this question and email it to biovcc@Gmail.com
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
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 ago…probably
at least 3.4-3.5 billion years ago as the oldest fossils yet found
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.
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.
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.
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..
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.
were usually professional men in other fields, often physicians or explorers,
but generally were individuals not specifically employed to carry out natural
Notable among these are the explorations
of Humboldt and of James Cook, who made extensive voyages and observations of
the natural world.
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
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.
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
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
and aircraft has also greatly increased our ability to measure and study parts
of the marine environment that are difficult to observe in person.
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.
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
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
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!
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
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
value of that division where its meridian meets the equator.
location on Earth is described by two numbers--its latitude and its longitude.
a pilot or a ship's captain wants to specify position on a map, these are the
"coordinates" they would use.
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.
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.
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.)
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
and Longitude A
lines of longitude is also called a meridian, derived from the Latin, from
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.
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.
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.
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
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
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!).
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
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.
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.
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.
a built-in computer, these receivers then derive their own precise position on
the ground, within 10-50 meters. .
operates its own system, GLONASS, and European countries are planning a third
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 -
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
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.
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").
To the Oceans
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.
To the Oceans
necessary therefore, to examine the physical and chemical conditions of seawater
and aspects of its motion (oceanography) and look at the environment where the
To the Oceans
(Water) Cycle Introduction
To the Oceans Where
is all the Water? Introduction
To the Oceans
To the Oceans Ocean
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
major basins are the Pacific, Atlantic, Indian, Arctic, Southern ocean and the
boundaries are artificially defined.
To the Oceans
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
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.
To the Oceans
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.
To the Oceans
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.
To the Oceans
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.
gradually drops down to the 100-200m depth. Introduction
To the Oceans
of Continental Shelf
To the Oceans
slope begins where continental shelf plunges down.
As the steepness decreases, this zone is
called the continental rise. Introduction
To the Oceans
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.
refilled, flooding shelf and forming underwater canyons.
The rise slowed 3000 years ago and has
only risen 10m since.
To the Oceans
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
To the Oceans
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
To the Oceans
Formation Converge: one plate dives under another,
crumples and forms trenches...
To the Oceans
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
at speeds up to 17mph.
These currents may have been responsible for enlarging submarine canyons Introduction
To the Oceans Turbidity
are 8 major plates, up to 100 miles thick and move slowly.
know the direction and speed so can figure out what the continent was like
before it moved.
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.
PLATE TECTONICS ALFRED WEGENER
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
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.
Iceland;63.30 N 20.62 W;170 m elevation
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
1. apart new
material rise as magna /molten rock filling spaces (rifts form mid ocean
1965 research vessel
Eltanin did magnetic studies
1969 Glomar Challenger did
cores from Pacific-Antarctic ridge
1977 Project Famous used
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.
3. Lateral-sideswipe and cause earthquakes
volcanoes and deformations
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
Moves W/NW at approx. 5-10 cm per year
Currently being subducted beneath the N. American and Eurasian plates
Moves over stationary hot spot in
Earth’s mantle Hot
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.
rocks of the Big Island are approx. 0.7 million years old.
magma from within the Earth’s mantle pushes up the Earth’s crust resulting in
the formation of an undersea volcano.
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
Tectonics and Seismic Hazard
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
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.
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.
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
decreases density..ice= .92g/cm3 and is less dense so
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.
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.
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.
sunlit area is the photic zone where 70% of worlds
area (not sunlit) is the aphotic zone =90% of the
zone ranges from 1m in estuaries to 100m in open ocean and depends on 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
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.
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
Water...the wonderful stuff held
together by hydrogen bonds which causes ice to melt at 0 instead of -90.
causes the absorption of lots of heat to melt ice and same to evaporate
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 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..
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
Ounces(per Quart) Distilled
0.2 Black Sea
0.6 The Oceans
1.2 Red Sea
1.4 Great Salt Lake
5.7 The Dead Sea 293
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
Answers for 1st Review
Even Answers (odd posted before quiz)
sci ocean floor/tect/chem.
Notes EVEN Ans.
Remotely-Operated Vehicles (ROVs) used for deep-sea work have the advantage of
than are people-carrying
A flat-topped seamount is called a: guyot
the ocean evaporated, Earth's most obvious feature
The deepest places on Earth are: trench
faults are fractures along which lithospheric plates
move: transversely—side to side
is_less--dense than water
addition to mixing in from the air, oxygen enters
average salinity of the world's oceans is about (%o
= parts per thousand)
In iron deficient regions, adding iron to the
might reduce global warming by: increasing photosynthesis and using up
20. What is the use of RADAR. LORAN, and GPS?navigation
22. What types of reefs form around islands?fringing,barrier,
24. How was the sea level different 15,000
years ago? Lower
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
sci ocean floor/tect/chem.
The crust under a continental shelf is composed
Continental shelves are primarily shaped when:
sea level rises
A continental rise is made of sediment primarily
from:run-fall off from the
superheated water associated with hydrothermal vents is moved by:convection
canyons are most often found on: continental shelf
atom(s) in a water molecule usually have
a slight positive charge? H
major pH-buffering agents in the ocean are:carbonates
Is nitrogen is present in a higher
oxygen or carbon dioxide yes
19. How is longititude and latitude measured? degrees
21. Describe/name the features of the ocean
23. Why do trenches form?subduction
25. What force moves the plates?convection
What is a hot spot? Magna burns through plates
29. The most
important physical factor limiting the distribution of ocean life is
What are the sources of salts in the sea?river run-off---hydro vents