Chapter 18 Extra Credit                 (6pts.)

 

1.    During the Challenger expedition, a single depth reading sometimes took an entire _______________.

 

2.    The most efficient method of obtaining a record of the ocean's history is by ___________ the ocean's floor.

 

3.    The seafloor can be directly observed by using supersensitive television cameras placed in _________________.

 

4.    In general, a broad continental shelf indicates that the continental margins are ___________.

 

5.    The two major regions of the ocean floor are continental margins and ___________.

 

6.    The upper parts of submarine canyons may have been formed by _____________ during the ice age.

 

7.    Landslides which run down continental slopes are called ________________.

 

8.    Gigantic gullies which cut through the continental slopes are called _____________.

 

9.    The gently sloping region between the continental slope and the ocean basin is the ______________.

 

10.                       Abyssal plains are composed of __________________.

 

11.                       Small, rolling hills that occur between abyssal plains and oceanic ridge systems are _______________.

 

12.                       Long, narrow, steep-sided troughs that parallel either continental margins or chains of volcanic islands are __________________.

 

13.                       Great underwater mountain ranges which cross every ocean are called _____________.

 

14.                       Sediments made from microscopic shells are called ______________.

 

15.                       The speed at which clays settle to the bottom of the ocean surface depends upon the ____________ of their particles.

 

16.                       Deposits which settle to the bottom of the ocean when an iceberg melts are called ________________.