MULTIPLE CHOICE

1. An oceanic-continental plate boundary is:

a. the same type as oceanic-oceanic
b. a convergent type
c. a divergent type
d. a and b
e. a and c
 

2. A geoid is:

a. a sphere
b. an ellipsoid
c. the true shape  of  the earth
d. a mathematical approximation of the shape of the earth
e. an estimate of the shape of the earth used for mapping
 

3. There are three layers of the earth that you want to map.  They are 300, 550, and 1200 km deep.  How would these layers be represented at a 1:1000 scale?

a.  0.03, 0.055, 0.12
b.  30, 55, 120
c.  3, 5.5, 12
d.  0.3, 0.55, 1.2
e.  none of the above
 

4. Two of the most recent areas of sea-floor topography discovered are the:

a. Pacific-Antarctic rise
b. Juan de Fuca ridge
c. Louisville seamount
d. a and b
e. a and c
 

5.  Corrections to radar pulses from satellites are made for:

a. ionospheric delays
b. atmospheric delays
c. tidal corrections
d. a and b
e. a, b, and c
 

6. A  ____ repetition rate of ______  is used to improve the signal to noise ratio, especially when the ocean surface is _________.

a. high, 1000 pulses per minute, calm
b. low, 1000 pulses per minute, calm
c. high, 1000 pulses per second, rough
d. low, 1000 pulses per second, rough
e. high, 1000 pulses per minute, rough
 

7. What are the units of gravity?

a. 9.8 ft/sec
b. 8.9 m/sec²
c. 9.8 m/sec
d. 9.8 ft/sec²
e. 9.8 m/sec²
 

8. As the sea floor ages it:

a. reflects cooling of the plates
b. becomes covered in sediments
c. reflects subsidence of the plates
d. a and b
e. a, b, and c
 

9. Spreading ridges on the ocean floor are characterized by:

a. transform patterns of ridges
b. orthogonal patterns of ridges
c. transform faults
d. a and b
e. b and c
 

10. Undersea volcanoes:

a. can be found by gravity maps if the volcanoes are 1000 m tall or more
b. only about ½ have been charted previously
c. can occur alone
d. can occur in chains
e. all of the above
 

11. Measuring the amplitude and width of a gravity low and relating this to echo soundings can be used to measure:

a. petroleum deposits
b. length of volcanic chains
c. height of volcanoes
d. thickness and elasticity of tectonic plates
e. all of the above

TRUE/FALSE

1. Oceanic-continental collisions can result in volcanic activity.

True  or  False
 

2.  Hawaii is  an example of an oceanic-continental convergence.

True  or  False
 

3.  The ocean surface has broad bumps and dips that mimic the topography of the ocean floor.

True  or  False
 

4.  Oceanic flow and sea floor depth are proportional to s1/ square root of age, but inversely proportional to square root of age according to cooling halfspace models.

True  or  False
 

5.   The actual surface of the ocean deviates from the shape of an ideal ellipsoid  by 100 miles.

True  or  False