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Oceanography
Final
72
Geology
Undergraduate 2
04/14/2008

Additional Geology Flashcards

 


 

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Term
Shore
Definition
Zone that lies between the lowest tide level and highest elevation on land that is affected by storm waves (a few m to 100m)
Term
Coast
Definition
extends inland from the shore as far as ocean-related features can be found (a few m to 100m)
Term
Coastline
Definition
Marks the boundary between the shore and the coast
Term
Beach
Definition
Entire active area affected by waves that extends from low tide breaker line to the base of the coastline
Term
In a classical beach profile be able to identify a berm, beach face, longshore bar, shoreline, backshore, foreshore, nearshore, offshore
Definition
[image]
Term
and define a berm, beach face, longshore bar, shoreline, backshore, foreshore, nearshore, offshore
Definition
Berm- dry, gently sloping region at the foot of coastal cliffs or dunes (parallel to the shore)
Beach Face- wet, sloping surface that extends from the berm to the shoreline (low-tide)
Longshore bar- offshore sand bars that parallel the coast
Shoreline- waters edge
Backshore-Above teh high tide shoreline
Foreshore-portion exposed at low tide and submerged at high tide
Nearshore- extends from the low tide shoreline to the low tide breaker zone
Offshore- portion behind the low tide breakers
Term
Why do beaches have different composition?
Definition
Whatever is available to be brought there.
Quartz is most resistant for new jersy
Shells in hawaii come from coral reefs.
Olvine is made from basalt
Term
What causes the perpendicular movement of sand on the beach? How is it different during light and heavy wave activity (think of swash and backwash)?
Definition
Caused by breaking waves
-Light wave activity moves and up the beach face toward the berm (swash dominates) - summer
-Heavy wave activity moves sand down teh beach face to the longshore bars (backwash dominates)-winter
-Produces season changes in the beach
Term
Draw a summer and a winter beach profile labeling all the important features (berm, beach face, and longshore bars).
Definition
[image][image]
Term
What are longshore currents? How are they established?
Definition
Longshore Currents- are local currents that parallel the shoreline, largely generated by waves that strike the shore at some angle
Term
What is the longshore drift or transport? How is it established? What is the overall direction of the longshore drift along the coasts of the US?
Definition
Longshore drift/transport- is the movement of sediment in a zigzag fashion caused by the longshore current. Overall direction on both coasts of the U.S. is Southward
Term
What are erosional shores? List some of the processes acting on these shores.
Definition
Erosional shores (rocky)- dominated by land and marine processes that remove coastal material
-Land erosion- streams, abrasion of wind driven particles, ice, rain, dissolution, mass movements
Marine erosion- waves, abrasion of wave-driven particles, dissolution, marine organisms
Term
Characteristics of erosional shores
Definition
In general these are areas of high energy, and many of the features we see are formed by waves eroding rocks
-Coves, Sea arch, Sea cliffs, Sea cave, Sea Stack, Headland, Blowhole
Term
What are depositional shores? List some of the processes acting on these shores.
Definition
Depositional shores (sandy): dominated by depositional processes; they are steady or growing
Bay, Lagoon, Inlet, Barrier island, Tombolo
areas tectonically inactive, tend ot subside over time-> East Coast
-Any process that can bring sediment onto a beach
Term
What is the process of shore straightening?
Definition
Term
What is the process of shore straightening?
Definition
When a cliff or a shore is born, not all the portion of these cliffs are made of the same materials
Rigid shore is slowly eroded until bay fills in and cliffs erode away till its flat
Term
What is the hard stabilization of a coastline?
Definition
Structures built to protect coastline may prevent erosion of part of the shoreline but can result in accelerated erosion elsewhere
Hard Stabilization perpendiclur to the coast
-groins-designed to trap sand
-Jetties- protect harbor entrances
Hard stabilization parallel to the coast
-Breakwaters- built beyond the surf zone
-Seawalls-built to armor the coast
Term
Groins-
Definition
Jet out perpendicular to coast, Sand is carried and build up on one end of groin taken from other side causing jagged pattern
Term
Jetties
Definition
Like groins but two block harbor entrance.
Sand build up on one side and eroded down the coast for other, eventually has to be moved from built up side to eroded side or else harbor will fill with sand
Term
Alternatives to Hard Stabilization
Definition
-Restrict the building of structures too close to the shore
-Relocate structures as erosion threatens them
Term
What is artificial beach nourishment?
Definition
It occurs when sand is dredged and pumped onto the beach from offshore
Term
Define ecology, environment, ecosystem, community, habitat.
Definition
Ecology- the study of the inter-relationships between the physical and biological aspects of the environment. It is the study of how organisms adapt to their environment and in turn alter it
Environment- the sum of all the physical, chemical, and biological factors to which an organism or community is subjected
Ecosystem-includes both the living (biotic) and non-living (abiotic) portions of the environment
Community- the populations of all species that occupy a particular habitat and interact within the habitat
Habitat- the place where an individual or population of a given species lives
Term
How are marine provinces divided? How are the benthonic and pelagic environments subdivided?
Definition
Benthonic-Bottom
Pelagic - Water Column
Term
Benthonic environment
Definition
Divided by depth
Intertidal
Littoral- band of coast alternativley covered and uncovred by tidal action
Sublittoral zone- goes to the edge of the continental shelf
Bathyal zones covers seabed on the slopes and down
Abyssal- below the abyssal plain
Hadal- Deep part of the trenches
Term
Pelagic Environment
Definition
Divided broadly into the nertic zone and oceanic zone
Nertic (near the shore over the cont shelf)
Deep-water Oceanic Zone beyond the cont shelf
epipelagic, mesopelagic, bathypelagic,abyssalpelagic, and hadalpelagic zones (know order)
Term
1Which zones can be identified in the ocean based on light penetration? Define these zones.
Definition
Photic Zone- layer of seawater where the light is sufficient for photosynthesis
Euphotic Zone- the upper part of the photic zone where most of the primary productivity occurs
Dyshpotic zone- where illumination is too weak for photosynthesis to generate enough carbohydrates needed by autotrophs for a whole day
Aphotic Zone- receives no light from the surface because it is all absorbed by the water above
Term
How can marine organisms be classified based on life style?
Definition
Plankton Nekton, Benthos
Term
Plankton
Definition
Organisms which float in the water and have no ability to propel themselves against a current (weak swimmers)
Plants- phytoplankton - Algae sargassum?
Animals- zooplankton-jellyfish
Term
Nekton
Definition
active swimmers and include marine fish, reptiles, mammals,birds, etc
Squid, yellowfish tuna, seahorse
Term
Benthos
Definition
organisms that live on the bottom (epifauna) or within the bottom sediments (infauna)
Seagrasses
Term
What are some of the characteristics of the deep sea environment?
Definition
-Deep sea = aphotic zone
-Only very upper mesopelagic area receives somelight
-Photosynthesis impossible
-Organisms have to rely on senses other than vision to find food or mates
-High hydrostatic pressure
-Almost constant condition (S & T, no seasons)
-Oxygen is always present in concentrations sufficient to support life
-Paucity of food (no photosynthesis, food must fall from the surface)
Term
How do deep sea fish adapt to the light conditions that characterize their environment?
Definition
Color themselves so that they are nearly invisble
Mesopelagic fish- have larger eye size relative to epipelagic species (to try to see)
Abyssalpelagic fish have small or reduced eyes (don't bother)
-Big mouths and long teeth able to swallow prey larger than themselves (hang on to it for a while)
-Attract prey or mates with light (mostly mesopelagic because they have eyes) HOLD ON TO YOUR MAN
Term
What is the suspended matter in seawater? Does it contribute to salinity?
Definition
Floating clay, silt, and some organic material. No it doesn't contribute to salinity.
Term
What is the dissolved matter in seawater? Does it contribute to salinity?
Definition
a. major constituents (salts)- mostly present in their ionic forms as anions and cations
b. Dissolved gases- O2, N2, CO2
c. Nutrients- the elements N, P, and Si,essential for organism
d. trace elements
Outside of gasses they all contribute to salinity
Term
What is salinity? What are the units used to express salinity? What is the average salinity of seawater?
Definition
"the total amount of solid material dissolved in one kilogram of sea water, when all the carbonate has been converted to oxide, all bromine and iodine replaced by chlorine, and all organic matter completely oxidized"
3.47g/kg or 34.7 parts per thousands
Term
List the major dissolved ions in seawater.
Definition
1. Chloride (Cl-)
2. Sodium (Na+)
3. Sulfate (SO..
4. Magnesium (Mg
5. Calcium (Ca
6. Potassium (K+)
7. Bicarbonate (HCO...
Term
Explain the origin of the ocean salinity.
Definition
-Salts come from crustal rocks through chemical dissolution of minerals by water (rivers, rain, groundwater, waves)
-> salts in the ocean though are different from the ones present in concentrated river water
- Excess volatiles come from outgassing of volcanoes and hydrothermal vents
Term
Explain the Principle of Constant Proportion.
Definition
A principle that states that the major constituents of ocean-water salinity are found in the same relative proportion throughout the ocean-water volume, independent of salinity
With one of the seven ions concentration you can figure out the rest, can calculate salinity from chlorinity
Term
What does it mean that the oceans are in a ‘steady state’?
Definition
-Evidence that sea-salt compositions and probably seawater salinity have not varied much over the past billion years
-steady state for major and minor dissolved constituents of seawater
-the rate at which an element is added to the ocean equals the rate at which it is removed
Term
What are some of the sources and sinks of ocean’s salinity?
Definition
SOURCES- rivers, volcanic eruptions, hydrothermal activity
SINKS- salt sprays, biological processes, precipitation of authigenic minerals, adsorption to the surface of sinking clays, hydrothermal activity
Term
What is the residence time of an element in the oceans? What are the basic assumptions that oceanographers make when calculating the residence time of an element?
Definition
Residence Time = Amount of element in ocean/Rate at which the elements is added or removed from the ocean

Residence time is the average time that an atom of an element spends in the ocean.
Assumes- the existence of steady-state conditions and a well-mixed ocean
Term
If the total mass of water in the oceans is 1.35x1024 g, the concentration of the element X is 6.7 ‰, and its input rate is 6x1012 g/yrs, what is the residence time of X?
Definition
use a calculator check later
Term
What is meant by conservative and non-conservative elements? Can you give a few examples?
Definition
Conservative constituents- they occur in constant proportion or change very slowly through time. They have long residence time
Non-conservative constituents- they are tied to biological or seasonal cycles or to very short geological cycles. They have short residence time.
Term
What are the major gases dissolved in seawater?
Definition
Nitrogen, Oxygen, and Carbon dioxide
99% of the gases in the atmosphere in the oceans
-In equilibrium with atmosphere (not equal)
Term
Explain how gases are dissolved in the ocean. What controls their concentrations at the surface? Is it different a depth? Why? What are the units used to express their concentration in seawater?
Definition
-Gases move between the ocean and the atmosphere at the air-water interface. Atmospheric gases dissolve in the seawater and are distributed to all depths by mixing processes and currents
-Deeper in the oceans some of them will have been depleted and the amount and composition of gases in ocean water will vary.
-Dissolved gases are usually measured in terms of milliliters of gas dissolved in one liter of water ml/l, sometimes ppm
Term
Compare the concentration of the major gases in seawater and in the atmosphere.
Definition
Nitrogen Atmosphere-78.08% Seawater-48%
Oxygen Atmosp 20.95% Seawater- 36%
Carbon dioxide Atmo .035% Seawater- 15%
Term
What are the factors that control the total amount of a gas that can be dissolved in seawater?
Definition
The total amount of gas that can be dissolved is proportional to the atmospheric concentration of the gas and its solubility
-At the surface the amount of mixing of atmospheric gas into water is proportional to wind velocity
Term
What factors control the solubility of a gas?
Definition
depends on temperature, salinity, and pressure
Cold water holds more gas
Less saline water holds more gas
Deeper water holds more gas
Term
What processes control the concentrations of O2 and CO2 in seawater? How?
Definition
They are controlled by biological processes
-Most important life processes in the oceans are photosynthesis and respiration
Term
How does the concentration of O2 and CO2 change with depth? Why?
Definition
Photosynthesis produces oxygen and at the surface it is exchanged with atmosphere
Respiration occurs but photosynthesis wins
Farther from light photo lose eventually increases a little with less animals, higher pressure, and deep water from surface
Term
Why is the behavior of CO2 unique is seawater?
Definition
60 times as much CO2 in the oceans as in the atmosphere
CO2 not only dissolves, but also reacts with H20 to form H2CO3 carbonci acid and dissociates to form the anios HCO3 bicarbonate and CO3 carbonate
Very important in regulating the chemistry of seawater and of the atmosphere
Term
How does CO2 dissociate in seawater?
Definition
Term
What is an acid? What is a base?
Definition
Acid- a compound containing hydrogen that, when dissolved in water, sets hydrogen ions (H+) free, increasing the number of such ions per unit of water mass strong acid readily releases its H ions
Base- a compund that release hydroxyls ions LIke acids, some bases are strong
Water itself is neutral, at hydogen ion it become acid
Term
What is the pH? What is a pH scale?
Definition
pH scale, abundance of H+ ions
pH 7 neutral 0 acidic
logarithmic
Surface 8.1 deep seawater 7.8 (low enough to allow the dissolution of CaCO3
Term
What is buffering? Explain how the carbonate buffering system works. Why is it important? Why deep waters are not very acidic?
Definition
Buffering- Reactions involing dissolved CO2 species minimze changes in pH of teh oceans
Keep the ocean from becoming to acidic or basic
If the pH of the ocean decreases(becomes too acidic), the excess H+ combines wiht HCO3 to form H2CO3
If the pH of the ocean rises (becomes to basic, consuming H+) some of the H2CO3 dissociates to form additional H+ and HCO3
Deep water is not acidic because of the buffering action of CaCO3
Term
What is a reservoir? What are some of the reservoirs in the hydrologic cycle? The hydrologic cycle moves water between the ocean, the atmosphere, and the continents. How does water move between the different reservoirs (through which processes)?
Definition
Reservoir- A container in which a substance is stored (e.g., the hydrologic cycle, water is contained at least temporarily, in reservoirs such as streams, atmosphere, ground water, glaciers,lakes, and the ocean).
The hydrologic cycle- evaporation, transpiration, wind rain and snow, groundwater flow
Term
Which four elements make up 99% of the mass of living organisms?
Definition
Carbon, Oxygen, Hydrogen, Nitrogen
Term
What are the main categories of molecules that make up organisms?
Definition
Term
What are nutrients? Which are the main nutrients essential for life in the oceans? Which nutrient is almost always abundant with respect to the needs of algae? What does ‘micronutrient’ mean?
Definition
Nutrients- any organic or inorganic compound used by plants in primary production. Nitrogen and phophorus compounds are important examples
Carbon,nitrogen and phosphorus
Inorganic compounds are needed by algae
Micronutrients- present in short supply
Term
How does the distribution of nutrients in the water column compare with dissolved oxygen and why?
Definition

[image]

Blue line of nutrients mimics the profile of CO2
High oxygen at the surface because of photosynthesis
Photosynthesis Increases O2 Decreases CO2 and nutrients
Decrease in deep water because they come from the surface
Oxy Min and Nutrient Max is at 1 Km depth (same depth as thermocline and pycnocline) at base of pycnocline, these gases and organisms pause there for a second, which builds up or consume oxygen and nutrients
Then farther of away from the surface respiration dominates Decreases O2 and Increases CO2 and nutrients
That’s why areas of upwelling are very productive

Term

Briefly describe the general model of biochemical recycling in the ocean system.

Definition
[image]Inorganic matter (nutrients) becomes organic with plants
Bacteria transform detritus into inorganic material, and transform it back into nutrients
Term
What is energy? Can organism create new energy? What is the ultimate source of energy for all organisms?
Definition
Energy- is the capacity to do work
The ultimate source of energy for living organisms is the sun
Organisms can not create energy but they can transform one kind of energy to a different kind
Term
Which organisms directly use solar energy? How?
Definition
Producers (some bacteria, algae, plants) trap light energy with chlorophyll and change it into chemical energy- which is used to build organic food molecules used by them or eaten by consumers
Term
Define photosynthesis and chemosynthesis.
Definition
Photosynthesis- is the process through which light energy is used to synthesize molecules rich in stored energy

Chemosynthesis- the production of usable energy directly form E-rich inorganic molecules
Term
Define primary productivity. What units are used to express it? Which organisms are responsible for primary productivity in the oceans?
Definition
Primary productivity- the synthesis of organic materials from inorganic substances through photosynthesis or chemosynthesis
expressed in gC/m^2/yr
Phytoplankton- produces 90-96% of oceanic organic carbon
Seaweeds-2-5% Chemosynthesis 2-5%
Total ocean productivity ranges 75-150 gc/m2/yr
Term
Compare marine and terrestrial primary productivity.
Definition
Marine produces are much more efficient in their productions of food
-Rapid turnover time indicates that nutrients cycle from producer to consumer and back much more quickly in marine ecosystems
Total mass of a primary producer is assumed to be 10 times the mass of the C it fixes
Marine 35-50 Terrestrial 50-70
Term
What are some of the direct ways to measure primary productivity?
Definition
Plankton nets are used to capture plankton. Analysis of the amount and type of organisms captured reveals much about the productivity of the area
Carbon taken up by primary producers can be measured to calculate the rate of primary productivity using radioactive carbon
Bottles can be used to measure the O2 produced by phytoplankton which indicates the amount of organic C synthesized
Term
What are some of the indirect ways to measure primary productivity?
Definition
Satellites- can estimate the chlorophyll content of ocean water
Term
What is a limiting factor? What four factors do algae need to grow? Are any of these factors limiting? Why and how?
Definition
Limiting Factor- a physical or biological necessity whose presence in inappropriate amounts limits the normal action of organisms (primary productivity)
Algae needs 1.water 2. CO2 3. Inorganic nutrients 4. Sunlight
Water is not a limiting factor in ocean
CO2 is almost never limiting
Sunlight can be limiting
Inorganic nturients N,P, Si, changes in their level increase and decrease productivity
Term
Define autotrophs, heterotrophs, primary producers, primary consumers, secondary consumers.
Definition
Autotrophs- primary producers: photosynthetic and chemosynthetic organisms (they make their own food)
Heterotrophs- organisms that must consume other organisms because they are unable to synthesize their own food molecuels
Primary producers- are mostly chlorophyll-containing organisms
Primary Consumers (herbivores) animals that feed on primary producers
Secondary Consumers- animals that feed on primary consumers
Term
How much mass and energy are transferred between trophic levels?
Definition
Total mass of consumers becomes small as energy flows toward the top of the pyramid (less but bigger animals)
-Only 10% of the mass and energy from the organisms consumed is stored in the consumers
Term
Why do we tend to use food webs rather than food pyramids in describing real communities?
Definition
Because organisms can eat others from different levels beneath them, and others on their levels
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