Unit 2 Oceanography Test – Flashcards
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Define coast
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from the ocean inland to where ocean processes no longer immediately affect the land
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Define shore
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Where ocean meets land, limit of high tide
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What are the differences between erosional and depositional coasts
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Erosional - (70% of coastlines) and more erosion occurs Depositional - (30% of coastlines) more deposition occurs
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What are the age differences between depositional and erosional coasts
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Erosional coasts are generally new coasts while depositional are older, steady coasts
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What is an erosional coast
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where erosion occurs to the coastline due to excessive waves, wind abrasion, or any other constant factor eating away at the coast.
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What types of geological features would you expect to find along an erosional coastline
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sharp sea cliffs, sea caves, sea stacks, wave-cut platforms and occasionally natural bridges and blowholes
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What processes are involved in turning an erosional coast with headlands and bays, into a straight coastline
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wave refraction create bays with small beaches, which results in wave energy being bent away from these bays, eventually creating straight coastline
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What is a depositional coast
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growing coasts of accumulating sediments from land and sea or the remains of biological organisms
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What type of geological features would you expect to find along a depositional coastline
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beaches, sand spits/bay mouth bars, barrier and sea islands and deltas (Covered with sand)
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What is the source of most sand on continental beaches
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sand that is brought in by rivers
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Sediment size related to slope of the beach
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Fine material - flatter beach Coarse material - steeper beach
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What is a longshore drift
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movement of sediments along the coast
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What causes longshore drift to occur
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wave action
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What are the two components of longshore drift
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longshore currents and beach drift
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What is a longshore current
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ocean current that moves parallel to shore
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What generates longshore currents
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incomplete refraction of waves approaching the beach at an angle
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How do longshore currents move sand along the beach
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they move the sand in the direction the current is flowing and constantly transports it down the shore line
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What is beach drift
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the movement of sand particles down a beach
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What is a groin and how does it impede longshore drift
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It is a man made structure that slows the waves down and keeps the longshore drift from washing beaches or sand away from certain areas
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What is a sand spit and why does it form
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deposition landform which is mainly found off coasts where re-entrant happens by long shore drift
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What is a bay mouth bar
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It is a sand spit that completely closes and cuts off the main body of water
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What are barrier and Sea islands
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barrier islands - islands that are oriented parallel to the mainland and made from depositional sand sea islands - islands that were originally attached to the mainland and have a rock core instead of sand (erodes faster than barrier islands)
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What are estuaries
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semi enclosed basin where river water mixes with ocean water
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How does the salinity in an estuary differ from a river or ocean
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The salinity is mixed from the fresh river water and salty ocean water making it slightly salty. So saltier than rivers and less salty than oceans.
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What is a delta and what causes them
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a landform that forms at the mouth or a river and is formed by sediment laden rivers enter calm water and dump the sediments
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What are the two types of biological coasts
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coral reefs and mangrove coasts
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What are rip currents
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strong narrow seaward currents that flow through surf zones
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How do you escape a rip current
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swim slowly parallel to shore until you escape the rip current
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What is the chemical structure of the water molecule
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H2O
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Why does the structure of a water make it a polar molecule
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Because one side is positive (Hydrogen) and the other is negative (Oxygen).
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How does water's polar nature allow it to bond to ther water molecules
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because the negative and positive sides bond with opposite charges then the Hydrogen is attracted to the Oxygen end of another water molecule, allowing them to bond creating a HYDROGEN BOND
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How is water unique because of its surface tension
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The surface tension of water is the highest of all common liquids
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What is heat capacity
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amount of heat (in calories) required to raise the temperature of 1 gm of a substance by 1 C.
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Does water have high low heat capacity and how does it affect water's temperature with heat input
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high heat capacity, preventing it from changing temperatures drastically from day and night. The high heat capacity is due to the hydrogen bonds.
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What is thermal inertia
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the resistance to change in temperature with gain or loss of heat
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What are water's three common states of water
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gas, liquid, solid
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Why is water unique due to its physical states
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water is unusual because when it gets colder and freezes then it actually becomes less dense. most other substances become more dense
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How does the density of water change when going from room temperature to its freezing point
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it becomes more dense up until it freezes. once frozen it reaches its least dense state
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What is the temperature that pure water is most dense
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4 degrees C
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Why is water unusual between 3.98 and 0 degrees C
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even though it is getting cooler, this is where water starts becoming less dense as it begins to expand and freeze
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What happens to water's volume in the temperature range of 3.98 and 0 degrees C
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it will increase and expand
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How does water's molecular structure change as it cools
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it expands as the hydrogen bond angles change to 109, causing more space between each hydrogen bond
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What is Latent Heat of Fusion
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heat removed during freezing or added during thawing that produce change in state but not change in temperature
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What is Latent Heat of Vaporization
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heat added during evaporation or released during condensation that produce a change in state but not a change in temperature
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How much heat is required to change ice into liquid water
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80 cal/gm 0 degrees C
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How much heat is required to change liquid water to water vapor
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540 cal/gram at 100 degrees C
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What characteristics or water molecules makes it a universal solvent
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its polar nature breaks up the compounds help together by ionic bonds, causing more substances being able to dissolve in it.
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What is salinity
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the total concentration of dissolved organic solids in water
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what are the different units used for salinity
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%o, ppt, parts/thousand
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Ho does salinity change the boiling point, freezing point, and heat capacity of water
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boiling point - increases heat capacity and freezing points - decreases
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Which dissolved ions are first and second most common in seawater
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(Most abundant) 1-chloride, 2-sodium, (Trace elements) 3-sulfate, 4-magnesium, 5-calcium, 6-potassium, 7-bicarbonate
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What is the average salinity of the ocean
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34.7 ppt
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Where does the salinity of the ocean originate from
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weathering and erosion from rocks
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Where does the chloride in the ocean originate from
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outgassing on land and ocean floor
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What is the definition of "mixing time"
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how long it takes a substance to mix (circulate) throughout the ocean
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What is the mixing time of the ocean
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1600 years
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What is "residence time"
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the average length of time a dissolved substance spends in the ocean
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How does residence time relate to how well components of seawater are distributed throughout the ocean
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depending on the rate at which the elements mixing time is depends on how distributed it is, as most of the elements residence time is much longer than oceans mixing time
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How is residence time related to mixing time
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depending on the residence time, the elements could outlast the mixing time and become more evenly distributed throughout the ocean
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What is the principle of constant proportions
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the proportion of major elements in seawater remains nearly constant even though the total salinity may vary with location
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How can you use the principle of constant proportions to measure one of the dissolved solids, then use that to get complete salinity
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since the major elements in seawater is constant, you can get measurement of one element then use a formula to determine the complete salinity
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What processes happen at the surface of the ocean that change the surface salinity, and how the salinity is affected by them
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precipitation, river input, or melting ice - Lowers salinity evaporation or ice formation - Raises salinity
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What are the types of instruments used to measure salinity and which property of seawater the instrument uses to measure salinity
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refractometer - refraction, salinometer - conductivity, hydrometer - specific gravity
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What is the concentration of CO2 in the atmosphere compared to the ocean
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atmosphere - .038% ocean - 15%
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How do O2 and CO2 vary with depth
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amounts of O2 decrease with depth and CO2 amounts increase
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How do temperature, salinity, and pressure affect the concentration of gases in the ocean
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low temp, fresher water - more gas dissolved warm temp, saltier water - less gas dissolved
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Which climatic region of our planet would allow the most gas to be dissolved based on temp and salinity
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polar regions - due to colder, fresher water
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What is the pH scale used for
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to determine the acidity of the water
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What is the average pH of seawater and is it alkaline or acidic
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~8 and is slightly alkaline
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What is the relation of pH to the acid-base balance of the ocean
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the acid-base balance of the ocean is directly measured by the pH scale
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What range on the pH scale is considered acidic and which is considered basic (or alkaline)
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below 7 is acidic above 7 is basic or alkaline 7 is neutral (pure water)
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How increases and decreases in dissolved CO2 affects the pH of the ocean
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when CO2 dissolved in the ocean it can go through chemical reactions and change the pH of the ocean
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How is the pH of our ocean changing due to the extra CO2 being absorbed by the ocean
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more CO2 means lower pH (more acidic) less CO2 means higher pH (more basic)
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What are the 3 main physical properties of the ocean
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salinity, temperature, density
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What are the names of the 3 layers found in the ocean from the surface to the bottom
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surface layer (mixed layer) transitional layer (thermocline) deep layer
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Why is the surface layer often called the mixed layer
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there is mixing by waves that often causes the temp and salinity to be constant
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What kind of variabities do temperature and salinity typically have in the surface layer
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salinity - rainfall, evaporation, ice melting and ice forming temperature - solar radiation throughout seasons of year
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How does the mixing of waves affect the salinity, temp and density of the surface layer
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the temperature and salinity remain constant at the surface layer but the density increases due to pressure increases from depth
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How can you identify the surface layer in a vertical temp profile
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the surface temps vary depending on latitude (warmest in tropics and coldest at poles)
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How does the density in the mixed layer and why
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density increases with depth due to the pressure
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What is the halocline and how does salinity change within it
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the halocline is the transitional layer when dealing with salinity. the salinity increases with depth due to lack of fresh water variables
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What is the thermocline and how temperature changes within it
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thermocline is the transitional layer when dealing with temperature. the temperature decreases with depth due to lack of sunlight
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How do you identify the thermocline in a vertical temperature profile
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the depth and the temperature will be opposite making it an inverse relationship
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What is a pycnocline and how does density change within it
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pycnocline is the transitional layer when dealing with density. density always gradually increases with depth due to pressure increases
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What is the % of water is in the deep zone/layer of the ocean in the mid to low latitudes
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80%
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What are the relative variabities that temperature and salinity have in deep layer
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there are very little variablities of temperature and salinity in the deep layer. this is due to the lack of sunlight (temperature) and fresh water variables (salinity) that deep
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What is an XBT and what property does it measure
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Expendable Bathythermograph - measures subsurface temperatures
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Does an XBT measure surface values or values over a depth, and does it measure globally or at a single point
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it measures both surface and depth values but mainly for depth, and it measures the temp in a single point
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What is an AVHRR and what property does it measure
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Advanced Very High Resolution Radiometer - it measures surface temperature. it determines surface values only and measures globally
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What is the definition and formula for density of seawater
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mass per unit volume of water D=M/V
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What properties affect the density of seawater
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temperature, salinity and depth (pressure)
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What are the relationships that temp, salinity, and pressure have on density
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direct relationships - salinity and pressure go up, so does density inverse relationships - temperature goes up and density goes down
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Which combination of temperature and salinity produces the least and most dense water
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least - warm, less salty water more - cold, saltier water
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What is electromagnetic radiation
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the radiant energy Earth receives from the sun
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What kind of waves make up the electromagnetic spectrum
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radio, television, microwave, infrared, visible light, U-V, X rays
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Which wavelengths of visible light penetrates deepest in the ocean
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blue is the deepest followed by green and violet
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which wavelengths get absorbed the quickest in the ocean
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infrared then red
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what are photic and aphotic zones
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photic - lighted water (avg 100m depth) aphotic - no light (greater than 100m depth)
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where are photic and aphotic zones found vertically in the ocean
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photic is on average the first 100m down then everything below that is aphotic
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how does the amount of electromagnetic energy that reaches the surface of Earth vary with latitude
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there are more at the tropics due to being more vertical and less at the poles due to a lower angle being presented
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What is heat budget
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The total of incoming and outgoing radiation. (earth gaining heat from incoming short-wave radiation and losing heat from radiating long-wave)
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how does the tilt of our planet affect the amount of energy that reaches the surface of our planet during the different seasons of the year
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during summers that part of the planet is towards the sun and in the winter it is away from the sun.
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which latitudinal region on Earth has a net gain in heat. which has the net loss of heat
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tropics - net heat gain poles - net heat loss
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what are the latitudes on our planets that are balanced in regards to heat gain and heat loss
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38 degrees N and 38 degrees S
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which is more important in balancing our latitudinal heat imbalance on our planet, ocean or atmospheric pressure
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atmospheric pressure as 2/3 is transfered by air and only 1/3 is transfered by ocean
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what is the difference between weather and climate
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weather - the state of the atmosphere at a specific time and location climate - the long term average of weather at a location
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what is atmospheric circulation
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wind
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what happens to the volume and density of air as it is heated or cooled
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heated - becomes less dense, rises and expands cooled - more dense, sinks and compresses
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what is the coriolis effect
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the tendency for any object to deflect from its course due to the rotation of the Earth (northern hemisphere veers right and southern hemisphere veers left)
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what are the names of the circulational cells
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hadley cell, ferrel cell and polar cell
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which are the names and latitudinal regions that each of the circulational cells cover
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hadley - equator (0-30 degrees N and S) ferrel - 30 - (50 or 60) degrees N and S polar - (50-60) - N and S poles
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what are the direction of the dependable surface winds of each atmospheric circulation cell
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hadley - easterly trade winds ferrel - westerlies polar - polar easterlies
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what are doldrums
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rising air between the two hadley cells
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what is the ITCZ and what are the surface winds converging there
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Intertropical Convergence Zone - slack winds
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is the air moving vertically or horizontally in the doldrums/ITCZ
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vertically
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what kind of atmospheric conditions are common in the doldrums/ITCZ
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calm and wet
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at which average latitude does the doldrum/ITCZ occur and why they occur at that latitude
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the equator, and occurs because of strong heating that causes surface air to rise
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how does the locations of the doldrums/ITCZ vary between summer and winter
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it will shift between 5 degrees N and S
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what are the names of the two circulation cells on both sides of the doldrum
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hadley cells
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what are the meteorological and thermal equators
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an imaginary line of thermal equilibrium that is not a straight line and moves slightly N in our summer and slight S in our winter (avg ~5 deg N)
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how does the meteorological (thermal) equator correlate with the doldums/ITCZ
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the ITCZ is actually located at the thermal equator instead of the geographical equator
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how does the meteorological (thermal) equator differ from the geographical equator
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the geographical equator is set at 0 deg and the thermal equator fluctuates between 5 deg N and S
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what are horse latitudes and what causes them to form
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the latitudes between where the hadley and ferrel cells converge. they are formed by the sinking air (moving vertically downward)
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what kind of atmospheric conditions are common in the horse latitudes
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warm and dry
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what are monsoons and what regions are most affected by them
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patterns of wind circulation that changes with the season - doldrums (trade winds) region
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how do the winds and atmospheric conditions between summer and winter in the monsoons
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summer - more nothern hemisphere monsoons meaning wet summers winter - southern hemisphere monsoons meaing dry winters
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what are extratropical cyclones and where do they tend to form
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cyclones that form at the boundary between the polar cell and ferrel cell - polar front
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what are the different regional names given to tropical cyclones
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typhoon, hurricane, tropical cyclone, willi-willi
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what are the different directions that cyclones tend to rotate when in the northern and southern hemisphere
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Northern - counterclockwise Southern - clockwise
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which regions of the world do tropical cyclones tend to form in
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typhoon - western pacific hurricane - eastern pacific or atlantic tropical cyclone - indian ocean willi willi - south western pacific around australia
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what is the necessary ocean temperature that is needed to spawn a tropical cyclone
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temperatures exceeding 26 C
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what is a storn surge
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low pressure in center of cyclone that causes water to dome up
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how is the movement of a storm surge tied to a tropical cyclone
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it travels witht he tropical storm and filters upward causing a water dome to be sucked upwards as well
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what happens to hen it comes ashore
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it carries the dome of water ashore and can cause tremendous damage
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why is the storm surge often more dangerous than the winds of a tropical cyclone
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wind an destroy property but storm surges can also be destructive with their large heights of the domes. it also leads to severe flooding which can have a long term effect.
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which way is a northerly wind blowing from
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north to south. whatever the type of wind is called is based on were it is blowing from
