Geoscience 40 Exam 3

Geostrophic gyres

(geos, "earth"; strophe, "turning"), gyres in balance between the pressure gradient and the Coriolis effect, and their currents are geostrophic currents

Tidal range

(high-water to low-water height difference) varies with basin configuration

Neap tides

(noepa, "hardly disturbed") occur when the moon, earth, and sun form a right angle.

Thermohaline currents

(so named because they depend on density differences caused by variations in water's temperature and salinity) are the slow, deep currents that affect the vast bulk of seawater beneath the pycnocline

In a simplistic system, we think of the solid Earth rotating through an ellipsoidal envelope of ocean water

- 1 full rotation takes the Jersey Shore through 2 bulges every 24 hours - Leading to 2 tides per day

If inputs - outputs - balance is positive

- Accretion of deposition - Coast builds out

What is the earth's velocity halfway between the north pole and the equator in km/hr?

- At 45 degrees North latitude, the circle's radius and circumference are half that of the equator - So speed at 45 degrees North latitude is half that at the equator

Surface occurs when d < L/2

- Bottom of wave hits shore bottom - Bottom of wave slows down from friction - Wave height increases - Wave topples over as a breaker in surf

Tidal drag slows down the earth's reaction

- Cambrian (560 Ma): 425 days - Permian (280 Ma): 395 days - Today (0 Ma): 365 days

Impacts of El Nino

- Climate changes are global - Hot and dry in southeast Asia - Leads to droughts and famine - Wet along west coast of north America - Leads to storms and mudslides

Overfishing

- Marine sources account for 17% of total animal protein consumed by humans - 90% of worldwide stocks of tuna and cod have disappeared - 30% of marine fisheries overexploited - Not enough breeding stock to replenish species - 57% at limit of exploitation

In comparison, the total amount of energy that all humans use in a year is

4.1 x 10^20 Joules.

Antarctic bottom water has been identified as high as

40 degrees north latitude on the Atlantic floor, a journey that has taken some 750 years

Earths circumference

40,010 km

Each hour

430 quintillion Joules of energy from the sun hits the Earth. That's 4.30 x 10^20 Joules.

In theory, the direction of Ekman transport is

90 degrees to the right of the wind direction in the Northern Hemisphere and 9- degrees to the left in the southern hemisphere

La Nina

("the girl"), contrasting colder-than-normal events

The berm (or berms)

An accumulation of sediment that runs parallel to shore and marks the normal limit of sand deposition by wave action

Normal flow

La Nina

Positive numbers mean that the eastern Pacific is warm and negative numbers mean the eastern pacific is cold. Are we in an El nino or La nina today?

La nina

Oceanic eddies can be generated by anything that perturbs

Laminar flow

Interactions between wind and water are complicated by

The fluidity of water

Wavelength

The horizontal distance between two successive crests (or throughs)

Currents

The horizontal drift of ships and the vertical movement of cold water toward the ocean's surface are caused by the mass flow of water

Storms can affect tide height

Meteorological tide

Weather-related alterations are sometimes called

Meteorological tides after their origin

Coriolis deflections in northern and southern hemisphere are

Mirror images of each other

The tidal pattern is called

Mixed (or semidiurnal mixed) if successive high tides or low tides are of significantly different heights throughout the cycle

Equatorial upwelling

Occurs in these westward flowing equatorial surface currents

Atmospheric flow and

Ocean currents are linked

Gravitational forces from moon and sun attract

Ocean waters

Beach nourishment

The importation of sand trapped behind dams (or from other sources) is also only a temporary and very expensive measure

Gravity waves

The inertia of the water causes the crests to overshoot and become troughs

The location of a coast depends

Primarily on global tectonic activity and the volume of water in the ocean

The phenomena of the Southern Oscillation and El Nino are coupled

So the terms are often combined to form the acronym ENSO, for El Nino/Southern Oscillation

In the northern hemisphere, a south-to-north wind leads to an easterly Coriolis deflection

So water piles up against a coast to the east.

First, the wind must be moving faster than the wave crests for energy transfer from air to sea to continue

So, the mean speed, or wind strength, of the wind is clearly important to wind wave development

The primary driver of thermal energy exchange between the ocean and the atmosphere is

Solar radiation

Waves are energy cycles in motion

Sometimes it is useful to think of wave cycles rather than wave distances

As a rule of thumb, if you want to know the weather in state college tomorrow, find out what the weather today is

Chicago

Although the Coriolis effect is weak near the equator (and absent at the equator)

Water moving in the currents on either side of the equator is deflected slightly poleward and replaced by deeper water

Which of the following reflects the time that it takes for a wave cycle to pass?

Wave period

Celerity

Wave speed in distance / time units

During their formation, moderate-sized wind waves in the open ocean exhibit a maximum

Wave steepness (ratio of wave height to wavelength) and angle of their crest

Gradual slope

Waves "spill"

Wave motion can be modeled by sine waves

Waves are generated by disturbing forces and by restoring forces

No matter at what depth water masses are located, the characteristics of each are usually determined by the

Conditions of heating, cooling, evaporation, and dilution that occurred at the ocean surface when the mass was formed

Well-mixed estuaries

Contain differing mixtures of freshwater and salt water through most of their length

Ocean currents are stratified on the basis of density. Are the most dense layers at the ocean surface or the ocean floor

Dense currents are at ocean floor

Winds drive surface currents in oceans. What guides the movement of deep ocean currents?

Density differences

Barrier islands

Depositional coasts can also develop narrow, exposed sandbars that are parallel to but separated from land

Highest tides occur when moon and sun are aligned

Spring tides

When earth, moon, and sun are aligned - biggest tides

Spring tides

Deep ocean currents

Stable stratification of 5 deepwater currents

Storm surges are sometimes even called

Storm tides when the volume of water they force onshore is greatly increased if the surge arrives at the same time as a high tide

Irregular longshore bars

Submerged or exposed accumulations of sand, complete the seaward profile

Laminar flow

Every fluid molecule follows a straight path that is parallel to the boundaries

Turbulent flow

Every fluid molecule follows a very complex path

Equilibrium theory of tides

Explains many characteristics of ocean tides by examining the balance and effects of the forces that allow a planet to stay in a stable orbit around the sun, or the moon to orbit earth.

Jetties or groins

Extensions of rock or other material placed at right angles to longshore drift, to stop the longshore transport of sediments

The result of no thermahaline circulation

Extreme weather variations

Fjord estuaries

Form where glaciers have gouged steep, U-shaped valleys below sea level

A bay mouth bar

Forms when a sand spit closes off a by attaching to a headland adjacent to the bay

Sand spits

Forms where the longshore current slows as it clears a headland and approaches a quiet bay

What is the inverse of period (1/P)

Frequency

Tide-dominated deltas

Freshwater discharge is overpowered by tidal currents that mold sediments into long islands parallel to river flow and perpendicular to the trend of the coast

The Ekman Spiral for winds

From north to south

NASA selected cape Canaveral for rocket launches to

Gain added oomph (=momentum) of southerly location

Wave-dominated deltas

Generally smaller than either tide or river dominated deltas and have a smooth shoreline punctuated by beaches and sand dunes

The effect of Coriolis forces on atmospheric convection generates three convection belts each in the northern and southern atmospheres. From the equator to the north pole, they are:

Hadley, ferrel, polar cells

Air at 30 degrees latitude

Has lost its water to make desert belts

Tidal bore

If conditions are ideal, will form in some inlets (and their associated rivers) exposed to great tidal fluctuation (bara, "wave")

Internal waves

Subsurface waves

Mixed

Successive high and low tides have significantly different heights (double bumps)

The Net Water Transport is the

Sum of all of those currents

Halite

Table salt NaCl

Which two factors are most important in determining the density of ocean water

Temperature and salinity

We sometimes call inertia centrifugal force

The "force" that keeps water against the bottom of a bucket when you swing it overhead in a circle

Why do we not find built-out deltas on the Atlantic coast of the United States?

The Atlantic ocean currents are so strong that they redistribute river sediment before it accumulates in a delta.

Sea islands are composite structures that contain

a firm central core that was part of the mainland when sea level was lower

The net water transport is the

sum of all those currents

Beach scarp

A vertical wall of variable height, often carved by wave action at high tide - to the low-tide mark where the offshore zone begins

The kind of wave is known as an orbital waves

A wave in which particles of water move in closed circles as the wave passes

A beach

A zone of loose particles that covers part or all of ashore

El Nino

- Climate cycle originating in equatorial pacific with global amplification - Likely started at least about 10,000 years ago, based on 13,000 year - old corals - Cayse of major famines in Asia due to failures of monsoonal rains and in south America due to collapse of fishing

In the northern hemisphere, Coriolis Forces lead to

- Clockwise rotation around downwelling and downdrafts - Counter-clockwise rotation around upwelling and updrafts

Consequences of the Ekman spiral

- Coastal winds frictionally move surface layer along coast - Water below upwells to replace advected water - Net flux of upwelled water is away from coastline

The Ekman spiral

- Coriolis forces deflect the surface current created by a northerly wind to the East - And the water beneath the surface current is deflected by Coriolis forces - And the water beneath that current is deflected by Coriolis forces

The ekman spiral

- Coriolis forces deflect the surface current created by a northerly wind to the east - And the water beneath the surface current is deflected by Coriolis forces - The water beneath that current is deflected by Coriolis forces

According to the dynamic theory of tides, since the moon is usually not in the equatorial plane of earth

- Coriolis forces divert tide waves towards the southwest in the southern hemisphere - "no-tide" nodes called amphidromic points occur in each ocean basin

"Boxing Day" Tsunami - Dec. 26, 2004

- Countries most affected: Indonesia, Sri Lanka, Thailand, India - 187,000 dead and 43,000 missing = 230,000 - Second largest earthquake ever recorded --- After 9.5 in Chile on 22 May 1960 - Faulting lasted 500 to 600 seconds --- Longest duration ever observed - Energy released equal to 0.25 gigatons of TNT - Earth's surface oscillated 8-12 inches at epicenter --- About half an inch over whole planet

Earth and moon rotate around this center of mass (like figure-skaters)

- Creates an ocean bulge on the opposite side - Ocean is flung outward because of centrifugal force

3 types of waves defined in terms of relative water depth

- D > L/2 = deep water wave - In between = transitional waves - D < or equal too L/20 = shallow water wave

Waves are defined in terms of depth (d)

- Deep water waves: d > L/2 - Transitional waves: L/2 > d > L/20 - Shallow water waves: L/20 > d

Smoothing rough coastlines

- Deposition in embayment's - Erosion of headlands

ENSO

- El nino - southern oscillation - Variations in the temperature of the equatorial pacific

Waves move energy, not matter

- Energy transfer occurs by circular motions of water molecules, or "orbits" - No net lateral motion of water or seagull as wave passes by

Two ways of describing tidal behavior

- Equilibrium theory - Dynamic theory

If inputs - outputs - balance is negative

- Erosion - Coast gets eaten away

Structures on rocky shores

- Gravel beach - Wave-cut - Sea cave - Tombolo headland - Embayment - Future sea stack - Sea arch - Sea stacks - Wave-cut bench - Pillar

Tidal bulges on Earth result from a combination of

- Gravitational force - Inertia (or centrifugal force)

Three approaches to saving coastal areas

- Hard stabilization --- Structures built to prevent movement of sand along a beach - Beach nourishment - Relocation

Capillary waves coalesce to wind waves given

- High wind velocity - Long wind duration - Long fetch

The greenhouse

- High-energy radiation is transmitted from Sun to Earth - Earth reflects lower energy radiation towards outer space - Lower energy radiation is absorbed by greenhouse gases

The atmosphere - ocean link

- Hot ocean water at the equator evaporates. - Water vapor rises, cools, and falls - Atmospheric convection frictionally induces oceanic circulation

Frequency

- How many wave crests pass a fixed point each second - Measured in cycles per second - So period = 1 / frequency

Period

- How much time passes between each wave crest - Measured in seconds per cycle

Sediment inputs - sediment outputs = balance

- If inputs - outputs - balance is positive - If inputs - outputs - balance is negative - In inputs = outputs - steady state

Dynamic theory of tides

- Includes the effect of continental margins on tides - Predicts that Coriolis forces will move tidal bore in a counterclockwise fashion in northern ocean basins - Rotation occurs about central amphidromic points

Shapes of coastlines controlled by sediment supply

- Inputs - Outgo

The Antarctic circumpolar current

- Is the only current to completely encircle earth - Moves more water than any other current - Has lots of upwelling of nutrients for plankton - Is critical to the THC's global overturning circulation --- Connects the three main ocean basins to the north, thus enabling a truly global circulation --- Permits water masses to undergo large vertical excursions in a stratified ocean without crossing density surfaces

Tsunami at Fukushima Nuclear Plant, Japan

- Known as 2011 Tohoku Earthquake - Magnitude 9.03 earthquake --- Most powerful ever to hit Japan --- Fifth most powerful known - Focal depth of 20 miles - Tsunami reached heights of 133 feet - 15,882 deaths, 6,142 injured, and 2,668 people missing - Three nuclear reactors experienced full melt down - 380,000 buildings collapsed

Exxon Valdez tanker spilled 10.8 million gallons of oil in Prince Willian Sound, Alaska in 1989

- Led to deaths of --- 100,000 and 250,000 seabirds --- 2,800 sea otters --- 300 harbor seals --- 247 bald eagles --- 22 orcas

Oceanic eddies can be generated by anything that perturbs laminar flow

- Local winds channeled by coastal topography - Abrupt changes in wind direction at atmospheric fronts - Oceanic currents at promontories - Water exchange through straits - Instabilities at oceanic current boundaries

Oceanic transgressions are coastal incursions that lead to flooding of landmasses

- Melting of glaciers and ice caps due to global warming - Longshore sediment removal outpaces river inputs - Periods of fast ocean spreading that make shallow seafloor (e.g., Atlantic ocean relative to deep pacific)

Longshore drift

- Migration of sand in direction of wave approach - Beaches as "rivers of sand"

Isostasy

- Mountains and icebergs need deep roots --- Provide buoyant support - As mountains erode or iceberg melts, roots get shallow and boundary shifts upward

Wave motion is oscillatory

- No "net" forward motion of a particle of "parcel" of water - Much like riding on a Ferris wheel

Celerity is related only to water depth (d)

- Not wavelength or period as with deep-water waves - C^2 = g x d, or C = square root of g x d where g is the gravitational acceleration (a constant = 9.8 m/sec^2) and d is depth (in m)

Marine pollution

- Plastic trash pollution on beach of Labuan Bajo (Flores Island) - 5.25 trillion pieces of plastic trash in the world's oceans, and each year, 8 million tons of plastic are added to the count - The deep-water horizon spilled an estimated 210 million gallons of oil in the gulf of Mexico in 2010. - Biomagnification of polychlorinated biphenyls (PCBs) concentrates toxins up the food chain. - New York State discourages children under 15 not to eat > ½ lb of local bluefish or striped bass each week because of PCBs - A 3,000-passenger ship, which today would rank just over medium - size, can produce 21,000 gallons of sewage a day - Mercury is a known neurotoxin that can bioaccumulate in humans causing - Numb or tingling fingers, lips and toes - Developmental delays in children - Muscle and joint pain - Increased risk of heart attack - In the 1950sm an industrial plant in Minimata Bay, Japan discharged methyl mercury directly into the ocean water - Children were born with horrific deformities. 2,265 victims have been officially recognized - Eutrophication - a "green tide" resulting from discharge of nutrients into oceans from agricultural fertilizers that lead to explosive algal blooms - Dead organic matter soaks up oxygen and leads to hypoxia, leading to more fish deaths than any other source

Major control in the moderation of global temperatures

- Poles warmed by equatorial waters - Equator cooled by return of polar waters

Rule of thumb

- Ratio of wavelength to wave height is 7:1 - If L = 70 m, then H = 10 m

Outputs

- Remove of sediment by longshore transport - Removal of sediment by offshore transport

Ocean acidification

- Rising CO2 in the atmosphere leads to the production of carbonic acid and bicarbonate - Rising acidity dissolves calcareous shells of mollusks and corals

Must know both temperature and salinity to compute density of water

- Salinity in measure in psu - Practical salinity units (measured by electrical conductivity) - Essentially the same as parts per thousand (ppt) or per mile

Importance of oceanic gyres

- Salinity is homogenized by oceanic gyres - Nutrients are dispersed by surface circulation

Effects of global warming

- Sea level rise due to glacial melting and water expansion --- 20 inches by 2100? - Agricultural productivity shifts - Changing weather patterns --- More intense hurricanes from higher water temps --- More intense droughts - Crashing of marine ecosystems

Which of the following could explain the oceanic transgression

- Sediment was removed from this area - Sea level has risen

The lighthouse below originally was built on land. Which of the following statements about the picture below is true?

- Shoreline has retreated since the lighthouse was built - Oceanic transgression

The wavelength of tsunami is ~200 km/cycle, and L/20 = 10 km

- Since ocean depth is 4-5 km on average, tsunami are shallow water waves - Travel at 800 km/hr in deep ocean - Wave heights in deep ocean are barely perceptible --- Tsunami peak heights rise to 10 m or more as depth lowers

Examples of waves

- Sound (energy moving through air) - Earthquakes (energy through solid Earth) - Ocean waves (energy moving through liquid)

Melting ice and river inputs dilute salinity

- Summer season - Greenhouse ages

Steep seabed gradients make for plunging waves

- Teahupo'o in French Polynesia is a famous location for big waves - Shallow coral reefs (light blue) fringe the islands --- Corals are surrounded by deep water --- Large depth gradient from sea to beach

Antarctic bottom current

- Temperature : -0.5 degrees Celusis (=31 degrees Fahrenheit) - Salinity: 34.65% - Density: 1.0279 g/cm ^3 - 750 years to reach north Atlantic

Coriolis forces

- The Coriolis forces explain why cyclonic systems in the northern hemisphere rotate in a counter-clockwise sense - Coriolis forces in the northern and southern hemispheres are mirror images - Coriolis forces will occur on any spherical planet that rotates about a fixed axis

Examples of advection

- The chinook winds - warm, dry air that blows from the east flank of the Rockies each spring - The Peru oceanic current, heading northerly along the west coast of Souther America - The flow of the Hudson River from upstate to downstate New York

Why doesn't the moon fly off in outer space

- The orbit of the moon around earth is stable because of the combined actions of gravity and inertia - Inertia + gravity = stable orbit - Inertia of rotating object = centrifugal force

Inputs

- Transport of sediment by currents parallel to shore --- Longshore transport - Transport of sediment by currents perpendicular to the shore --- Onshore transport - River supply

Gulf Stream

- Travels 4.5 miles per hour - Water moves 100 miles per day - Depth: 450 m (1500 ft) - Width: 70 km (43 miles) - Amount of water moved is huge! --- 55 million cubic meters per sec --- 300 times flow of amazon river --- 10^15 calories moved between air and water per second ------- 10^6 times world consumption

Tsunami

- Tsunami are shallow water waves - Tsunami can originate from submarine landslides and meteorite impacts - In the deep ocean, tsunami can travel over 500 miles per hour.

Tidal surges are influenced by positions of moon and sun

- Two springs tides are two neap tides each month - Continental margins experience 1,2, or a mixed number of tides per day

Pycnoclines

- Typically coincide with thermoclines and haloclines - Responsible for ocean stratification - Steepest pycnocline located between warm surface waters and intermediate currents

Fetch

- Uninterrupted distance over which the wind blows without significant change in direction - Largest waves along the Antarctic Circumpolar Current

Tsunami result from

- Volcanic eruptions - Landslides - Meteorite impacts - Earthquakes

How is the walker circulation cell related to the Hadley circulation cell

- Walker circulation currents are perpendicular to Hadley circulation currents

Water is most dense at 4 degrees Celsius

- Water < 4 degrees Celsius is buoyant and rises - Leads to overturning in lakes and oceans - But, salinity can modify behavior

Advection applies to

- Water flow on land or in oceans - Groundwater circulation - Wind

Waves can be periodic over distance and over time

- Wave period measures the amount of time it takes for 2 wave crests to pass a single position - Measured in seconds per cycle

Waves are energy in motion

- Wavelength = distance from crest to crest - Amplitude = distance from still water level to crest (or trough) - Wave height = distance from crest to trough - Celerity = wave velocity (m/sec)

Wind waves travel as "wave trains"

- Wavelengths from 2 cm to 100 m - Gravity not surface tension restores smoothness

Capillary waves are "babies" from which larger waves grow

- Wavelengths less than ~2 cm - Surface tension, not gravity, restores smoothness

Steep slop

- Waves "plunge" - Breakers can form "tubes"

Because atomic or molecular bonds in fluids are much weaker than in solids

- When the top layer of a fluid is pushed, the layer below responds to that push - But the layer below can also respond to other forces

Wind

- Wind patterns affect surface temperatures on the earth - Wind frictionally drives oceanic circulation - Winds are observed on Jupiter and mars

Low - pressure mass

- Winds flow downward around edges toward center due to low pressure - Coriolis forces deflect winds to make counter-clockwise flow - Air collects at center and rises upward - Warm, moist air cools and condenses to rain - Warm moist air cools and makes rain

Coriolis effect

- Winds north from the equator are deflected to the east - Winds from the north pole are deflected to the west

High - pressure mass

- Winds spread outward from margins of air mass - Coriolis forces deflect winds to make clockwise flow - Air deficit at center creates vacuum - Cool, dry air rushes downward and can absorb moisture - Cool dry air descends

Freezing ice removes H2O and increases salinity

- Winter season - Ice ages

El Nino

-mA semi-regular cycle in atmospheric pressure in the western pacific - First described in 1904 by Sir Gilbert Walker - Mathematician in British Colonial Service tasked with predicting famines in south Asia after 1877 catastrophe - Begins with the southern oscillation

Trade winds

0 degrees to 30 degrees Lat and from east to west

Objects launched from the equator have twice the momentum (= mass x velocity) as objects launched from 45 degrees North latitude

0 km/hr

Mid-latitude waters have

1 thermocline but 2 or more haloclines

What is the earth's velocity at the equator in km/hr relative to the north pole

1667 km/hr

How many spring tides occur over one month (approximately)?

2

The tilt of earth's rotational axis relative to the plane of rotation about the Sun is called Earth's obliquity. Which number represents that angular tilt?

23.5 degrees

Earth rotates every

24 hrs about its tilted north-south axis

How long does it take for the Earth-moon system to complete one full rotation

27.3 days

Westerlies

30 degrees to 60 degrees Lat and from west to east

That tilt, or obliquity, is at an angle of

32.5 degrees relative to the plane that Earth orbits the Sun

Today there are 365 days in a year. During the Cambrian (560 Ma), there were 425 days in a year. How many days will make up a year 280 million years in the future?

335 days

The angular velocity (in degrees per hour) is the same over the entire planet

360 degrees divided 24 hr = 15 degrees / hr

For context, the average American home uses

39 billion Joules of electricity each year

At what temperature is water density the highest

4 degrees Celusis

How many ocean-scale gyres do you see?

5

Air mass

A body of air measuring > 1,500 km across with uniform physical characteristics

Estuary

A body of water partially surrounded by land, where freshwater from a river mixes with ocean water

What is the scientific definition of a wave?

A disturbance caused by the movement of energy through some medium (solid, liquid, or gas)

In 1963 the nuclear-powered USS thresher

A fast attack submarine, was lost off the coast of Massachusetts with all hands

Gyre

A flow of current around the periphery of an ocean basin

Lagoon

A long, shallow body of seawater isolated from the ocean - behind these sand dunes

Spilling wave

A more gradually sloping bottom generates a milder, as the crest slides down the face of the wave

Swell

A pack of waves with similar wavelengths and speeds

An inlet

A passage to the ocean - may be cut through a bay mouth bar by tidal action, by water flowing from a river emptying into the bay, or by heavy storm rains

Atmospheric circulation is driven by solar heating

A review of convection

Rip currents

A rip is a strong, localized, and narrow current of water which moves directly away from the shore --- Incorrectly called "rip tides" --- Cut through the lines of breaking waves like a river running out to sea --- Travel up to 8 ft/sec, faster than Olympic swimmer

Tidal wave

A steep wave moving upstream generated by the action of the tide crest in the enclosed area of a river mouth

Slack water

A time of no currents, occurs a short time after high and low tides when the current changes direction

Waves

All of which are disturbances caused by the movement of energy from a source through some medium (solid, liquid, or gas)

Dynamic theory of tides and amphidromic points

Amphidromic tides lead to higher tides in northeastern parts of ocean basins in northern hemisphere

At mid latitudes in the northern hemisphere, cold north-to-south surface currents and upwelling of deep water generally occur

Along the west coasts of continents

Surface currents

About 10% of the water in the world ocean is involved, water flowing horizontally in the uppermost 400 meters (1,300 feet) of the ocean's surface, driven mainly by wind friction

How long are the cycles from one El Nino event to the next

About 3 to 5 years

Dynamic theory

Adds complexities of coastlines, bays, ocean basin geometry, earth deformation, and role of the sun

Why is the Ekman spiral important?

Advection (of wind) can lead to Convection (of ocean water)

Why does water flow around the periphery of the ocean basin instead of spiraling to the center

After all, the Coriolis effect influences any moving mass as long as it moves, so water in a gyre might be expected to curve to the center of the north Atlantic and stop

The net motion of the water down to about 100 meters (330 feet)

After allowance for the summed effects of Ekman spiral (the sum of all the arrows indicating water direction in the effected layers), is known as Ekman transport (or Ekman flow)

What might account for the desert belts at 30 degrees North and South latitude

Air descending at the boundary between the Hadley and Ferrel cells has lost its moisture

Meridional

Aligned with lines of longitude

Newton's first law of inertia

An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force

Advection of water by wind displaces

And allows colder and denser water to rise

Cyclonic flows of low

And high pressure air masses

Some of these caves may eventually form sea arches

And in time collapse to become sea stacks as wave energy continues to erode the cliffs

Continents interrupt ocean water flow

And not every coast sees 2 tides a day

Fastest at the equator

And slowest near the poles

The place where ocean meets land is usually called shore

And the term coast refers to the larger zone affected by the process that occur at this boundary

Contiental landmasses modify the pattern of surface winds

And therefore of oceanic circulation currents

Tracers

Another method, developed for studying thermohaline circulation, senses the presence in seawater of chemical, artificial substances with known histories of production of release

Which of these deepwater currents is the most dense

Antarctic bottom current

AABW

Antarctic bottom water

In the northern hemisphere

Anti-cyclones spin clockwise and have dry high-pressure centers

The popular media and general public tend to label

Any unusually large wave a "tidal wave" regardless of its origin

Plunging waves

Form when waves approach a steeply sloping bottom

River-dominated deltas

Are fed by a strong flow of freshwater and continental sediments, and they form in protected marginal seas

Wind waves

Are gravity waves formed by the transfer of wind energy into water.

The prevailing surface winds between the equator and 30 degrees north latitude

Are known as the "trade winds" and move from east to west

Erosional coasts

Are new coasts in which the dominant processes are those that remove coastal material

Low-energy coasts

Are only infrequently attacked by large waves

Tides

Are periodic, short-term changes in the height of the ocean surface at a particular place, caused by a combination of the gravitational force of the moon and sun and the motion of earth

Depositional coasts

Are steady or growing because of their rate of sediment accumulation or the action of living organisms (such as corals)

Marine erosion is usually most rapid on high-energy coasts

Areas frequently battered by large waves

Remember that Coriolis Effects result from changes in momentum

As objects move towards or away from a rotational axis

It seems strange to refer to tsunami - waves with wavelengths up to 200 kilometers (125 miles)

As shallow water waves

Equilibrium theory

Assumes earth is a smooth ball

This deeper layer of water moves

At an angle to the right of the overlying water

Water vapor condenses to rain

At equator to make rainforest belt

Solar heating of oceans creates

Atmospheric convection cells affected by Coriolis forces

So winds along the coast induce a flow

Away from the coast

Inland of the berm crest, extending to the farthest point where beach sand has been deposited

Backshore

Thermohaline circulation

Because density is largely a function of water temperature and salinity, the movement of water due to differences in density (therme, "heat"; halos, "salt")

Which American Founding Father first discovered the Gulf Stream?

Ben Franklin

The peaked top of the highest berm, is usually the highest point on a beach

Berm crest

Westerly winds from Coriolis forces drive systems to the East

But high-pressure cells move more quickly than low-pressure cells

A sandy beach might form the shore in an area

But the coast or coastal zone includes the marshes, sand dunes, and cliffs just inland of the beach, as well as the sand bars and throughs immediately offshore

Wavelength determines the size of the orbits of water molecules within a wave

But water depth determines the shape of the orbits

In an ocean wave, a ribbon of energy is moving forward at the speed of the wave

But water is not

Nor'easter systems travel west to east

But winds at coast originate from NE

Is pushed

By wind

Two - body systems orbit about a center of mass

Called barycenter is located beneath Earth's surface

Earth's tilt

Called its obliquity, gives rise to seasonality

Wind waves grow from

Capillary waves

If water returning to the ocean - the backwash

Carries back the same amount of material as it delivered, the beach slope will be in equilibrium; that is, the beach will not become larger or steeper

Water from waves washing onto a beach-the swash

Carries particles onshore, increases the beach's slope

Solar tides

Caused by the gravitational and inertial interaction of the sun and earth

Which of the following parameters of a wave is measured in meters per second

Celerity

Yes, there really is a hill near the middle of the North Atlantic

Centered in the area of the Sargasso sea; satellite images provide the evidence

In an ocean eddy that is downwelling in the northern hemisphere, will the rotation be clockwise or counter-clockwise?

Clockwise

Suppose instead of a low-pressure cell with upward drafts of air, we have a high-pressure cells with downdrafts. Is the flow clockwise or counter-clockwise?

Clockwise

What is the sense of rotation if your eyeball looked from the south pole

Clockwise

Coriolis effects are weak near the

Coast

The natural sector of a coastline in which sand input and sand outflow are balanced may be thought of as a

Coastal cell

Wind blowing parallel to shore or offshore can cause

Coastal upwelling

Uplifted terraces

Coastline rises above sea due to jerky uplift by subduction events at active margins

Tectonic motions and isostatic adjustment can change the height and shape of a coast

Coasts can experience uplift as lithospheric plates converge or can be weighted down by masses of ice during a period of widespread glaciation. The continents slowly rise when the ice melts.

Upwelling

Cold ring

What causes Earth's tides?

Combination of gravity and inertia

Oceanic circulation at the surface is

Controlled by prevailing wind directions

Other forces

Coriolis forces

Low tides

Correspond to the throughs, the area between bulges

In the 1890s it was reported that Peruvian fishermen were using the expression

Corriente del Nina ("current of the [Christ] child") to describe the flow; that's where the name, El Nino, came from

Minor gyres in fair north rotate

Counter-clockwise

By analogy with atmospheric cyclonic cells, would an upwelling eddy in the Northern Hemisphere rotate clockwise or counterclockwise

Counterclockwise

High and low pressure cells are

Coupled

The reef is not a single object, but a composite of more than 3,000 individual coral reefs

Covering 350,000 square kilometers (135,000 square miles) - collectively the largest structure made by living organisms on earth

Although the main cause of tides is the gravity of the moon and sun acting on the ocean, the forces that actually generate the tides vary inversely with the

Cube of the distance from Earth's center to the center of the tide-generating object (the moon or sun)

After sinking

Current travels south and connects with Antarctic bottom current

Straight wave fronts evolve to

Curved wave fronts

A storm in the Northern Hemisphere of Jupiter

Cyclone with updrafts

A breaking wave

D<L/2

Fjords

Deep, narrow bays, are often formed by tectonic forces and later modified by glaciers eroding valleys into deep, U-shaped throughs.

Winds from the equator to the north pole are

Deflected east

Winds from the north pole to the equator are

Deflected west

The shoreline in such places is much different from its configuration at the end of the last ice age. The most important of these coastal features

Deltas

Path of individual water molecule is circular in deep water

Diameter of orbits gets smaller with increasing depth

Waves can have the same celerity (meters per sec) but

Different periods (and frequencies)

Ekman transport leads to a

Doming of water in the center of the North Atlantic Gyre

Downwelling

Downward movement

Suppose that a wind from south to north blows along a coast to the east in the northern hemisphere. Will Ekman transport lead to

Downwelling

The Labrador Current off the east coast of Labrador, Canada

Downwelling

Anticyclones

Dry

The water itself may occupy more or less volume as its temperature varies

During times of global warming, seawater expands and occupies more volume, raising sea level

Salt wedge estuaries

Form where a rapidly flowing large river enters the ocean in an area where tidal range is low or moderate

What heat source drives mantle convection

Earth's magnetic field

So Coriolis forces deflect the tide wave towards the ____ in the northern Atlantic

East

West boundary currents in Northern Hemisphere gyres are different from

East boundary currents

Which pattern would you expect for Northern Hemisphere Gyres?

East boundary currents: fast, deep, narrow

The result is a dome shifted to the

East called the Sargasso Sea

Cold-core eddies form in the gulf stream as it meanders

Eastward upon leaving the coast of North America off Cape Hatteras

Water rushing out because of the fall in sea level as tide approaches

Ebb current (the terms ebb tide and flood tide have no technical meaning)

Reverse flow

El Nino

Disturbing force

Energy that causes ocean waves to form

By a depth (d) of ½ the wavelength (L)

Energy transfer (and orbital wave motion) are negligible

Tides are a

Form of wave

All major and minor oceanic gyres in the northern hemisphere rotate clockwise

False

Inertia (or centrifugal force)

Far side from moon

East currents

Fast and deep

West currents

Fast and deep

Dynamic theory of tides

First proposed in 1755 by Laplace, added a fundamental understanding of the problems of fluid motion to Newton's breakthrough in celestial mechanics

Water rushing into an enclosed area because of the rise in sea level as a tide crest approaches

Flood current

Global warming consequences

Flooding of coastal regions by melting of continental ice sheets

Gyre (gyros, "a circle")

Flow, around the periphery of an ocean basin

The west wind drift, or Antarctic circumpolar current, as this exception is called

Flows endlessly eastward around Antartica, driven by powerful, nearly ceaseless westerly winds

Glacial fjords

Glacially carved valley flooded by sea level rise with characteristic U cross-section

Rainforests and deserts reflect

Global atmospheric convection cells

Climate scientists are worried that global warming may terminate thermohaline circulation

Global warming will cause Greenland ice to melt, diluting the thermohaline current

What two forces work together to create an Ekman Spiral and begin the motion of the surface currents

Global winds and Coriolis forces

Which equation describes the relationship for gravity tidal forcing for the Earth and Moon?

Gravitational force for tides = mass of moon / (distance) ^3

Which disturbing force is most responsible for Earth's tides?

Gravity

The coldness at the poles results from

Greater absorption at the poles by thicker slices of atmosphere than at the equator and more concentrated footprint of light beams on the equator than at the poles

Density of H2) increases with lower temperatures until reaching a maximum at 4 degrees Celusis

H bonds hold molecules further apart in solid than in liquid

Thermo

Heat

Costal dunes

Heavy sand and supply and high winds

If a wave gets any higher than this ration for its wavelength, it will break, and excess energy from the wind will be dissipated as turbulence

Hence the whitecaps or cumbers associated with a fully developed sea

Downdrafts

High pressure zones

As a rule of thumb, are high pressure systems associated with rainy or fair weather

High pressure: fair. Low pressure: rainy

A second factor is the length of time the wind duration

High winds that blow only a short time will not generate large waves

The shape of a gyre in the absence of Coriolis Effects

Highly Symmetric

But Coriolis effects make gyres

Highly asymmetric

Forced waves

Huge shallow - water waves are never free of the forces that cause

Equilibrium theory

In his pioneering work that described the motion of planets, moons, and all other bodies in gravitational fields, Issaac Newton developed a gravitational mode of the tides

Smaller gyres at poles and

In north Indian ocean

Does the ACC flow

In the direction of Earth's rotation

Ocean wave orbitals dimmish with

Increasing depth

The wind-driven horizontal movement of water can sometimes

Induce vertical moment in surface water (wind-induced vertical circulation)

Analogy with skaters again

Inertia (centrifugal force) leads to oceanic bulge opposite Moon and Sun

Breakwater

Interrupts the progress of waves to the beach, weakening the longshore current and allowing sand to accumulate there

Onrushing water disappears

Into a beach made of coarse particles, so little water is left to rush down the slope, thereby minimizing the transport of sediments back to the ocean

Wave crest

Is the highest part of the wave above average water level

The gulf stream

Is the largest of the western boundary currents

A fully developed sea

Is the maximum wave size theoretically possible for a wind of a specific strength, duration, and fetch

The surf zone

Is the region between the breaking waves and the shore

Wave through

Is the valley between wave crests below average water level

The card beneath

It in the deck feels this card's movement and begins to move

The amount of water in the world ocean can vary. Sea level is lower during periods of global glaciation (ice ages) because some of the water that was previously in the ocean becomes frozen in land-based glaciers

It is higher during warm periods, when water from melting glaciers is released back into the ocean. Periods of abundant volcanic outgassing can also add water to the ocean and raise sea level

Remember, the second card in the deck cannot feel the wind directly

It is only moving in response to the movement of the topmost card

Are the waves in the southern ocean likely to be highest in January or July

July

Smooth, nearly level wave - cut platforms can be found

Just offshore, which marks the submerged limit of rapid marine erosion

What is the equation for wavelength (L) in terms of period and celerity

L = C x P

Wave bottom slows when depth

L/2

With increasing salinity, the density of water increases

Linearly

Weather reflects

Local (geographically smaller) atmospheric convection cells

Local changes are bound to occur, and two other factors produce variations in

Local sea level

Sediments are also transported in the surf zone in a

Long shore current

Tsunami

Long-wavelengths, shallow-water progressive waves caused by the rapid displacement of ocean water; a descriptive Japanese term combining tsu ("harbor") with nami ("wave")

The movement of sediment (usually sand) along the coast, driven by wave action

Longshore drift

Below the low-tide mark, wave action turbulent backwash, and longshore currents excavate, parallel to shore

Longshore through

Would you expect high pressure or low pressure zones at the boundary between the polar and Ferrel cells

Low pressure

Rising air creates

Low pressure at the surface

Updrafts

Low pressure zones

In the north hemisphere

Low-pressure cyclones with rising air rotate counter-clockwise

Storms rotating counter-clockwise in the Northern Hemisphere are

Low-pressure cyclones with updrafts

Think of the figure-skaters' joined hands as gravity (if they lost their grip, they'd start sliding apart as a result of inertia, or the centrifugal force)

M is called the Center of Mass of this rotating system

Plate tectonics is driven by

Mantle convection

This results in a stair - step formation along the coast known as a wave-cut terrace

Marine terrace

Gravitational force for tides is proportional to

Mass of planet / (distance)^3

Momentum is

Mass x velocity and is maximized at the equator

On coasts with mixed tides, the zero tide level is the average level of the lower of the two daily low tides

Mean lower low water or MLLW

Thermohaline circulation

Movement of ocean water caused by density differences due to temperature and salinity

Importance of oceanic gyres

Movement of water from equator to poles transfers heat energy from equator to poles

Lowest tides occur when moon and sun are at 90 degrees

Neap tides

When earth + moon alignment is perpendicular to earth + sun alignment - smallest tides

Neap tides

Gravitational force

Near side to moon

Is the Coriolis effect more pronounced for objects near the equator or near the poles

Near the poles

Is the change in velocity higher near the equator or near the poles?

Near the poles

Waves slow down

Near the shore

Do you see a lot of change in salinity as the seasons pass based on the bottom scroll?

No

If inputs = outputs - steady-state

No change in coast position

Is the ice in icebergs salty

No! The formation of ice takes H2O out of seawater and leaves NaCl behind, making the water saltier and denser

NADW

North Atlantic deep water

These channels allow the cold, dense water formed in the Arctic to flow into North Atlantic to form

North Atlantic deep water

Cold waters upwell off the coast of California due to Ekman transport. What must the prevailing wind direction be here?

North to South

The Antarctic circumpolar current

Not considered a gyre because the circulation encompasses a continent

Because of the urging of the Coriolis effect

Note that east-west currents in the North Atlantic gyre flow to the right of the drinking winds

Between 20 million and 50 million cubic meters

Of this brine from every second

The pacific coast of the United States has a mixed tidal pattern

Often a higher high tide, followed by a lower low tide, a lower high tide, and a higher low tide each lunar day

The earth-moon system revolves

Once a month - (27.3 days) around the system's center of mass

Diurnal

Once/day

Others have diurnal (daily) tides

One high and one low

Interference

One wave doesn't crawl over the others when they meet; instead, they add to or subtract from one another

Deep water waves are defined as waves traveling over depths that are what multiple of the wavelength (L)?

One-half the wavelength (2L)

Doming is visible in NASA satellite images

Only 2 meters higher than surrounding ocean

The planets lie in nearly the same

Orbital plane, or ecliptic

In the US, low-pressure cyclonic cells often originate

Originate from warm moist air originating in the Gulf of Mexico

Wind and currents, storm surges, an El Nino or La Nina event

Other effects of water in motion can force water against the shore or draw it away

Sun, moon, and earth

Parallel alignment twice per month --- Spring tides Perpendicular alignment twice per month --- Neap tides

Coastal plains and sandbars

Passive continental margins

Waves also are classified in terms of their

Period

Waves are defined in terms of their

Period

Paradoxically, net water flow over the water column may be

Perpendicular to the wind direction

Coriolis effects are strong near the

Poles

Tsunami arrive at ~ 50 km/hr as wall of water 10 m high

Preceded by sharp pullback of water

The process of wave separation, or dispersion

Produces the familiar smooth undulation of the ocean surface called swell

Wave trains

Progressing groups of swell with the same origin and wavelength

Because the wave form moves forward, these waves are a type of

Progressive wave

The balance of wind energy, friction, the Coriolis effect, and the pressure gradient

Propels gyres and holds them along the edges of ocean basins

When a truck passes you at high speech, after it passes, the pressure difference

Pulls you towards it

Cyclones

Rainy

The bending of waves as they shoal (approach shallow water) is called

Refraction

Both the rate of rotation and the degree of tilt are

Remnants from the collision with the Mars-sized object that made the moon

Global heating

Rising CO2 in the atmosphere leads to the capture of infrared radiation, leading increased temperatures

River dominated

River builds out into ocean from coastline

This is an aerial photograph of the Yellow River delta in China

River dominated

Swampy deltas

Rivers deliver high sediment loads

Is salty water more or less dense than freshwater

Salt water is more dense and will sink in fresh water

Haline

Saltiness

The parade of wave cuts

Sea caves into the cliffs at local zones of weakness in rocks

How does the formation of sea-ice in the winter influence seawater density

Sea-ice formation increases seawater density

Foreshore

Seaward of the berm crest, is the active zone of the beach, washed by waves during the daily rise and fall of the tides

Shapes of coastlines controlled by sediment supply

Sediment inputs - sediment outputs = balance

If the wavelength of a tsunami is in the range of 200 km/cycle, and the ocean depth on average is 4 km, then tsunami must always be

Shallow-water waves

Which scientist first proposed an atmospheric convection cell within the Pacific Equatorial Plane

Sir Gilbert Walker

Sea cliffs

Slope abruptly from land into ocean, their steepness usually resulting from the collapse of undercut notches

East currents

Slow and diffuse

West currents

Slow and diffuse

So, do waves speed up or slow down as they reach shallower water depths

Slow down

Wave refraction

Slowing a bending of waves in shallow water

Over time, do offshore currents smooth or roughen rocky shorelines

Smooth

The turbulent mass of agitated water rushing shoreward during and after the break is known as

Surf

Constructive and destructive interferences

Surf beat

Atmospheric convection cells generate

Surface winds from high to low pressure

The best course of action to take when you are caught swimming in a rip is to

Swim parallel to the shore

Why does the Gulf Stream sink in the Labrador Sea

The Gulf Stream gets saltier and colder as it travels to the northern Atlantic Ocean

Storm surge

The abrupt bulge of water driven ashore by a tropical cyclone (hurricane) or frontal storm

An archer stands at the north pole and aims his arrow directly at a target on the equator. What effect will the earth's rotation have on the path of the arrow after it is shot?

The arrow will travel to the west of the target.

Suppose we spray the bottom of a glass of water with liquid nitrogen (temperature = - 196 degrees Celsius) and create the temperature profile indicated. What would happen to the water at the base of the glass?

The bottom-most layer will rise

Front

The boundary between air masses

High tides

The bulges are the crests of the planet - sized waves

Destructive interference

The cancelation effect of subtraction, not because of harm to lives or property but because wave interference destroys or cancels waves

CE

The center of earth - are the inward pull of gravity and the outward - moving tendency of inertia exactly equal and opposite

Southern oscillation

The change in atmospheric pressure (and this in wind direction)

Restoring force

The dominant force that returns the water surface to flatness after a wave has formed in it

A modification proposed by Pierre - Simon Laplace about a century later

The dynamic theory, takes into account the speed of the long-wavelength tide wave in relatively shallow water, the presence of interfering continents, and the circular movement of rhythmic back-and-forth rocking of water in ocean basins

If the rotational axis of the earth were not tilted relative to its orbital plane around the sun, then

The earth would not experience seasons

In the northern hemisphere, winds from te equator to the north are deflected to

The east

Westward intensification

The effect on currents flow

Coupling between wind and solids is pretty straightforward

The entire solid moves in the direction of the wind

The poles are coldest

The equator is hottest

Ocean waves are classified by disturbing force that creates them

The extent to which the disturbing force continues to influence the waves once they are formed, the restoring force that tries to flatten them, and their wavelength

Which statement concerning the movement of water in waves on the open ocean is correct?

Water molecules follow a circular path as the wave passes

Spring tides

The large tides caused by the linear alignment of the sun, earth, and moon "to move quickly springen

Eddies

The looping meanders sometimes connect to form turbulent rings, that trap cold or warm water in their centers and then separate from the main flow

What is the definition of laminar flow

The molecules within the fluid flow in straight lines

Active coasts near the leading edge of moving continental plates, were found to be fundamentally different from

The more passive coasts near trailing edges

Antarctic bottom water

The most distinctive of the deep-water masses, is characterized by a salinity of 34.65%, a temperature of 0.5 degrees Celius (31 degrees Fahrenheit), and a density of 1.0279 grams per cubic centimeter

Argo system

The most successful, a vast sampling net-work of nearly 4,000 independently drifting sensors

Amphidromic point

The node (or nodes) near the center of an ocean basin (amphi, "around"; dromas, "running")

Wave frequency

The number of waves passing a fixed point per second

Deflections due to the Coriolis effect in the northern hemisphere are

The opposite of those in the southern hemisphere

Tractive forces

The outward - flinging force of inertia and the inward-pulling force of gravity

Ekman spiral

The resulting situation after the Swedish oceanographer who worked out of the mathematics involved

Deep water follows

The same trends

Distributaries

The split ends of the river - in a characteristic bird's foot shape

Which is the best definition of inertia

The tendency for a moving object to keep moving (or for a resting object to stay at rest)

Wave period

The time it takes for a wave to move a distance of one wavelength

Advection

The transfer of heat or matter horizontally by fluid flow

Sverdrup (SV)

The unit used to express Volume transport in ocean currents, named in honor of Harald Sverdrup, one of the last century's pioneering oceanographers.

When higher sea level returned

The valleys were flooded, or drowned, with seawater

Wave height

The vertical distance between a wave crest and the adjacent through

The term spiral is somewhat misleading

The water itself does not spiral downward in a whirlpool-like motion like water going down a drain

To turn further right

The water would have to move uphill against the pressure gradient (and in defiance of gravity), but to turn left in response to the pressure gradient would defy the Coriolis effect

Water is moving faster than

The wave

On coasts with diurnal and semidiurnal tides

The zero tide level is the average level of all low tides (mean low water, MLW)

Vertical circulation

Thermohaline conveyer belt

King tides

These very high tides are sometimes

After they are formed, wind waves and tsunami are free waves

They are no longer being acted upon the force that created them and do not require a maintaining force to keep them in motion

Shallow-water waves

This behavior of tides is only one variation from the ideal that the dynamic theory explains

Because earth's mass is 81 times that of the moon

This common center of mass is located not in space but 1,650 kilometers (1,023 miles) inside earth

The volume of the ocean's "container" may vary, high rates of seafloor spreading are associated with the expansion in volume of the oceanic ridges

This expansion displaces the ocean's water, which climbs higher on the edges of the continents. Sediments shed by the continents during periods of rapid erosion can also decrease the volume of ocean basins and raise sea level

The restoring force for very small capillary waves

Those with wavelengths less than 1.73 centimeters (0.68 inch) - is cohesion, where as for larger waves, gravity pulls the crests downward

Running at high speed

Thresher may have encountered an internal wave and been forced beyond its test depth

The moon and sun create

Tidal bulge on Earth through differences in gravitational attraction on close and far sides of Earth

The rise or fall in sea level as a tide crest approaches and passes will cause a

Tidal current of water to flow into or out of bays and harbors

The reference level to which tidal height is compared is called the

Tidal datum

Tide-dominated

Tidal flow landward and seaward causes channels and islands perpendicular to coast

Weaker effect for Sun results from farther distance from the Earth

Tidal forcing varies as cube of distance

Lunar tide

Tides caused by gravitational and inertial interaction of the moon and Earth, complete their cycle in a tidal day (also called a lunar day)

Astronomical tides

Tides caused by inertia and the gravitational force of the sun and moon

Surface water

To a depth of about 200 meters (660 feet)

Intermediate water

To about 1,500 meters (5,000 feet)

The key to understanding the equilibrium theory of tides is

To see Earth turning beneath these bulges

Central water

To the bottom of the main thermocline (which varies with latitude)

Will the Coriolis effect deflect a rocket launched north from the equator to the east or the west

To the east

Southern hemisphere currents flow

To the left

Because of the Coriolis effect Northern hemisphere surface currents flow

To the right of the wind direction

If the island is close to shore, a bridge of sediments may accumulate to connect the island to the mainland

Tombolo

The maps above depict the development of the western interior seaway in the united states during the cretaceous period, splitting the US mainland in two. Does the period from 105 Ma to 85 Ma represent a time of oceanic

Transgression

The transfer of energy from water particle to water particle in these circular paths, or orbits

Transmits wave energy across the ocean surface and causes the wave form to move

Mangroves

Trees that can grow in salt water

The momentum of objects at Earth's equator is greater than the momentum of objects located close to the Earth's poles.

True

Seismic sea waves

Tsunami caused by the sudden, vertical movement of earth along faults (the same forces that cause earthquakes

Semidiurnal

Twice/day

Some coastlines experience semidiurnal (twice daily) tides

Two high tides and two low tides of nearly equal level each lunar day

The gull moves in circles

Up and forward as the tops of the waves move to its position, down and backward as the tops move past

Tidal reach measures the vertical distance between low and high tide

Up to 16m at Bay of Fundy

The shape of a coast is a product of many processes

Uplift and subsidence, the wearing down of land by erosion, and the redistribution of material by sediment transport and deposition

Upwelling

Upward movement of water, the process brings deep, cold, usually nutrient-laden water toward the surface

The Canary Current along the west coast of Africa.

Upwelling

The Gulf Stream along the East Coast of the US.

Upwelling

The distance velocity (in km or miles per hour)

Varies with location

Dissolved sodium chloride (NaCl) also changes water density. Where did the chlorine in seawater come from?

Volcanic emissions

Downwelling

Warm ring

El nino

Warm water to the east

La nina

Warm water to the west

Deep water

Water below intermediate water but not contact with the bottom, to a depth of about 4,000 meters (13,100 feet)

Bottom water

Water in contact with the seafloor

Shallow-water waves

Waves in water shallower than 1/20th their original wavelength

Deep-water waves

Waves moving through water deeper than half their wavelength

Wave-dominated

Waves push sediment back onto coastline

Tidal forcing by Sun is 46% as strong as tidal forcing by Moon

Weaker but not insignificant

Classic inverted "V" forms

When cold front from west swoops in on cyclonic warm front to east

Dynamic theory of tides and amphidromic points

When the moon is north of the equator, it pulls the bulge of ocean water to the north

Distinct from convection

Which involved the vertical transfer of heat and/or matter

Mean seal level

Which is the height of the ocean surface averaged over a few years' time

This is due to wave refraction

Which results in wave energy being focused onto headlands and away from bays

Lateral movement of air from high pressure to low pressure is called

Wind

Why does wind blowing across the surface of water lead to upwelling?

Wind advects surface water, and water upwells to maintain isostatic balance

Wind strength

Wind must be moving faster than the wave crests for energy transfer to continue

Tsunami (not Tsunamis) are not

Wind waves or tide waves

Surface currents

Wind-driven movements of water at or near the ocean's surface

Upwelling occurs when

Winds blow along the west coast of a continent in the northern hemisphere

Wind duration

Winds that blow for a short time will not generate large waves

Wave heights are highest at the acc

Winds travel without obstruction by continents

Rogue wave

Would be much larger than any notice before or after, and it would be higher than the theoretical maximum wave capable of being sustained in a fully developed sea

Pycnocline

Zone of major density change

Halocline

Zone of major salinity change

Thermocline

Zone of major temperature change

Coriolis forces result from

differences in momentum between the equator and the poles

Gravity and inertia lead to

oceanic bulges on the sides nearest and farthest from the moon

Three of these factors are responsible for eustatic change

or variations in sea level that can be measured all over the world ocean, whereas the other two influence local sea level

Deeper estuaries exposed to similar tidal conditions but greater river flow become

partially mixed estuaries

There are five large western boundary currents; the gulf stream (in the North Atlantic), the Japan or Kuroshio Current (in the North Pacific)

the Brazil current (in the South Atlantic), the Agulhas Current (in the Indian Ocean), and the east Australian Current (in the south pacific)

Is the additive formation of large crests or deep throughs, the size of

throughs, the size of which exceeds the size of each participating wave

The third factor is the uninterrupted distance over

which the wind blows without significant change in direction, the fetch