Oceanography
Section 1 The Seafloor
A. _____________________—low areas of Earth filled with water
1. __________________________—gradually sloping end of a continent that extends under
the ocean
2. __________________________ extends from the outer edge of the continental shelf down
to the ocean floor
3. _______________________—flat seafloor areas from 4,000 m to 6,000 m below the
ocean surface
B. As _______________________ move, the ocean floor changes.
1. ________________________—new ocean floor is formed.
a. When ocean plates separate, hot ______________ from Earth’s interior forms new
ocean crust.
b. Process called ___________________________.
2. _________________—long, narrow, steep-sided depressions
a. Form at _________________________, where one crustal plate sinks beneath another
b. Example: ________________ Trench
C. Many ________________ resources can be found in the ocean.
1. Petroleum, natural gas, oil, phosphorite, limestone, sand, and gravel—examples of continental
shelf deposits
a. _______________________________—can be mined
b. ________________________—can occur in coastal areas where rivers enter oceans
2. Sulfur, iron, copper, zinc, and silver—examples of __________________________ deposits
a. Too difficult and __________________ to mine
b. __________________________—deposits that form from minerals dissolved in ocean
water.