Geo One Test 3

List the evidence that exists to support the idea that the Mediterranea Sea completely dried up in the geologic past.

Thick salt deposits exist that indicate that a huge sea dried up years ago and then refilled. 4000 meters of salt deposits can be found. There are fossil evidence, changing climate, and deep notches in the surrounding river valley.

Describe the tectonic and depositional processes causing subsidence along the Atlantic Coast.

Most of the cost is exposed to storm waves from the open ocean Tidal ranges get bigger as you go north Sedimentary rock Glaciers affect everything north of New York

Why is it more likely that a tsunami will be generated by faults beneath the ocean along with vertical rather than horizontal movement has occurred?

Think about it: Vertical movement of the seafloor causes vertical movement of the water above it, generating large waves. (Horizontal or transform faults—rocks sliding past each other—do not generally move water up or down hence are not usually tsunamigenic.)

What atmospheric pressure is associated with the centers of subtropical gyres? With subpolar gyres? Explain why the subtropical gyres in the Northern Hemisphere move in a clockwise fashion while the subpolar gyres rotate in a counterclockwise pattern.

Subtropical: high pressure Subpolar: low pressure Currents that flow eastward as a result of the prevailing westerlies eventually move into subpolar latitudes, here they are driven into a western direction by the polar easterlies thus changing the direction in which they rotate.

Describe differences between summertime and wintertime beaches. Explain why the differences occur.

Summer beaches: light waves, sand moves landward, wide berm, causes build up of sand Winter beaches: stronger waves, sand moves seaward, offshore bars (beaches have less sand b/c it has eroded

What would the pattern on ocean surface currents look like if there were no continents on Earth?

They would look like wind belts.

Discuss factors the help produce the world's greatest tidal range in the Bay of Fundy.

A combination of a shallow sloping bottom, a split in the bay which makes water funnel north (coriolis effect) and a buildup of tidal energy in the north end of the bay.

Describe all parts of a beach compartment. What will happen when dams are built across all of the rivers that supply sand to the beach?

A series of rivers that supply sand to the beach, the beach itself where sand is moving due to longshore transport, and offshore submarine canyons where sand is drained away from the beach (so primarily rivers and coastal erosion supply sand). If dams are built there will be no more beach.

Diagram and discuss how Ekman transport produces the "hill" of water within subtropical gyres that cause geostrophic current flow. As a starting place on the diagram, use the wind belts (the trade winds and the prevailing winds).

A theoretical consideration of the effect of a steady wind blowing over an ocean of unlimited depth and breadth and of uniform viscosity. The result is a surface flow at 45 degrees to the right of the wind in the Northern Hemisphere. Water at increasing depth below the surface will drift in directions increasingly more slowly and to the right until about 100m depth, it may move in direction opposite to that of the wind.

While shopping in a surf shop, you overhear some surfing enthusiast mention they they would really like to ride to curling wave of a tidal wave at least once in their life, because it is a single break wake of enormous height. What would you say to these surfers?

A tsunami does not consist of a single breaking wave and that when the crest of a tsunami arrives there is a single surge of ocean water onshore.

Discuss several different ways in which waves form. How are most ocean waves generated?

All ocean waves begin by disturbances caused by releases of energy. Releases of energy include wind, movement of fluids of different densities, mass movement into the ocean underwater sea floor movements, gravitational pull, and human activities in the ocean. Most waves are generated by wind.

Describe the relationship between surface circulation and monsoon winds in the Bay of Bengal.

During the SW monsoon, a clockwise rotation is set within the Bay. This circulation is accompanied by an upwelling along the East Indian coast. The NW monsoon causes the direction of circulation to switch to counterclockwise.

The Antarctic Intermediate Water can be identified throughout much of the South Atlantic based on its temperature, salinity, and dissolved oxygen content. Why is it colder and less salty- and contain more oxygen- than the surface-water mass above it and the North Atlantic Deep Water below it?

Antarctic Intermediate Water (AIW) forms at the Antarctic convergence. It is cold because it originates around 60oS, it is less salty because this is an area of high precipitation, and it has high dissolved oxygen because it is cold. [As you know from experiences with cold and warm soda, cold water can contain more dissolved gases than warmer water.] North Atlantic Deep Water (NADW) is far from its source (in the North Atlantic) so that the oxygen once contained within it has been used by respiration, decomposition, and mineral oxidation. NADW is saltier because of its complex mixing with Gulf Stream, Norwegian Sea, and Mediterranean waters in the North Atlantic. AAIW and NADW have about the same temperatures. AAIW is denser than the surface water above it, so it is cooler than surface water.

Explain why the maximum tidal range (spring tide) occurs during new and full moon phases and the minimum tidal range (neap tide) at first-quarter and third-quarter moons.

During spring tides all of the forces are in alignment and that is why it is the highest. During neap tides the forces are opposing and that's why they aren't that high.

Why is a lunar day 24 hours 50 minutes long, while a solar day is 24 hours long?

Because as the Earth rotates around the sun, the moon is rotating around the Earth, and it takes an additional 50 min for the Earth to catch up to the moon.

Why does the direction of longshore current sometime reverse in direction? Along both U.S. coasts, what is the primary direction of annual longshore current?

Because the direction from which the wave approaches changes seasonally. Southward along both the Atlantic and Pacific shores of the United States.

Explain why the Sun's influence on Earth's tides is only 46% that of the Moon's, even though the Sun is so much more massive than the Moon.

Because the tide generating force of the moon is much bigger than the sun, the moon is closer to the Earth than the sun.

Why is the development of internal waves likely within the pycnocline?

Because the waves travel along the boundary between water of different density and pycnoclines are locations with big changes in density

Describe the circulation between the Atlantic Ocean and the Mediterranean Sea, and explain how and why it differs from estuarine circulation.

Circulation caused by dry, intense heat of the middle east. High rate of evaporation( High inflow of Atlantic ocean water to replace evaporated water). During winter, this water sings to form the Mediterranean Intermediate Water = High salinity, this water returns to Atlantic ocean as Subsurface Flow

Based on their origin, draw and describe the four major classes of estuaries.

Coastal Plain Estuary: former river valley now flooded with seawater Ex: Chesapeake & Delaware Bays Fjord: former glaciated valley now flooded with seawater. Ex: Alaskan Fjord Bar-Built Estuary:lagoon separated from ocean by sand bar or barrier island.Ex: New Jersey Coast Tectonic Estuary: Faulted or folded down-dropped area now flooded with ocean. EX: San Francisco Bay (dropping b/t two faults)

List and discuss four factors that influence the classification of a coast as either erosional or depositional

Coastal bedrock: stronger bedrock is harder to erode Tidal range: how much wave action is it getting Isostatic subsidence: is sea level rising or lowering Eustatic sea level change: same as above.

Describe the number of high and low tides in a lunar day, the period, and any inequality of the following tidal patterns: diurnal, semidiurnal, and mixed.

Diurnal tidal pattern: single high and low tide each day, tidal period of 24 hours and 50 mins Semidiurnal tidal pattern: 2 high and 2 low tides each day, period is 12 hours and 25 mins. Mixed tidal pattern: mix of both tidal patterns

How often do El Nino events occur? Using Figure 20, determine how many years since 1950 have been El Nino years. Has the pattern of El Nino events occurred at regular intervals?

El Niño conditions occur every 2 to 10 years (average about 5). From 1950 to 2000 there were 12 major El Niño events, or one event every four years. El Niño events are irregular.

What ocean depth would be required for a tsunami with a wavelength of 220 kilometers (136) miles) to travel as a deep water wave? Is it possible that such a wave could become a deep-water wave any place in the world ocean? Explain.

For a tsunami with a wavelength of 220 km to travel as a deep-water wave, water would need to show orbital motion as far down as the wave base (half the wavelength down.) The ocean would have to be 110 km (68 miles) deep. The Mariana Trench is only one tenth of that (11 km / 6.8 miles deep) so no, a tsunami can never be a deep-water wave.

Draw or describe several different oceanographic conditions that produce upwelling.

If surface waters are moved away from each other or away from a coastline, upwelling results.

Define the terms nodes and antinode as they relate to standing waves.

In standing waves, antinodes are crests and troughs where water moves vertically (up and down) whereas nodes are locations where there is no vertical movement. Maximum horizontal motion occurs beneath the node.

How if La Nina different from El Nino? Describe the pattern of La Nina events in relation to El Nino since 1950 (see Figure 20).

La Niña events are the opposite of El Niño events. Pacific Warm Pool moves westward across the equatorial Pacific. Thermocline is shallower in eastern Pacific (enhanced upwelling). Enhanced upwelling results in high biologic productivity (more marine life) etc

What factors lead to a wide seasonal range of salinity in Laguna Madre?

Laguna Madre along the Texas coast formed about 6000 years ago. Large temperature & salinity range, Hypersaline causes this wide range (High evaporation generally keeps salinity < 50 parts-per-thousand). Marsh replaced by open beach sand on Padre Island

Discuss longitudinal, transverse, and orbital wave phenomena, including the state of matter in which each can transmit energy.

Longitudinal (push-pull, compression, back/forth) waves transmit energy through all states of matter by alternately compressing and decompressing particles in the direction of waveform motion. (Sound waves move through all states of matter.) Transverse (side-to-side) waves transmit energy through solids (earth's crust!) and move particles up and down or side to side (at right angles to wave movement). Orbital waves transmit energy through fluids (along interface) and move particles in circular orbits.

Explain how the tsunami warning in the Pacific Ocean works. Why must the tsunami be verified at the closest tide recording station?

NOAA operates two centers: The PTWC (Pacific Tsunami Warning Center based in Ewa Beach, Hawaii), and the WCATWC (West Coast and Alaska Tsunami Warning Center, based in Palmer Alaska...40 mi NE of Anchorage...just 10 mi E of Wasilla). At these centers scientists observe seismic records for tsunamigenic earthquakes. Over 50 tide-measuring stations monitor unusual wave activity. Scientists look for unusual wave activity at the station nearest the epicenter in order to verify that the earthquake had sufficient intensity and vertical displacement to generate a tsunami. NOTE: The PTWC will ONLY issue a warning if a tsunami is ENROUTE AND WILL HIT. This eliminates false alarms. (Also: Even though its name says Pacific, the PTWC is currently serving the Caribbean. PTWC coverage of the Indian Ocean has been discontinued.)

Explain why Gulf Stream eddies that develop northeast of the Gulf Stream rotate clockwise and have warm- water cores, whereas those that develop to the southwest rotate counterclockwise and have cold water cores.

OMIT:Whether it is a warm ring or a cool ring, whether it rotates clockwise or counterclockwise is a function of which meander is pinched off. In other words: The three sides of the Gulf Stream meanders that bulge to the right (colder water bulging into warmer water) flow SE then NE then NW. If the last side of that meander - SW - severs the meander, the severed cold water loop simply continues rotating counter-clockwise. The reverse is true for the warmer water bulging left of the Gulf Stream NW then NE then SE. If that last side - again SW - severs the meander, that warm water ring simply continues the clockwise rotation started in the meander.

Describe changes in oceanographic phenomena, including Walker Circulation, the Pacific warm pool, trade winds, equatorial countercurrent flow, upwelling/downwelling, and abundance of marine life, that occur during and El Nino event. What are some global effects of El Nino?

Pacific Warm Pool moves eastward across the equatorial Pacific, toward Peru. Equatorial Countercurrent is faster. Thermocline is deepened in eastern Pacific (reduced upwelling. Reduced upwelling results in low biologic productivity (less marine life). Sea level rises along the eastern Pacific. Velocity of southeast trade winds decreases (or winds reverse). There is low atmospheric pressure over South America, high pressure over Indonesia. Weaker Walker Circulation Cell results in slower trade winds. Global effects: changes in wind circulation (direction and vigor) changes in patterns of precipitation changes in atmospheric pressure changes in intensity of tropical cyclones

Define the characteristics of the two major categories of Shepard's classification of coasts, and list the subcategories of each.

Primary Coast: younger coasts that been formed by nonmarine processes Land erosion coasts Subaerial depositional coasts Volcanic coasts Coasts shaped by Earth movements Ice coasts Secondary Coasts: aged to the point where physical and/or biological marine processes dominate the character of the coast. Wave erosion Marine deposition coasts (prograded by wave, currents) Coast formed by biological activity

Using examples, explain how wave refraction is different from wave reflection.

Refraction: waves approaching a shore are bent so that the wave fronts approach nearly parallel to shoreline Reflection: waves approaching a very steep shore (or wall) are bounced back from that wall. Reflected waves may constructively interfere with oncoming waves.

Discuss the differences between rotary and reverse tidal currents.

Rotary: moves counter clockwise Reverse: a rotary current that has changed direction and now move in and out

For coastal oceans where deep mixing does not occur, discuss the effect that offshore winds and freshwater runoff will have on salinity distribution. How will the winter and summer seasons affect the temperature distribution in the water column?

Salinity is variable due to: Freshwater runoff: can produce a well-defined halocline Mixing by tides: Water may be isohaline Winds (offshore): Dry offshore winds cause a high rate of evaporation and thus high surface salinities In the middle latitudes, coastal surface water is significantly warmed during the summer and cooled during the winter (Temperature variable

Name the two types of coastal wetland environments and the latitude ranges where each will likely develop. How do wetlands contribute to the biology of the oceans and the cleansing of polluted river water?

Salt Marshes: b/t 30 & 65 degrees, grasses and low-lying plants (halophytic= salt plant) Mangrove Swamps: restricted to tropical regions(> 30 deg. lat.), trees & shrubs & palms Contribute to biology and ease pollution: Nurseries, feeding grounds for commercially important marine animals Efficiently cleanse polluted water Absorb water from coastal flooding Protect shores from wave erosion

Describe how coastal upwelling in the Gulf of California is related to seasonal winds.

Seasonal winds control the surface circulation there. Low pressure atmospheric system in the summer drive winds that drive surface water from the Pacific into the Gulf. This causes upwelling along the steep rocky Baja coast.

Discuss factors that cause the surface salinity of Chesapeake Bay to be be greater along its east side, and why periods of summer anoxia in deep water are becoming increasingly severe with time.

Slightly stratified, Seasonal changes in salinity, temp., dissolved oxygen, Anoxic conditions below pycnocline in summer, lack of oxygen, Major kills of commercially important marine animals, increased agricultural inputs.

What variables affect the speed of longshore currents?

Speeds increase as beach slope increases, as the angle at which breakers arrive at the beach increase, as wave height increases, and as wave frequency increases.

Describe the three different types of breakers and indicate the slope of the beach that produces the types. How is the energy of the wave distributed differently within the surf zone by the three types of breakers?

Spilling breaker: gentle beach slope, breaker less steep, energy dissipated over longer length Plunging breaker: steep beach slope, breaker curls, energy dissipated over shorter length Surging breaker: abrupt change in slope, very steep breaker, energy dissipated over shortest length

Describe the origin of these depositional features: spit, bay barrier, tombolo, and barrier island.

Spit: a linear ridge of sediment that extends in the direction of longshore drift from land into the deeper water near the mouth of a bay. Bay Barrier: When the spit closes up the mouth of the bay because the currents weren't strong enough, cutting off the bay from the open ocean. Tombolo: A sand ridge that connects an island or sea stack to the mainland. They can also connect two adjacent islands. Formed in the wave-energy shadow of an island. Barrier Island: Extremely long offshore deposits of sand lying parallel to the coast. Most formed due to sea level rise of glacial melt.

Compare and contrast the circulation between the Red Sea and the Indian Ocean to that between the Mediterranean Sea and the Atlantic Ocean.

Surface water from the Indian Ocean flows through the Gulf of Aden into the Red Sea. AS it flows North, its density increases as evaporation increases its salinity. The dense water sinks and returns as subsurface flow to the sill and the Gulf of Eden. This warm saline water sinks fast until it hit equilibrium level and then flows to the Indian Ocean. Atlantic water enters the Med as surface flow through the strait of Gibraltar to replace rapidly evaporating water. Water level in the Med is 15 cm lower that the Strait of Gibraltar. Surface water also goes North. The rest of the Atlantic water sinks during winter and forms the Mediterranean Intermediate Water. It flows westward at a depth of 200-600 meters and returns to the North Atlantic as a subsurface flow through the Strait of Gibraltar.

Explain why the following statements for deep-water waves are either true or false:

Swell is made up of low frequency, long-crested waves that are uniform in wave characteristics and symmetrical in shape. Swell is not made up of particular wave sizes.

List the two basic processes by which coasts advance seaward, and list their counterparts that lead to coastal retreat.

Tectonic and isotonic processes. Eustatic (change in seawater volume)

Compare the cause and effect of tectonic versus eustatic changes in sea level.

Tectonic- most dramatic, effects elevation of land, emerging shoreline b/c of tectonic plate activity, local sea level falls (ISOSTATIC) Eustatic- global changes in sea level, changes in seafloor spreading rate, ice volumes change, thermal expansion due to warming climate

Observing the flow of the Atlantic Ocean currents in Figure 14, offer an explanation as to why the Brazil Current has a much lower velocity and volume transport than the Gulf Stream.

The Brazil Current is slower and transports less volume than the Gulf Stream because the Brazil Current is impeded by the Falkland Current. The Labrador Current that meets the Gulf Stream is much smaller than the Falkland Current. ALSO, the Brazil current is created by a split in the South Equatorial Current (half of the SE moves south to form the Brazil, the other half moves north and forms the Caribbean current.) The Gulf Stream is not the result of a split.

Which is more technically correct: The tide comes in and goes out; or The Earth rotates into and out of the tidal bulges? Why?

The Earth rotates into the tides, because the tides are in fixed positions relative to the moon and sun, but the Earth is what is moving.

What is declination? Discuss the degree of declination of the Moon and Sun relative to Earth's Equator. WHat are the effects of declination of the Moon and Sun on the tides?

The angular distance of the sun or moon above or below Earth's equatorial plane. The sun's maximum is 23.5 degrees while the moons is 28.5 degrees. The result is that tides are rarely aligned with the equator.

What causes the apex of the geostrophic "hills" to be offset to the west of the center of the ocean gyre system?

The apex of these geostrophic "hills" of surface seawater is displaced toward the western sides of ocean basins because of the Coriolis effect and the relative intensity of the effect with changes in latitude (the Coriolis effect is stronger closer to the poles).

Describe the response of a barrier island to a rise in sea level, Why do some barrier islands develop peat deposits running through them from the ocean beach to the salt marsh?

The barrier reef moves inland due to the rising sea level. The entire island rolls over itself. The peat deposits are formed by the build of of the organic matter in the marsh.

Of flood current, ebb current, high slack water, and low slack water, when is the best time to enter a bay by boat? When is the best time to navigate in a shallow rocky harbor? Explain.

The best time to enter is during the flood current because water is entering the bay at that time, the best time to navigate is during the high slack tide because the water is at the highest point at this time.

Describe the relationship between atmospheric pressure, winds, and surface currents during the monsoons of the Indian Ocean.

The monsoons are caused by the difference in heat capacities of land and ocean. In the summer in the Indian Ocean, the Asian continent warms more quickly than the ocean. In essence, monsoons are just massive sea breezes. Lower atmospheric pressure over land means that winds blow onshore (southwest monsoon). The North Equatorial Current is replaced by the Southwest Monsoon Current (flowing from west to east across North Indian Ocean). During winter, the Asian continent cools more quickly than the ocean. Higher atmospheric pressure over land means that winds blow offshore (northeast monsoon). The North Equatorial Current flows from east to west.

Explain why Red Sea water that flows into the Indian Ocean at a depth of 125 meters (410 feet) sinks to 1000 meters (3300 feet) before spreading throughout the Arabian Sea.

The water is evaporating rapidly and gets very dense and heavy as it becomes more saline. Then it sinks and mixes in at the equilibrium level.

Assuming that there are two moons in orbit around Earth that are on the same orbital plane but always on opposite side of Earth and that each moon is the same size and mass of our Moon. How would this affect the tidal range during spring and neap tide conditions?

They would counteract each other's forces during the neap tide and make each other's stronger during spring tides.

Discuss the origin of thermohaline vertical circulation. Why do deep currents form only in high-latitude regions?

Thermohaline circulation describes the sinking of dense water masses. Density of seawater is controlled by temperature, salinity, and pressure. Because deep-ocean water masses form at the surface of the ocean, we can discount pressure. Temperature controls density more significantly than does salinity. Densest water masses, then, are cold. Deep-ocean currents form in high latitude regions because deep ocean water masses must be cold.

Compare the Atlantic Coast, Gulf Coast, and Pacific Coast by describing the conditions and features of emergence-submergence and erosion-deposition that are characteristic of each.

They are all eroding, with the gulf being the fastest because of coastal development, atlantic followed behind, and the pacific eroding very slowly.

Are tides considered deep-water wave anywhere in the ocean? Why or why not?

They are considered shallow water waves because of their extremely long wavelengths.

Describe the formation of rip currents. What is the best strategy to ensure that you won't drown if you are caught in a rip current?

They are created from the force of the water that is headed back out to sea. You get out by swimming parallel to the shore, then riding a wave into the beach.

What forces produce forced and free standing wave in lake and narrow ocean embayment?

They are wind driven or energy bouncing off the closed end of the bay.

Discuss why some rivers have deltas and others do not. What are factors that determine whether a "bird's- foot" delta (like the Mississippi Delta) or a smoothly curved delta (like the Nile Delta) will form?

They develop deltas because they output more sediment than the longshore currents can get rid of. When depositional processes exceed coastal erosion and transportation processes, a "bird's foot" forms. When it's the other way around you get a smoothly curved delta.

Describe the spawning cycle of grunion, indicating the relationship between tidal between tidal phenomena, where grunion lay their eggs, and the movement of sand on the beach.

They lay their eggs on the highest high tide when sediment has been deposited so that later their eggs will be exposed to the waves.

How is the flow of water in a stream similar to a longshore current? How are the two different?

They move water and sediment from one area to another, but longshore currents move in a zigzag fashion while rivers swirl. Also the direction of the current can change but rivers will always flow in one direction.

Explain what it would look like at the shoreline if the thought of a tsunami arrive there first. What is the impending danger?

This is the "the ocean is disappearing" scenario. If a trough of a tsunami arrives first, seawater will be pulled away from the coastal region. Coastal seafloor will be exposed. Behind the trough follows the crest and an uprush of ocean water. The impending danger of course is death by either drowning or being dashed onto man-made structures inland when the crest of the wave arrives.

Name the two major deep-water masses and give the locations of their formation at the ocean's surface.

Two major deep-water masses are North Atlantic Deep Water (NADW), formed in the North Atlantic by complex mixing of water from the Norwegian Sea, Gulf Stream, and other water masses in the North Atlantic (including Mediterranean Intermediate Water), and Antarctic Bottom Water (AABW) formed by sinking of very cold, dense surface seawater around Antarctica.

Describe the difference between vertically mixed and salt wedge estuaries in terms of salinity distribution, depth, and volume of river flow. Which displays the more classical estuarine circulation pattern?

Vertically Mixed (Most classical estuarine circulation pattern), Uniform salinity: Surface to bottom up from head to mouth, shallow, low volume Salt Wedge, Strong halocline (vertical) at any point, Deep, High volume - EX: Columbia River Estuary

Discuss the formation of such erosional features as wave-cut cliffs, sea caves, sea arches, sea stacks, and marine terraces.

Wave-cut Cliffs: Waves pound at the bottom portion of clif, wakening the top and making them crumble. Sea Caves: Areas where the top has not crumbled down. Sea Arches: Caves that have eroded all of the way through Sea Stacks: Sea arches where the top has crumbled away Marine Terraces: Uplifting of the wave-cut bench.

How does coastal runoff of low-salinity water produce a coastal geostrophic current?

Wind & runoff create Coastal Geostrophic Currents. Piled up surface water affected by Coriolis Effect & friction. Flow parallel to the coast.

If Earth did not have the Moon orbiting it, would there still be tides? Why or why no?

Yes there would still be tides but not as strong, because the sun still has an effect on the tides.

Describe the different ways in which currents are measured.

direct: either a floating device or a stationary device that tracks density, speed, etc indirect: 1. determine density and pressure gradient across area 2. radar altimeters (satellite) 3. low freq sound, determines diff in pressure

List the types of hard stabilization and describe what each is intended to do.

groin- trap sand moving along coast in longshore transport jetty- protect harbor entrances from waves and trap sand migrated eastward across coast breakwater- break waves and create a harbor, accumulates sand, parallel to beach seawall- armor the coastline

Compare the forces that are directly responsible for creating horizontal and deep vertical circulation in the oceans. What is the ultimate source of energy that drives both circulation systems?

horizontal waves directly driven by wind vertical circulation driven by changes in water density (starts in polar ice caps) the SUN ultimately drive both systems

What is longshore drift, and how does is it related to a longshore current?

longshore drift is movement of sediment in a zigzag fashion. It is caused by the longshore current. Longshore current is what is moving the water and sediment.

Describe the physical changes that occur to a wave's wave sppes (s), wavelength (L), height (H), and wave steepness (H/L) as a wave moves across shoaling water to break on the shore.

wave speed decreases (they slow down as they reach shore λ decreases (crest to crest distance shortens as waves reach shore and are "pressed" together) wave height increases (waves get taller as they reach shore) wave steepness increases (waves get taller but distance between them (λ) gets shorter = steeper waves)