Divergent Plate Margins Flashcards Preview

Eduqas A Level Geography - Tectonic Hazards > Divergent Plate Margins > Flashcards

Flashcards in Divergent Plate Margins Deck (4)
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1
Q

What plate margins occur at divergent plate boundaries?

A
  • Constructive plate margins
2
Q

Outline what occurs at constructive plate margins

A
  • 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
3
Q

What tectonic features are formed at divergent plate boundaries?

A
  • Mid ocean ridges (e.g. Glapagos)

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

4
Q

What hazards occur at divergent plate boundaries?

A
  • Shield volcanoes

- Gentle earthquakes