Mid-ocean ridges (MORs),which are the sites of new oceanic crust formation,are linear mountain chains that run along divergent plate boundaries.Why does a MOR sit up higher than the surrounding oceanic crust?
A)Hot materials are less dense and shrink;thus,the new crust will sit higher than the surrounding crust.
B)As the hot magma exits the MOR,it shoots up higher than the surrounding crust.
C)Hot materials are less dense and expand;thus,the new crust will sit higher than the surrounding crust.
D)Hot,geothermal waters cause the new crust to expand and sit higher than the surrounding crust.

Question

Quizplus · Accepted Answer

Hot materials are less dense and expand, causing the new crust to sit higher than the surrounding crust. As magma rises to the surface at the MOR, it cools and solidifies to form new oceanic crust. The hot materials that form this new crust are less dense than the surrounding, cooler oceanic crust, causing it to expand and sit higher above the seafloor. This results in a linear mountain range along the divergent plate boundary known as the mid-ocean ridge.

Mid-Ocean Ridges (MORs),which Are the Sites of New Oceanic Crust