Constructive Margins- Oceanic Ridges

Question 1

Length of oceanic ridges

Answer 1

They are the longest continuous uplifted features on the surface of the planet- total length of 60,000 km

Question 2

In some parts oceanic ridges..

Answer 2

Rise 3,000 m above the ocean floor

Question 3

Their precise form appears to be influenced by..

Answer 3

The rate at which they separate

Question 4

Slow rate oceanic ridges

Answer 4

• 10-15mm p/a
• Mid-Atlantic ridge
• Wide ridge axis 30-50km
• Deep (3000m) central Rift Valley with inward facing fault scarps

Question 5

Intermediate rate oceanic ridges

Answer 5

• 50-90 mm p/a
• Galapagos ridge (Pacific)
• Less well-marked Rift (50-200m deep) with a smoother outline

Question 6

Rapid rate oceanic ridges

Answer 6

• > 90mm p/a
• East Pacific rise
• Smooth crest and no rift