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121 terms

Oceanography

Chapters 9-14
STUDY
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Surface currents are primarily driven by:
Wind
About 10% of the water in the world ocean is involved in:
Surface Currents
t/f Because of the coriolis effect, surface currents in the Northern Hemisphere flow to the left of the wind direction
False (Right)
Continents and basin topography often block continuous flow and help deflect the moving water in a circular pattern. The flow around the periphery of an ocean basin is called:
A gyre
t/f In Ekman transport, the direction of the flow of water is 90 degrees to the right of the wind direction (in the northern hemisphere).
True
Which of the following is NOT a geostrophic gyre?
Antarctic Circumpolar Current (or Westwind Drift)
Water flows in how many great surface circuits?
6
A boundary current that is narrow, fast, and deep is typically called
Western Boundary Current
A wide, shallow, slow current is typical of:
Eastern Boundary Current
The Canary current in the North Atlantic is shallow, and broad and cold. What type of current is it?
Eastern Boundary Current
t/f Surface currents distribute tropical heat worldwide and influence weather and climate.
True
The Scilly Isles off the west coast of England have tropical plants as a result of...
The warm Gulf Stream that brings tropical warmth up from the equator in the Atlantic
Wind induced upward movement of water that brings deep, cold, nutrient rich water toward the surface is called:
Upwelling
Downwelling helps the deeper ocean with..
supply of dissolved gases and nutrients
assists in the distribution of living organisms
t/f Winds that blow steadily across the ocean that induces long sets of counter-rotating vortices (or cells) at the surface water is called Southern Oscillation.
False (Langimuir Circulation)
During major ENSO (El Nino Southern Oscillation) events, sea level in the eastern Pacific.
Rises by as much as 20 centimeters
Because density is a function of water's temperature and salinity, the movement of water due to differences in density is called:
Thermohaline circulation
t/f The global pattern of deep circulation resembles a vast "conveyor belt" that carries surface water to the depths and back again
True
A wavelength is determined by the
horizontal distance between two wave crests
The time it takes for a wave to move a distance of one wavelength is known as
Wave period.
The wave you surf on in California may have come from the middle of the Pacific. What has been transmitted across the ocean basin?
energy
t/f The vertical distance between a wave crest and the adjacent trough is the wavelength.
False (Wave height)
t/f A Wave that is moving through water deeper than one-half of the wavelength are known as deep water waves.
True
t/f The slowing and bending of waves as they approach the shore from an angle is called wave reflection.
False (Wave REFRACTION)
A wave that cannot "feel" the bottom is a ________________
Deep Water Wave
The two types of waves that are always or almost always deep water waves are ____________ and _____________.
capillary waves; wind waves.
The factors necessary to make a really large wind wave are _____________, ___________, and ___________.
wind strength, wind duration, and fetch
The abrupt bulge of water driven ashore by a tropical cyclone (hurricane) is called a ___________.
storm surge.
Which of these lists is arranged in order from smallest wavelength to longest wavelength?
capillary wave, wind wave, tsunami, tides
Wind waves are examples of orbital waves in which:
Particles of water move in closed circles
t/f Progressive waves and orbital waves involved movement of water particles until a depth of one quarter the wavelength.
False
A wind wave of 20-meter wavelength will act as a _____ if it is passing through water MORE than 10 meters deep.
Deep-water wave
A strong wind that blows continuously in one direction for almost three days will create the maximum wave size theoretically possible for a wind of specific strength, duration, and fetch.
Fully developed sea
_____ waves occur in the ocean at the base of the pycnocline, especially at the bottom edge of a steep thermocline.
Internal
A tsunami can be caused by:
Asteroid impacts
Landslides
Volcanic eruption
t/f Often a dangerous consequence of Tsunamis is that the trough of the wave occurs first and subsequently attracts people to explore further offshore.
True
Modern tsunami warning systems depend on:
Submerged devices
Satellites
Seabed Seismometers
What, in December of 2004, was one of the worlds worst natural disasters on record, killing nearly 300,000 people in all.
The Sumatran Tsunami
The moon has a greater effect on the Earth's tides than the sun because
it is much closer to the Earth than is the sun
The two largest tide-generating forces on earth are
gravitational pull of the moon and sun
Spring tides occur when
the Earth, Moon and Sun are all in alignment
Neap tides
occur one week after spring tides
The central point, or node, for a tide in an ocean basin where little change in vertical height is masured is known as the:
Amphidromic point
A tide with two unequal high water marks each tidal cycle is called
mixed semidiurnal tide
In a region with semidiurnal tides, if a high tide occurs at midnight (12 AM), the next low tide will occur at
6:12 AM
In a region with diurnal tides, if a high tide occurs at midnight (12 AM), the next high tide will occur at __________________.
12:50 AM the following day
A wave of water moving up a river, initiated by tidal action and normal resonances within a river estuary, is called ________________.
A tidal bore
t/f The tidal cycle is 24 hrs 50 minutes long because the moon rises 50 minutes later each day.
True
t/f True amphidromic systems do not develop in narrow basins because there is no space for rotation.
True
When high or low tidal currents begin to change direction, it is called:
Slack water
What organism uses the tides, specifically high spring tides, to time their breeding behaviors?
Grunion
What is the tidal datum in reference to in regions with mixed tides?
Mean lower low water (MLLW)
What is the relationship between the heights of tides and the amphidromic point?
Heights increase with distance from the amphidromic point
What type of current occurs during a high tide?
Flood current
What is an ebb current?
The fall in sea level as a tide trough approaches
The east coast of the United States receives two high tides and two low tides of roughly the same heights per day. What kind of tidal pattern is this?
Semidiurnal tides
t/f Tides can have a wavelength equal to one tenth of the Earth's circumference.
False
t/f High tides are associated with the area between bulges.
False
The transport of sediment along the beach is due to
Longshore currents
Berms, berm crests, and longshore bars are all features of:
Depositional coastlines
A fjord is
a long, narrow, steep-sided, flooded coastal valley
t/f Barrier islands are exposed sandbars parallel to the coast, form when sediments accumulate on submerged rises paralleling the shoreline.
True
A is the area where ocean meets the land and a is the larger zone affected by the processes that occur at that boundary.
shore; coast
t/f A coral reef coast is a product of living organisms.
True
What is usually the highest point on a beach?
Berm crest
What is a coastal cell?
A section of coastline that has a balance of input and output of sand
What is the term for global, long term-change to sea level?
Eustatic change
Which of the following are NOT factors of Eustatic change?
Movement of the longshore current
What type of coastline has sea caves, blowholes, sea arches and sea stacks?
An erosional beach
What is the name for a relatively old coast that are steadily growing due to their sediment accumulation?
Depositional coasts
How much of the United States coastline is considered to be depositional?
30%
What type of reef is a ring-shaped island of coral with a lagoon at its center?
Atoll
t/f Seawalls increase the amount of erosion along the shore because they deflect wave energy.
True
t/f Global glaciation events does not create variations in local sea level changes.
False
During the sand on a depositional beach accumulates and during the the sand erodes from the beach and is moved to an offshore location.
summer; winter
Chesapeake Bay is an example of:
A drowned river valley
What is a factor that is instrumental in shaping an erosional coast?
Wind-driven grit abrasion
Stream erosion
Dissolution of acids and bases
High energy coasts tend to be
Erosional
Selectively straightened
What layer of the ocean is permanently devoid of light?
Aphotic zone
What is the largest biogeochemical cycle?
Global Carbon cycle
What is a more accurate term for the feeding relationship of organisms involving multiple organisms at each trophic level for a higher level organism to eat?
Food web
What is a heterotroph?
An organism that eat other organism
t/f Before nitrogen can be used by organisms to make proteins and nucleic acids, it must first be fixed into a usable form such as nitrates.
True
A salmon migrates from the ocean to freshwater rivers to spawn. Which of the following best describes what type of environment the salmon moves from and into?
Hypertonic to Hypotonic
What open water zone is near shore and over the continental shelf?
Neritic zone
Movement of a substance along a concentration gradient where substances move from higher concentration to lower concentration is called:
Diffusion
Diffusion of water across a semipermeable membrane is called:
Osmosis
What is needed for living matter to function?
Energy
Chemosynthesis is the main method of binding energy into carbohydrates on the planet.
False
t/f Hydrothermal vent communities depend on chemosynthesis in order to capture energy and convert inorganic molecules into glucose molecules.
True
t/f Most biological productivity in the ocean occurs in the aphotic zone.
False
t/f On average, the ocean has a higher primary productivity at 150 gC/m2/year than land at 120gC/m2/yr.
False
Which of the following is NOT one of the four factors that influence primary production?
Heterotrophs
Which of the four factors that influence primary production are limiting in the oceanic environment?
Inorganic Nutrients
Sunlight
A trophic pyramid describes who eats whom, and in general, from one level to the next, what percentage is transferred?
10%
Which of the following elements are found in all organic molecules?
Carbon
t/f Primary production varies with latitude and with season.
True
What is plankton?
A drifting organism
What connects all plankton?
Ecological lifestyle
Why are phytoplankton critical for marine life?
They are large contribution to marine food webs
They generate massive amounts of atmospheric oxygen
They are able to bind billions of tons of carbon into carbohydrates
Which plankton are considered microplankton?
Dinoflagellates
What is the smallest form of plankton and includes most viruses?
Femtoplankton
What planktonic group accounts for 80% of all photosynthesis in the tropics?
Picoplankton
What is a frustule?
The rigid cell wall of a diatom
What allows diatoms to expand in size during reproduction?
Auxospore
What is usually the culprit for a harmful algal bloom known as red tides?
Dinoflagellates
A highly biological productive ocean surface appears chalky due to the calcium carbonate cell walls. This is due to the successful bloom of what plankton ?
Coccolithophores
What is essential in the restoration of nonconservative nutrients and supports the continuation of photosynthetic productivity in the ocean?
Upwelling
What factor(s) limit primary productivity in the ocean?
Angle of the sun
Turbidity
Surface turbulence
What is true of compensation depth?
It is the depth at which carbohydrate and oxygen production equals the amount of consumption
It marks the bottom of the euphotic zone
What kind of plankton remains planktonic for its entire life?
Holoplankton
What kind of plankton remains planktonic for only part of its life?
Meroplankton
t/f There are plankton in every major group of animals.
True
t/f Approximately 55% of the sunlight energy absorbed by diatoms is converted into energy for carbohydrate chemical bonds.
True
t/f Coccolithophores are able to utilize more frequencies of light so they can be deeper in the euphotic zone and need less light.
False
t/f Nearshore productivity is almost always more productive than open ocean productivity.
True
t/f Seaweeds are not a type of plant.
True
t/f Seaweeds or multicellular algae have vascular tissues
False
Seaweeds do NOT have:
leaves
Low, muddy coasts in tropical and some subtropical areas are often home to tangled masses of:
trees called mangroves
Seaweeds are classified by:
their photosynthetic pigments