Author Question: Oceanic Ridge A has slow spreading rates of 2-5 cm/yr. Oceanic Ridge B has intermediate spreading ... (Read 120 times)

RRMR · **on:** Jul 15, 2018

Oceanic Ridge A has slow spreading rates of 2-5 cm/yr. Oceanic Ridge B has intermediate spreading rates of 6-9 cm/yr. Oceanic Ridge C has fast spreading rates of 10-11 cm/yr.

Compare and contrast the topography and structure that would be present at all three spreading centers.
What will be an ideal response?

Question 2

Compare seamounts and guyots. How do the two features differ?

What will be an ideal response?

daiying98 · **Reply #1 on:** Jul 15, 2018

Answer to Question 1

Answer: Slow-spreading centers like Ridge A will have prominent rift valleys and rugged topography. Intermediate spreading centers like Ridge B will have shallower rift valleys and more subdued topography. Fast-spreading centers will generate rises rather than ridges, with more gradual profiles and less rugged terrain.

Answer to Question 2

Answer: Both are submarine volcanoes growing upwards from the ocean floor above an elevated ocean ridge or hot spot. However, most seamounts do not have a long enough eruptive history to emerge from the ocean (though some can form volcanic islands). Guyots were volcanic islands that were carried away from the location of their formation, subsiding as they move away from that location, and that have been eroded down by wave action. Guyots generally have flat tops.