SEA LEVEL CHANGE

• by how muchc have avg sea levels risen since 1900?

  15cm
• what are the 2 main causes of sea level change?

  • eustatic change
  • Isostatic change
• what is eustatic change?

  When the sea level itself rises or falls
• what is isostatic change?

  when the land rises or falls , relative to the sea
• where does eustatic change occur?

  eustatic change is GLOBAL
• where does isostatic change occur?


  LOCALLY
• Describe eustatic change?

  • global
  • in glacial periods , precipitation falls as snow instead of rain and forms huge ice sheets that store water that is usually held in the oceans
  • thus sea levels fall
  • as temps rise at end of glacial period, ice sheets melt and retreat- and the stored water flows into rivers and sea levels RISE
• describe isostatic change?

  • occurs locally
  • during glacial periods the enormous weight of the ice sheets makes the land sink- ISOSTATIC SUBSIDENCE
  • as the ice melts at the end of glacial period , the reduced weight of the ice causes the land to READJUST and RISE - ISOSTATIC RECOVERY