to remain in the layer. The sounds travel far.

Front 167

how does sonar work? What kinds of sonar systems are used in oceanic research?

Back 167

sonar bounces a frequency off the seabed and the frequency comes back. Multi beam and active sonar.

Front 168

What's so special about water?

Back 168

1. only substance that exists in all states at earths surface, 2. dipolarity makes it a good solvent, 3. heat capacity is very high, 4. ice is less dense than water

Front 169

cation

Back 169

positively charged ion

Front 170

anion

Back 170

negatively charged ion

Front 171

hydration

Back 171

coating of molecules

Front 172

saturation

Back 172

the volume of water can no longer hold more ions

Front 173

solutes

Back 173

dissolved substances in solution

Front 174

dissolved load

Back 174

contributes to the seawater salinity

Front 175

suspended load

Back 175

accumulates as sediment on the seafloor

Front 176

anoxic event

Back 176

no oxygen, mass wipeout of organisms