BCJS+1.4

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=Chapter 1.4=

Vocabulary:

 * Ocean Ridge:** the longest chain of mountains in the world
 * Sea-floor Spreading:** the process that continually adds new material to the ocean floor.
 * Deep-ocean Trenches:** the place where oceanic crust bends downward
 * Subduction:** the process where the ocean floor sinks beneath a deep-ocean trench and back into the Mantle

Sea-Floor Spreading

 * **Mapping the Ocean Ridge**
 * East Pacific is the longest chain of mountains in the world
 * Scientists map ridge with sonar
 * **Evidence for Sea-Floor Spreading**
 * Harry Hess examined mid-ocean ridge
 * The continents **DO** move
 * The ocean floor moves like conveyer belt, creating new rock and swallowing the old
 * Process is called sea-floor spreading
 * **Evidence From Molten Matieral**
 * Alvin's crew found weird shaped rocks in mid-ocean ridge
 * **Evidence From Magnetic Stripes**
 * Magnectic poles reversed lots of times
 * Rock have same magnetic charge if cooled at the same time
 * **Evidence From Drilling Samples**
 * Scientists found that the farther the samples were taken from MOR(mid-ocean ridge), the older it is
 * **Subduction at Deep Ocean Trench**
 * **Subduction and the Earth's Ocean**
 * **Subduction in the Pacific**
 * Pacific Ocean is **SHRINKING**! because of too many trenches
 * Mid-ocean ridge cannot produce how many rock that has already been taken
 * **Subduction in the Atlantic**
 * Atlantic Ocean is expanding, because there aren't enough trenches to take up too much rock
 * Atlantic's oceanic crust pushes the continental crust