Oceanography exam 1
Most processes that affect the ocean's salinity occur?
at the oceans surface
How can we map the topography of the sea floor from satellites?
by very accurately measuring the elevation of the sea surface
Atolls are related to plate tectonics because?
Volcanoes created at hotspots and ridges subside as they are carried away from their point of origin
The components of the ocean water whose proportions are not accounted for by the weathering of surface rocks are called?
excess volatiles
the velocity of sound in water is?
faster than in air
Currently in more carbon dioxide moving from the atmosphere into the oceans, or from the oceans into the atmosphere
from the atmosphere to the oceans
The amount of gas that sea water can hold in solution will be?
greater in colder water
The speed of sound in water is ___ the speed of sound in air?
greater than
The deepest parts of the Pacific Basin are located
near the margins of South America, Japan, and the Marianas islands
Which is greater the average height of the continents or the average depth of the ocean?
the average depth of the ocean
We can determine salinity if we know?
the chlorinity of a water sample
Land bases evidence for plate tectonics can be seen in
the distribution of Glossopteris flora and fauna, evidence of ancient glaciations, the alignment of mountain ranges, and the correlation of similar rocks in now widely separated continents.
The ions presented in seawater alter the characteristics of pure water in the following ways EXCEPT
the ions cause cells placed in sea water to burst
IS it possible for two samples of water to have the same density at different combinations of temperature and salinity. True/False
true!
What is the name of the outermost solid layer of the Earth?
Lithosphere
About one quarter of the Earth's surface is between what two elevations?
+1000 to 0m
The average salinity of the world ocean is closest to what?
34 0/00
About what percent of the volume of the oceans is contained in the "deep zone" beneath the pycnocline?
80%
Roughly how fast do most lithospheric plates move?
About 3cm a year
A "mystery" in our understanding of plate tectonics has been, until recently, the nature of the power source capable of moving the plates and the continents embedded within them. Recent evidence indicates the power source to be
Convection currents with in Earth's mantle are moving the plates
Oceanic salinities are lower at the Equator because?
Equatorial regions are an area of rising air heavy rainfall
At a depth of 50 meter, a red object would probably look?
Gray or black
Where are the Earth's oldest rocks found?
In the cores of continents
Name of professor?
Mark Stewart
A turbidity current is?
None of the above.A turbidity current is a current of rapidly moving, sediment-laden water moving down a slope through water, or another fluid
Dissolved oxygen levels tend to be high near the ocean's surface, and carbon dioxide levels are lower near the surface. Why?
Photosynthesis uses carbon dioxide and releases oxygen
The property of water that accounts for the ability of liquid water to absorb heat and change only very little in temperature is called?
Specific heat or heat capacity
Residence time is?
The average length of time an element spends in the ocean
Which of the following statements best describes the conservative constituents of seawater?
The concentrations of conservative constituents change very slowly in the open ocean
The most pronounced thermoclines exist in?
The tropics
What do paleomagnetism, seafloor spreading, Pangea, benioff zones, transform faults, fracture zones, seamount chains and Pacific hotspots all have in common?
They are all involved with plate tectonics
What is the approximate mixing time of the world ocean?
about 1,600 years
The wavelengths of light that penetrate deepest into the ocean are?
blue and violet
The temp of most of the world ocean is the?
deep and bottom waters
Why did N. American geologists reject Wegener's theory of continental drift?
he did not have a plausible explanation for how the continents moved
Karl Popper stated the to be considered a valid scientific theory, a theory
must be capable of being found to be false (tested)
The Bronze Age in the eastern Mediterranean was supported by the large copper deposits of the Troodos Massif on the island of Cyprus. These deposits are contained in a/an
ophiolite in a convergent boundary
Analysis of plate motion suggests that
part of California west of the San Andreas Fault is moving northward
The widest continental shelves are associated with _____ margins
passive
The trailing edge of a continent on a moving crustal plate is most likely to exhibit?
passive continental margins
Ocean depths are routinely determined by?
sending ships through the water and determining the time required for it to return to the ship
The ocean's deep sound channel (SOFAR layer) is characterized as a zone in which?
sound is horizontally concentrated rather than diffused as it moves through the water, acoustical energy losses are relatively small sound waves travel great horizontal distances and sound velocity is at a minimum.
In 1929, transatlantic telephone and telegraph cables on the continental slope in the north Atlantic near Newfoundland broke sequentially, from close to the coast first, to farther from the coast last, after an earthquake. The cables were probably broken by?
turbidity currents
Active sonars differ from passive sonar in that active sonar?
use sound to probe as well as listen
Why is it harder to get sea water to freeze than freshwater
when you cool sea water, it gets more dense and sinks
