Divergent Plate Margins

Question 1

What plate margins occur at divergent plate boundaries?

Answer 1

• Constructive plate margins

Question 2

Outline what occurs at constructive plate margins

Answer 2

• Plates move away from each other
• Rising convection currents push bottom of lithosphere, lifting it and floating laterally beneath
• Lateral flows cause asthenosphere to be dragged in direction of flow
• Overlying plate is stretched thin, breaks and pulls apart
• Pressure released on mantle below, causing it to melt and new magma flow in crack
• Magma solidifies and process repeated

Question 3

What tectonic features are formed at divergent plate boundaries?

Answer 3

• Mid ocean ridges (e.g. Glapagos)

- Rift valleys (e.g. East African Rift Valley)

Question 4

What hazards occur at divergent plate boundaries?

Answer 4

• Shield volcanoes

- Gentle earthquakes