Homework-Answer this question and email it to   biovcc@Gmail.com

HW 1

1. Scientists that study forms of marine life that lived more than approximately 200 million years ago usually have to obtain fossils not from the sea floor, but from areas that were once undersea and been uplifted onto the continents.  Why do you think this is?

2. The winter of 1984-85 was particularly cold in Europe. The northern part of the Black Sea, froze, which is rare in the normally mild climate.  The Adriatic Sea, located east of the Black Sea, has just as cold of a winter but never froze.  Te Black Sea has an unusually low salinity of about 18ppt.  What would you say about the salinity of the Adriatic Sea?

Lecture Notes 1—

 

A Unique Planet    Life would not be possible without large amounts of water.  Water has the ability to retain heat, moderate temperature, dissolve many chemicals, and suspend nutrients and wastes.   A Unique Planet    All life, from a jellyfish to a dusty desert weed, depends on saline water within its cells to dissolve and transport chemicals..indicating that simple, self-replicating-living molecules arose somewhere in the early ocean.   A Unique Planet    How long agoprobably at least 3.4-3.5 billion years ago as the oldest fossils yet found indicate.     

 The most striking and distinctive feature of our planet, when viewed from space, is the amount of water on its surface. Its called the water planet. And, while some is contained in clouds as water vapor and a few percent is present in lakes, rivers ice caps and in cavities of pores of rocks, most is contained within the oceans. The sea probably played a part in man's life and experience from the very earliest times, even his prehuman ancestors are likely to have included shellfish from the shore in their diet.       

Water transportation was used at least since 50000 years ago to colonize Australia and maybe even longer but little trace remains because of the materials used for primitive boat building, reeds, wood, skins rapidly decompose. While the Greeks, Pacific Islanders and Vikings were responsible for some of the earlier spectacular maritime achievements, the Portuguese sea men were the first true pioneers of European oceanic exploration. Sent out by Prince Henry in 1420's they continued new discoveries, and charted these with considerable skill. In the 1460's they devised a system of nautical astronomy to improve navigation.           

The map shows the world known to Homer at about that time, and shows that knowledge of the seas was centered in the Aegean, and extended generally throughout the eastern Mediterranean. The Greeks of that time imagined the world to be a large disk with upturned edges, with the center of the disk in the Aegean, surrounded by a river.    

 Although the Phoenicians had traveled into the Atlantic centuries earlier, the Greeks were probably unfamiliar with the Atlantic Ocean, or any seas beyond the Mediterranean. Between the eighth and sixth centuries BC, Greeks of the historic period began voyaging more extensively beyond the Aegean, although not venturing out of the Mediterranean until the fourth century BC..     

  Renewed interest in natural history began to increase by the 16th century, and over the next few hundred years there were many studies carried out by what we would today call amateur naturalists.   

These were usually professional men in other fields, often physicians or explorers, but generally were individuals not specifically employed to carry out natural history studies.

  Notable among these are the explorations of Humboldt and of James Cook, who made extensive voyages and observations of the natural world.     

  One of the early professional naturalists that made significant contributions to marine biology was Charles Darwin. Darwin, most famous for his later works on theories of evolution, was commissioned early in life as a naturalist on the 

  The British ship HMS Challenger investigated the oceans worldwide between 1872-1876, finding a large number of new species. Sir Charles Wyville Thomson (Professor of Natural History at the University of Edinburgh, and director of the civilian scientific staff on the Challenger) published the findings of the Challenger expedition in a series known as the Challenger Reports. 

    Until the middle of last century, marine biologists relied primarily on nets, grabs, and dredges to collect samples in almost every marine habitat except the intertidal zone, where collections could also be made by hand and organisms could be directly observed. As an example of the ships and techniques, the U.S.S. Albatross of the United States Fish Commission carried out a number of expeditions from 1887 to 1925. Some of the equipment used on the Albatross are pictured below     

   In 1934, zoologists William Beebe and Otis Barton were the first to observe relatively deep sea habitats directly aboard the "bathysphere", which remained tethered to a surface ship during the entire dive. 

 They reached a depth of 923 meters (3,072 feet). The advent of modern Self Contained Underwater Breathing Apparatus (SCUBA), underwater photography, and manned submersibles have allowed us to see firsthand much of the marine environment that we previously could not observe.       The development of a wide variety of electronic measuring devices and instruments, unmanned submersibles, and remote sensing by

satellites and aircraft has also greatly increased our ability to measure and study parts of the marine environment that are difficult to observe in person.   

Even so, because of logistical problems associated with conducting research in much of the marine environment, our knowledge of conditions in most of the seas and oceans lags behind our knowledge of the terrestrial environment.
 
    By the 1480's a pilot could calculate his latitude. Longititude could not be measured yet so "running down the latitude" was practiced...sailing to the latitude of landfall, for three to four hundred miles seaward and then sailing due east or west to the landfall. Columbus used his method on his return voyage from the New World.

  It wasn't until 1760+ that John Harrison's fourth chronometer and the lunar distance method of calculating longitude provide answers to measure longititude at sea.   Latitude and Longitude  1st and 4th Chronometer by John Harrison     

 Albatross   In August 1882, the United States Commission of Fish and Fisheries launched the first vessel built especially for marine research by any government—the steamer Albatross. Perhaps even more impressive than being the first government vessel equipped throughout with electric lights, Albatross has been credited with discovering more new marine species than any other research vessel.   

  The American Navy's' ship the Blake carried out research from 1877-80 in the Caribbean gulf of Mexico and coast of Florida and from there the science continued to flourish... Note names!

    Pathfinder was the first survey ship to have a nautical chart printing press installed onboard. During World War II, the vessel churned out thousands of charts for fleet units. Captain Junius Jarman of the C&GS was instrumental in developing techniques for chart printing in a shipboard environment.   Latitude and Longitude  Longitude  On the globe, lines of constant longitude ("meridians") extend from pole to pole, like the segment boundaries on a peeled orange 

  Latitude and Longitude  Every meridian must cross the equator.  

 Since the equator is a circle, we can divide it--like any circle--into 360 degrees, and the longitude of a point is then the marke

d value of that division where its meridian meets the equator.

   Latitude and Longitude  Any location on Earth is described by two numbers--its latitude and its longitude.   

If a pilot or a ship's captain wants to specify position on a map, these are the "coordinates" they would use.     

  Latitude and Longitude  On a globe of the Earth, lines of latitude are circles of different size.

  The longest is the equator, whose latitude is zero, while at the poles--at latitudes 90° north and 90° south (or -90°) the circles shrink to a point.   

 Did you know that you can use the stars to tell directions at night? The North Star, or Polaris, is usually within 1-2 degrees east or west of true north. Polaris is at the top of the handle of the Little Dipper, a constellation that is easy to find in the Northern Hemisphere.    

   You can also use the North Star to determine latitude in the Northern Hemisphere. Use an astrolabe, used to determine the altitude of objects above the horizon, to find your latitude. You can make your own simple astrolabe using a protractor, plastic straw, 12-inch piece of string, and a metal weight (a small bolt or a washer works well). Tie one end of the string to the hole in the middle of your protractor. (If there is not a hole, drill one in the center of the flat-edged piece on the protractor.)          

  Latitude and Longitude  1st and 4th Chronometer by John Harrison  Latitude and Longitude  What that value is depends of course on where we begin to count--on where zero longitude is.  

 For historical reasons, the meridian passing the old Royal Astronomical Observatory in Greenwich, England, is the one chosen as zero longitude.   Latitude and Longitude  Old Royal Astronomical Observatory in Greenwich, England,  Latitude and Longitude  Located at the eastern edge of London, the British capital, the observatory is now a public museum and a brass band stretching across its yard marks the "prime meridian.   Tourists often get photographed as they straddle it--one foot in the eastern hemisphere of the Earth, the other in the western hemisphere.    Latitude and Longitude    A lines of longitude is also called a meridian, derived from the Latin, from meri, a variation of "medius" which denotes "middle", and diem, meaning "day."   The word once meant "noon", and times of the day before noon were known as "ante meridian", while times after it were "post meridian."  

 Today's abbreviations a.m. and p.m. come from these terms, and the Sun at noon was said to be "passing meridian".   Latitude and Longitude  All points on the same line of longitude experienced noon (and any other hour) at the same time and were therefore said to be on the same "meridian line", which became "meridian" for short.

 Latitude and Longitude  Time Zones   

   On the Mississippi river in the 1850s, the leadsmen also used old-fashioned words for some of the numbers; for example instead of "two" they would say "twain". Thus when there was only two fathoms left under the boat they would call "by the mark twain!". The American writer Mark Twain, a former river pilot, likely took his pen name from this cry.   

  Sonar  How does Sonar work?   Sonar is a device that is used to detect objects through sound waves.

  There are two main types of sonar: Active and Passive.   Sonar technology enters a signal into the water in a narrow beam which has the speed of about 1500 m/s.    

 Sonar  Ocean Floor Contour using Sonar  Sonar  If there is an object in the beam, its sends sound energy back to the sonar dish.   Then the distance is calculated by range = sound speed x travel time / 2.   In active sonar a pulse signal is sent to a transducer which changes the electrical signal into a sound signal.   

      Sonar  After that it is put out into the water and it detects returning echos.   A receiver amplifies the soft echos and measures the range of each object.  

     Sonar  Old Method     

   Sonar  New Method up to 121 beams.     

   Sonar  Geosat from Orbit!        Sonar  Geosat Image  

     Radar  Radar works by sending out a radio wave at a very high frequency.  

 When the radio signal hits raindrops part of the signal bounces back to the radar.

  The signal travels at the speed of light (over 350,000 kilometers per second!).            

   Radar  Knowing exactly how fast the signal is travelling, means that we can tell how far away the rain is by timing how long it takes for the signal to travel to the rain and then bounce back to the radar.   This happens so fast that most radars send out about 1000 signals (called pulses) each second!!     

     Loran  A long-range radio navigation position fixing system using the time difference of reception of pulse type transmissions from two or more fixed stations. 

 This term is derived from the words long-range electronic navigation.          

     All radionavigation systems, including GPS, have their weaknesses. On February 7, 2008, the U.S. Department of Homeland Security (DHS) announced that it would begin implementing Enhanced Loran (eLoran), an enhanced and modernized version of Loran-C, as the U.S. national backup system. This independent, positioning, navigation, timing, and data delivery system would mitigate the safety, security, or economic effects of a loss of GPS for critical infrastructure applications, especially those that require precise time and frequency.  GPS  GPS system of satellites--the Global Positioning System. That network of 24 satellites constantly broadcasts its positions, and small hand-held receivers exist which convert those signals into positions accurate within 15 meters or about 50 feet.  

   GPS  In circular orbits at distances of about 4.1 Earth radii (26,000 km or 16,000 miles), GPS satellites continually broadcast their precise locations, and these can be read by small portable receivers, relatively inexpensive.   

GPS  Using a built-in computer, these receivers then derive their own precise position on the ground, within 10-50 meters.  .  

   Russia operates its own system, GLONASS, and European countries are planning a third on  GLONASS constellation status, 13.01.2009г.  Total satellites in constellation 20 SC Operational 16 SC   In commissioning phase 3 SC   In maintenance 1 SC   In decommissioning phase -
 
e.       GPS  Originally developed by the US Department of Defense (whose users derive from them even more precise positions), the GPS satellites are widely used by the public--by ships at sea, airplanes, hikers in the wilderness, even drivers trying to navigate large cities   

  By means of four or more satellites, an absolute position in a three dimensional space can be determined. A 3D-position fix also gives the height above the earth surface as a result.
  By constantly recalculating its position, the GPS receiver can additionally determine the speed and direction of a movement (referred to as "ground speed" and "ground track").

   
            Introduction To the Oceans  About 71% of the surface of the planet is covered in salt water.   Beneath the depth averages 3,8 km giving it a volume of 1370 x 106 km3.   Since life exists throughout this immense volume, the oceans constitute the single largest repository of organisms on the planet.   Introduction To the Oceans  These organisms include representatives of all phylums and are tremendously varied but all are subject to the properties of the sea water that surrounds them.   Many features common to these plants and animals are the results of adaptations to the watery medium and its movements.   Introduction To the Oceans  Its necessary therefore, to examine the physical and chemical conditions of seawater and aspects of its motion (oceanography) and look at the environment where the organisms live.

   Introduction To the Oceans  Hydrologic (Water) Cycle  Introduction To the Oceans  Where is all the Water?  Introduction To the Oceans  Ocean Basins  Introduction To the Oceans  Ocean Basins  Introduction To the Oceans  The mean depth is 4km (2.5 miles)and its interconnected from the Arctic to Antarctic.   Seawater flows freely among the basins transporting dissolved materials, heat and marine organisms.   Seawater mixes from basin to basin/per 1000 years but regional characteristics of the seawater do exist.   Introduction To the Oceans  The major basins are the Pacific, Atlantic, Indian, Arctic, Southern ocean and the boundaries are artificially defined.         

   Introduction To the Oceans  Seawater mix  Movement of water moderates world climate by distributing heat from equatorial water to the poles.   Warm currents flow toward the poles from the equator (Gulf Stream) heating northern latitudes.   Cold water from the Arctic and Antarctic basins flow beneath the oceans surface toward the tropics...cooler water near the equator.   Introduction To the Oceans  SEA LEVEL  The sea level has undergone dramatic changes. 15000 years ago 120m below present level.   As it fell portions of the continental shelf were exposed changing position of coastline.  Ice age/Wisconsin glacial period, the ocean water froze into glaciers.  Introduction To the Oceans  SEA LEVEL    Introduction To the Oceans  It is still rising.  The rise slowed 3000 years ago and has only risen 10m since.   CO2 is  warming the Earth and the ice could melt and flood low lying areas in the next 1000 years.. Green House effect.         

       Introduction To the Oceans  The Ocean Floor  Prior to the 1920's, they used weighted rope to probe depths.   1920's the echo sounder (SONAR-(sound navigation and ranging) which analyzed sound waves which bounced off the oceans bottom and returned to the ship.   The Meteror (1925-7) did the 1st ocean survey with sonar.   

  Introduction To the Oceans  Common topographical features of the oceans include: Continental margin and deep sea as the major divisions. Continental Margin  Continental shelf-underwater extension of the continental land mass.

  8% of the total surface area of the world ocean, yet its one of the most productive parts of the ocean.   

It gradually drops down to the 100-200m depth.  Introduction To the Oceans  Formation of Continental Shelf

  Introduction To the Oceans  Continental slope begins where continental shelf plunges down.  

 As the steepness decreases, this zone is called the continental rise.   Introduction To the Oceans  Locations of Continental Shelfs  Introduction To the Oceans  Soft sediment of the shelf exposed to erosion from rivers and then the glaciers started to melt, excess water cut canyons into the shelf.   

Ocean refilled, flooding shelf and forming underwater canyons.  

 The rise slowed 3000 years ago and has only risen 10m since.    

 Introduction To the Oceans  Underwater canyons occur in the margins which resulted from when the  ocean level was lower with rivers flowing over them eroding the soft sediments making deep gouges.    Underwater landslides along the sides of the canyons make the canyon bigger    Introduction To the Oceans     

 Introduction To the Oceans  Types of Reefs  Fringing-along the land  Barrier-a lagoon between the land and reef  Atoll-a reef around a lagoon (formally an island since eroded.   Introduction To the Oceans  Types of Reefs     

 Introduction To the Oceans 

Trench Formation   Converge: one plate dives under another, crumples and forms trenches...    

 Introduction To the Oceans  T

urbidity Currents  Avalanche-like sediment movements caused when turbulence mixes sediments into water above a sloping bottom.  Since this sediment-filled water is now denser than the surrounding water, thick, muddy water can run down the slope  at speeds up to 17mph.  These currents may have been responsible for enlarging submarine canyons  Introduction To the Oceans  Turbidity Currents    
 

PLATE TECTONICS  There are 8 major plates, up to 100 miles thick and move slowly.   

They know the direction and speed so can figure out what the continent was like before it moved.    

The Atlantic has been growing for 150 mil years.  The theory of continental drift or plate tectonics was only established in the 1960's.  200 million years ago, Pangaea fractured and started moving apart 180 mil. yrs ago.   

   Plates    
 PLATE TECTONICS  ALFRED WEGENER
(1880-1930) German climatologist and geophysicist who, in 1915, published as expanded version of his 1912 book The Origin of Continents and Oceans. This work was one of the first to suggest continental drift and plate tectonics.   
 PLATE TECTONICS  He suggested that a supercontinent he called Pangaea had existed in the past, broke up starting 200 million years ago, and that the pieces ``drifted'' to their present positions. He cited the fit of South America and Africa, ancient climate similarities, fossil evidence (such as the fern Glossopteris and mesosaurus), and similarity of rock structures.     
                                  PLATE TECTONICS
  The force that moves the plates over the semi-solid layer of the upper mantle /asthenosphere is the convection currents  (large temp. difference between the mantle and crust) and moves plates either   1. apart,   2. together or   3. laterally. 
                        Surtsey, Iceland;63.30 N 20.62 W;170 m elevation
This photo, taken on November 30, 1963, shows the sixteen-day-old cone which became the Island of Surtsey, off the southern coast of Iceland. Born from the sea, it has provided scientists a laboratory to observe how plants and animals establish themselves in new territory. The eruption began 130 m below sea level, where it proceeded quietly until the height of the volcano approached the sea surface. Then the explosive activity could no longer be quenched by the sea. A black column of volcanic ash announced the island's birth on November 14, 1963. Jets of dense black ash shot skyward and the towering eruption cloud rose to a height of 9 km. By April of 1965, ash had blocked sea water from the crater area. Lava flows became prominent, forming a hard cap of solid rocks over the lower slopes of Surtsey. This prevented the waves from washing away the island. The three and one-half year eruption was over in June 1967. Photo credit: Howell Williams
    PLATE TECTONICS
  1. apart  new material rise as magna /molten rock filling spaces (rifts form mid ocean ridge.  evidence  1965  research vessel Eltanin did magnetic studies        

    1969 Glomar Challenger did cores from Pacific-Antarctic ridge         

  1977 Project Famous  used submersibles      

  PLATE TECTONICS
  2.
  Converge  one plate dives under another, crumples and forms trenches...usually but not always (mountains)   the area is called a subduction zone  Island arcs formed/volcanos/ from turbulence from the melting of the descending plate.    PLATE TECTONICS
    3.
  Lateral-sideswipe and cause earthquakes volcanoes and deformations        

   PLATE TECTONICS
 
   Hydrothermal vents...water percolates into fissures around the rift valley, sinks and heats to 320'C in fissures (pressure).   The heated water dissolves metals and it rises to the seafloor surface,openings flow through the hydrothermal vents, mix with cold water, minerals settle to bottom forming deposits.  Robert Ballard witnessed milky bluish clouds spewing in a Pacific rift zone.                       Global Hotspots 

 
  Pacific Plate Motion  Moves W/NW at approx. 5-10 cm per year  

 Currently being subducted beneath the N. American and Eurasian plates (Aleutian Trench)  

 Moves over stationary hot spot in Earth’s mantle    Hot Spot Theory  1963- Proposed by J. Tuzo Wilson    Evidence:  Oldest Volcanic rocks of Kauai (most NW island) are dated at 5.5 million years old and greatly eroded.   

Oldest rocks of the Big Island are approx. 0.7 million years old. 

    Hot Spot: magma from within the Earth’s mantle pushes up the Earth’s crust resulting in the formation of an undersea volcano.     

   The Next Generation: Loihi  Located off the Southwest coast of Hawaii  Currently, 6000 ft above the sea floor (about 1km from the surface)   Predicted to poke through surface in about 1 million years. So, don’t make vacation plans just yet!    Caribbean
Tectonics  Puerto Rican

 


Tectonics and Seismic Hazard  Puerto Rican
Tectonics and Seismic Hazard 
    

 

. Seawater Chemistry
1.Q.
Does the saltiness of seawater vary?   Q. What makes seawater salty?  2.Q. Where does the salt come from?   Q. Is the ocean getting saltier?  3.Q. Do the components of seawater all behave similarly?  4.Q. How variable is the composition of salts in seawater?   5.Q. Which gases are dissolved in seawater?   6.Q. What role do the gases play in sustaining life in the ocean?   7.Q. Can the salt be removed from seawater?  
 
  

Water Chemistry Information
  Pressure   Air is .1% as dense as water and the ocean pressure is directly proportional to its depth and acts in all directions within the water   6/3/2002    Pressure  The atmospheric pressure is 1kg/cm2 (14.7lbs/sq in)= 1 ATM. An increase of 1 atm for each 33' or 10m and at 30m (100') the pressure is 4atm (1atm/10m + 1atm for air). Mariana trench 11,034m (36192')= 1000atm.   

          Pressure  This is known as hydrostatic pressure and because of it, many organisms restricted to particular level or depth and those that can go to all areas have evolved adaptations to compensate for the change.

     Density
  Salt water is 800x greater in density than air (supports big organisms).   The density is affected by temperature.   As water cools,     Density
           1.
     water molecules move closer, increasing density..    

      2.       4'C max density (1g/cm3)         

 3. cooler decreases density..ice= .92g/cm3 and is less dense so it floats.        

Temperature:  Water has a high heat capacity...ability to resist rapid temperature changes and is transferred by convection.    Temperature:  Temperature is the most important physical factor in the marine environment limiting the distribution of ocean life by effecting density, salinity, gas concentration in oceans.           

Temperature:  There is minimum vertical mixing because warm water (on top) can't replace cold water.   The thermocline is a narrow zone between warm surface water and cold bottom water. Temperature effects ectotherms and endotherms.          

Temperature 2  It also affects the density as does salinity so both salinity and temperature must be considered to work out density, salinity and oxygen level.  Variation of -2 (28) to +30 (86).    

 Temperature 2      Satellites are now used to monitor water temperatures  

 Agulhas Current    Gases
    Gases enter the ocean by diffusion from the atmosphere until it reaches saturation level...different for each gas.   Oxygen  

 O2 makes up 21% of the atmosphere but in the coldest oceans its less than 1% to as much as 9%.  

 Oxygen  O2 comes from photosynthesis in the ocean and this diffuses into the air because water can only hold small amounts of O2.

  The ocean provides 50% of atmosphere O2.   Gases
  The most important are O, CO2 and N.   Dissolved O2 = aerobic (use O2) and   none= anaerobic...  used for respiration and corrosion.    Oxygen  Turbulence increases the amount of O2 that can dissolve in water.   Dissolved O2 declines rapidly as depth increases...why??   Zones  At the depth where photosynthesis=rate of respiration its the compensation depth.   

  At the surface as O2 is used, its replaced quickly by photosynthesis and as it deepens, respiration becomes greater than photosynthesis.
  Light  Used for photosynthesis by plants with chlorophyll.   Much is reflected back to atmosphere and as wave action increases, more is reflected.  Light  Lots are absorbed by water but 65% of all light is absorbed within the 1st meter and only 1% gets to 100m.   Light Absorption  Certain wave lengths are absorbed..blue goes far down and this is vital to photosynthesis as most autotrophs use red and blue light. 
  

Zones  The sunlit area is the photic zone where 70% of worlds photosynthesis.   

Lower area (not sunlit) is the aphotic zone =90% of the ocean      Photic zone ranges from 1m in estuaries to 100m in open ocean and depends on turbidity.     

Turbidity increases along the coast as suspended solids increase.  

 This causes a shift of balance because where blue is the predominant absorbed light in crystal clear water, suspended solids enable wavelengths of green to penetrate deeper than blue in coastal waters.     The highly productive water of the coast is greenish and estuaries are brownish.   The compensation depth is shallower in coastal waters and below this the autotrophs can't get enough light for photosynthesis to meet the energy requirements. 

    Salinity  Salinity is expressed as concentration of ions in a liter of water or # of grams of dissolved solids in 1000g of seawater.   Solvent  Water is a solvent for most substances especially salts.   The characteristics of seawater are due to the nature of pure water and the materials dissolved in it.     Solvent  The solids in seawater come from two sources, the chemical weathering of rocks washed to the sea by the rivers and the earth's interior through hydrothermal vents. 

  Seawater Composition
  Water...the wonderful stuff held together by hydrogen bonds which causes ice to melt at 0 instead of -90.   

It causes the absorption of lots of heat to melt ice and same to evaporate water...cooling.      

 Seawater Composition
  It allows water to hold heat...heat capacity and the amount of heat needed to change water temperatures help for cooling of the earth  Components of Sea Water  Major components of seawater vary slightly.

   Two processes add salts to the ocean--river discharge and water circulations through hydrothermal vents (hotsprings).  Components of Sea Water  All ocean water cycles through these vents every 8-12 million years.   These work together making seawater, with the springs adding and removing chemicals.   

  Salinity    Seawater 1000g samples have 34.7g of dissolved matter so salinity is expressed as 34.7 ppt (0/000) or 3.47 % .   The remaining 96.5% is pure water.                   

  Salinity    Today they can measure electrical conductivity in conjunction with temperature of water sample.. conductivity is proportional to salinity           

   Salinity   Also even though organisms may be exposed to changes in salinity...rivers rain etc, they don't have to deal with changes in ratios of the various ions dissolved in the seawater.. 

  Salinity  Although constant, the concentration can change with addition or removal of water.   Different in local areas depending on rate of evaporation/precipitation and volume of fresh water dumped.     Salinity  [red sea=40, Mediterranean=38 lack of rain fall and high evaporation. Black Sea=18 Baltic Sea=8..low evaporation and high runoff.]  

 Salinity  Body of Water Grams (per Liter)        Ounces(per Quart) Distilled                      0                       0   Baltic Sea                7.1                     0.2   Black Sea                                   18.2                                    0.6   The Oceans                                 35.4                        1.2   Red Sea                         40.5                                    1.4   Great Salt Lake             172                                    5.7   The Dead Sea     293                                     9.8        More Terms  Euryhaline=organism can tolerate large salinities and fluctuation.  Stenohaline can't tolerate large salinity changes.  Vertical change surface layer mixed..uniform beneath the halocine layer … large salinity changes above..The salinity changes with depth.    Link to aquariums    

 

Review Questions  Online

Review Answers for 1st Review

Review Even Answers (odd posted before quiz)

Mar sci ocean floor/tect/chem. Notes EVEN Ans.

2. Remotely-Operated Vehicles (ROVs) used for deep-sea work have the advantage of being _safer than are people-carrying vehicles.

4. A flat-topped seamount is called a: guyot

6If the ocean evaporated, Earth's most obvious feature would be:mid-ocean ridge

.8 The deepest places on Earth are: trench

10Transform faults are fractures along which lithospheric plates move: transversely—side to side

12Ice is_less--dense than water

14In addition to mixing in from the air, oxygen enters seawater: Photosynthesis

16The average salinity of the world's oceans is about  (%o = parts per thousand) 35ppt

18. In iron deficient regions, adding iron to the oceans might reduce global warming by: increasing photosynthesis and using up co2

20.  What is the use of RADAR. LORAN, and GPS?navigation

22.  What types of reefs form around islands?fringing,barrier, atolls

24.  How was the sea level different 15,000 years ago? Lower  Why?Last ice age

26.  What evidence led to the acceptance of the theory of plate tectonics/sea-floor spreading?magnetic/cores/sight

28.  What is a hydrothermal vent? Hot water returning to ocean floor Of what importance are they?salts

30.  What is compensation depth?photo=resp

32.How does hydrogen bonding increase waters ability to moderate ocean temperature?energy must break bonds before temperature changes

 

Mar sci ocean floor/tect/chem. ODD ans

1. The crust under a continental shelf is com­posed of:granite

3. Continental shelves are primarily shaped when: sea level rises

5 A continental rise is made of sediment prima­rily from:run-fall off from the c/s

7. The superheated water associated with hydro­thermal vents is moved by:convection

9Submarine canyons are most often found on: continental shelf

11Hydrogen bonds are:weak

13Which atom(s) in a water molecule usually have a slight positive charge? H

15The major pH-buffering agents in the ocean are:carbonates

17 Is   nitrogen is present in a higher percentage than oxygen or carbon dioxide yes

19.  How is longititude and latitude measured? degrees

21.  Describe/name the features of the ocean floor?

23.  Why do trenches form?subduction zones

25.  What force moves the plates?convection currents

27. What is a hot spot? Magna burns through plates

29.  The most important physical factor limiting the distribution of ocean life is temperature

31. What are the sources of salts in the sea?river run-off---hydro vents