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Marine Science Exam 3
Ch. 12-15
94
Science
Undergraduate 1
11/16/2011

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Term
What is Equilibrium Tide Theory?
Definition
The total gravitational force between the moon and the Earth causes bulges. The surface nearest the moon there is a tidal pull and where the Earth is farthest from the moon.
Term
What is a semi-diurnal tide?
Definition
A tide that has two high and two low tides each tidal day. The two high tides and the two low tides each are equal heights.
Term
What is a diurnal tide?
Definition
Diurnal tides have one high tide and one low tide. These tides are equal in height.
Term
What is a mixed tide?
Definition
Mixed tides have two high and two low tides each day but they are not equal.
Term
How many times does tidal range reach a maximum during one lunar month?
Definition
Twice.
Term
How long is one lunar month?
Definition
29.5 days.
Term
Tides with the largest tidal range during the month are ___?
Definition
Spring tides.
Term
Tides with the smallest tidal range during the month are ___?
Definition
Neap tides.
Term
How many sets of each (Spring and Neap) tide are there each month?
Definition
Two sets.
Term
What phase is the moon in during Spring tides?
Definition
Full and new.
Term
What phase is the moon in during Neap tides?
Definition
First and third quarter.
Term
What is the dynamic theory?
Definition
That the tide is a shallow water wave that travels around an ocean basin.
Term
What is the average speed of a tide according to the dynamic theory?
Definition
700 km/hr
Term
What is a amphidromic system?
Definition
High and low tide points (crests and troughs) move around the basin in a rotary path.
Term
What direction does water move in the Northern hemisphere?
Definition
Counter-clockwise.
Term
What direction does water move in the Southern hemisphere?
Definition
Clockwise.
Term
What is a co-tidal line?
Definition
Co-tidal lines connect all points experiencing the same phase of a tide. Co-tidal lines will not be evenly spaced or consistently shaped.
Term
What is a co-range line?
Definition
Co-range lines connect all points with equal tidal range. They form irregular circles.
Term
What is a tidal bore?
Definition
A tidal bore is a tidal phenomenon in which the leading edge of the incoming tide forms a wave of water that travel up a river or narrow bay against the direction of the river or by's current.
Term
Where do bores occur?
Definition
In areas with a large tidal range.
Term
When do tidal bores take place?
Definition
During the flood tide.
Term
What are two key features of tidal bores?
Definition
Intense turbulence and turbulent mixing.
Term
What is a beach?
Definition
Wave-worked sediment that moves along the wave-cut bench (everything).
Term
What is a berm?
Definition
Dry, sloping region at foot of cliffs or dunes, horizontal portion of the beach back shore.
Term
What is a beach face/ low tide terrace?
Definition
Wet surface sloping from berm to shoreline.
Term
What is a longshore bar?
Definition
Longshore bars come and go seasonally. They are mounds of sand that extend parallel to shoreline and cause waves to break.
Term
What is a foreshore?
Definition
The foreshore is the second zone of the beach, between the highest point reaches by the waves at high tide and the lowest point exposed at low tide.
Term
Wat is a longshore trough?
Definition
Lies between longshore bar and beach, it is the part of an ocean wave that is displaced below the still-water line.
Term
What is a summer beach profile?
Definition
Long, low, gentle waves. Steep profile, fair weather with sand being pushed up towards the coast. Berm is much wider, deeper, finer sand on shore.
Term
What is a winter beach profile?
Definition
Short, high waves and stormy weather. Sand is being forces out into the ocean creating a sand bar and a shorter berm. Foreshore is gently sloped and backshore is steep. Waves reach further.
Term
Longshore bars more typically appear in what season?
Definition
Winter
Term
How do pebble and cobble beaches differ from fine-grained sand beaches?
Definition
Pebble and cobble have 10-20 degree slopes because water can move easily through large grains. More particles are carried seaward. Fine grained sand has a small slope because water cannot trickle down.
Term
When is wave energy heavier?
Definition
In the fine-grained sand of the summer.
Term
What are features of an erosional coast?
Definition
Erosion on the shore due to wave action, rivers, and glaciers. Sea cliffs and rocky shores.
Term
What are features of a depositional coast?
Definition
Features created by deposition of sediments. Sediments accumulate from a local source and are transported. Deltas, mangrove swamps, salt marshes, barrier islands, and beach-sand dunes.
Term
What type of coast is undergoing tectonic uplift?
Definition
Erosional coast
Term
What type of coast is undergoing subsiding (sinking)?
Definition
Depositional coast
Term
How is a marine terrace formed?
Definition
Cycles of uplift/erosion and sea level changes. A region rises above sea level, waves erode it, another uplift raises the region again, waves erode new areas, etc.
Term
What type of coast are spits and bay-mouth bars associated with?
Definition
Depositional coasts.
Term
What prcess allows spits and bay-mouth bars to grow?
Definition
They are formed on coastlines where large amounts of sediments come with longshore drift. Spits are narrow strips of land, bay-mouth bars form when spits grow completely across the mouths of bays.
Term
What causes barrier islands to migrate?
Definition
Rising sea level
Term
How is sand carried to the lagoonal (back) side of a barrier island?
Definition
Sea level rises, sand is washed over the island and onto the other side, island is eroded on seaward side, and grow on shoreward side.
Term
Which coast (Atlantic or Pacific) is rising?
Definition
Atlantic
Term
Which coast (Atlantic or Pacific) is eroding?
Definition
Pacific
Term
What are the two causes of post-glacial sea level rise?
Definition
Melting of glaciers and warming/expanding of ocean water.
Term
How does sea level rise occur?
Definition
When coasts are drowned and new coastlines form inland from their previous location.
Term
What is a delta?
Definition
Emergent accumulation of sediment deposited at the mouth of a river as it flows into a standing body of water.
Term
What are the depositional features of deltas?
Definition
Large loads of sediment, shallow sea at river mouth, sheltered coast with weak tides and currents, absence of large lakes along the course of the river which could siphon out sediment.
Term
What processes are different in a bird-foot delta (Mississippi) and a traditional fan-shaped delta (Nile)?
Definition
Birds-foot deltas do not avulse often enough to form a symmetrical fan shape. (Avulse meaning to redistribute sediment).
Term
What is an emerging shoreline?
Definition
A coastal area that has been exposed due to a relative fall in sea level.
Term
What is a submerging shoreline?
Definition
A coastal area that has been covered by water as a result of rising sea level.
Term
Why do shorelines become emerged/submerged?
Definition
Because of isostatic or eustatic changes.
Term
What is isostatic change?
Definition
Continent edge rises or sinks
Term
What is eustatic change?
Definition
Volume of water in the oceans changes
Term
Is sea level rising where there is isostatic change or where there is eustatic change?
Definition
Isostatic change
Term
What methods are being used to prevent erosion?
Definition
Breakwaters, jetties, seawalls, and beach nourishment.
Term
What are breakwaters?
Definition
Artificial structures built in the ocean to protect coastal areas from the wave damage. They are constructed offshore to absorb some of the energy of harmful waves.
Term
What are jetties?
Definition
Structures built on either side of an inlet between two barrier islands to maintain navigation channels by preventing silting and erosion. They cause sand to accumulate on the up-current side and to erode on the down current side.
Term
What are seawalls?
Definition
Structures made to protect beachfront property from wave damage as well as to restore the beach sand by interfering with longshore drift.
Term
What is a groin?
Definition
Structure similar to a seawall, intended to stop beach erosion.
Term
What is beach nourishment?
Definition
Beach replenishment by replacing sand lost to longshore drift with new sand from an outside source. Meant to protect from wave damage and reverse effects of erosion.
Term
What is photosynthesis (in words)?
Definition
When energy in the form of sunlight is added to Carbon Dioxide, nitrogen and phosphorus (nutrients), and water resulting in organic matter in the form of glucose and oxygen.
Term
What is respiration?
Definition
Respiration is the transport of oxygen from the outside air to the cells within tissues and the transport of carbon dioxide in the opposite direction.
Term
What is the difference between gross primary productivity and net primary productivity?
Definition
Net primary production is the rate at which all plants in an ecosystem produce net useful chemical energy while gross primary production is the rate at which the plants in an ecosystem produce useful chemical energy.
Term
GPP - respiration =
Definition
NPP
Term
What factors control primary productivity?
Definition
In the tropics, lack of nutrients limits PP. In the poles, lac of sunlight limits PP.
Term
What is the euphotic zone?
Definition
This zone is well lit by sunlight and sufficient for photosynthesis. (20m-100m).
Term
What controls depth in the euphotic zone?
Definition
Water clarity controls how deep light distribution is.
Term
How does the euphotic zone differ in coastal areas vs. the open ocean?
Definition
In open coeans, light reaches about 200 m deep and only about 50 m deep in coastal waters. Coastal waters are not as deep as the open ocean.
Term
What is the role of upwelling in primary productivity?
Definition
Upwelling brings nutrient-rich water up to the surface of the water, which increases primary productivity.
Term
What is the difference between eutrophic vs oligotrophic conditions?
Definition
Oligotrophic conditions include deficient plant nutrients, low PP, small amounts of organic matter, clear water, and deep water. Eutrophic conditions are efficient plant nutrients, high PP, high amounts of organic matter, less clear water, and shallower water.
Term
What are red tides?
Definition
Red tide is caused by algal blooms during which algae become so numerous that they discolor coastal waters, deplete oxygen, and release toxins.
Term
What type of marine organisms carry out photosynthesis?
Definition
Plants, phytoplankton, and cyanobacteria.
Term
What are diatoms?
Definition
Unicellular algae with external skeletons. They vary in size. They form large blooms and form chains.
Term
What are coccoliths?
Definition
They are microscopic planktonic algae with calcareous disks called coccoliths. They form large blooms.
Term
What are dinoflagellates?
Definition
Single celled microscopic organisms considered Protista. Can form blooms known as red tides.
Term
What is the carbon cycle?
Definition
Circulation of carbon from the ocean surface to sea floor.
Term
How does the biological pump work?
Definition
Circulates carbon by taking atmosphere Carbon Dioxide, dissolving it, phytoplankton turning it into dissolved organic matter, matter sinks.
Term
What is the biological pump?
Definition
It transfers carbon from the surface of the ocean to it's depths through processes such as downwelling.
Term
What factors control primary productivity between the poles, equator and mid-latitudes?
Definition
PP varies with latitude. Tropics are not limited by sunlight, poles are isothermal and less likely to be limited by nutrients. Mid-latitudes are limited in getting nutrients because of thermocline.
Term
What is the red field ratio?
Definition
The ratio of carbon to nitrogen to phosphorous that is necessary to sustain photosynthesis.
Term
Wat dies a red field ratio represent?
Definition
It is the stoichiometry of photosynthesis. Inorganic carbon, nutrients, water, and sunlight.
Term
What is the main reason that Nitrogen is the limiting nutrient for photosynthesis?
Definition
Nitrogen atoms are a part of all protein molecules and the molecules of chlorophyll. It is the limiting nutrient because decomposition of particulate organic matter to ammonium is a much slower process than the release of phosphorus.
Term
What is meant by trophic levels and transfer efficiency?
Definition
A trophic level is defined as each step in the food chain. Transfer of energy is inefficient because only 10% transfers from level to level.
Term
What is the difference between food chains and food webs?
Definition
A food chain is a single line of organisms where each is preceded by something that consumes and is followed by something that consumes it. A food web branches out in all directions with arrows pointing from organisms to any number of consumers.
Term
What is the variation of salinity and temperature in the coastal oceans, tropics, mid-latitudes, and poles?
Definition
Salinity is higher in mid-latitudes because evaporation exceeds precipitation. Salinity is higher in restricted areas of the oceans like the Mediterranean and Red Seas. Salinity is lower near the equator because precipitation is higher. Salinity is low near the mouths of major rivers because of fresh water input. Temperature of surface water varies with latitude. Density and salinity increase with depth. Temperature decreases with depth.
Term
Where does cooler water come from and where is it heated?
Definition
Cool water circulates towards the equator where it s warmed adnt hem circulates back to the poles.
Term
What is an estuary?
Definition
An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it.
Term
What is a bar-built estuary?
Definition
Bar built estuaries are formed when sandbars build up along the coastline. These sand bars cut off the waters behind them from the sea. They are usually shallow. Wind-driven.
Term
What is a tectonic estuary?
Definition
Where there are large cracks and faults in the earth, land sinks and tectonic estuaries are created when the sea fills in the area. (San Francisco Bay)
Term
What is a fjord?
Definition
A long narrow inlet with steep sides or cliffs, crated in a valley carved by glacial activity. Formed when a glacier cuts a U-shaped valley.
Term
What is vertically homogenous tidal mixing?
Definition
When forces exceed river output, resulting in a well mixed water column and the disappearance of the vertical salinity gradient. (Delaware Bay, Raritan River, New Jersey)
Term
What is partially mixed?
Definition
River output becomes less than the marine input. Current-induced turbulence causes mixing of the whole water column such that salinity varies more longitudinally rather than vertically.
Term
What is inverse-inverse mixing?
Definition
Occur in dry climates where evaporation greatly exceeds the inflow of fresh fresh water. A salinity max zone is formed and both river and ocean water flow close to the surface in this zone. Water is pushed down and spread along the bottom. (Spencer Gulf)
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