Sea level change impacts coasts - long+short term

• what are two types of sea level change

  eustatic and isostatic
• what is eustatic sea level change

  global sea level change due to a change in the volume of water
• what causes eustatic change (x2)

  milankovitch cycles cause climate change

  -during a glacial period the water it locked as ice sheets on land which lowers sea level

  -after a glacial period the ice sheets melt so volume of eater increases.

  warmer climate causes thermal expansion as volume increases as particles spread
• how often are glacial periods

  every 90,000 years
• what is isostatic change


  A local rise or fall in sea level due to the land riding or falling
• what causes isostatic change (x4)


  -post glacial adjustment

  -accretion

  -subsidence

  -tectonics
• what are the two types of coastline caused by sea level change

  submergent and emergent
• what is a submergent coastline

  where land that was above sea level becomes inundated
• what are types of submergent coastline

  rias, fjords, dalmation coastlines
• What is a ria?


  a drowned river valley
• explain the physical characteristics of a ria

  v shaped valley
• what is an example of a ria

  Kingsbridge estuary, Devon
• what is a fjord

  a drowned glacial valley
• explain the physical characteristics of a fjord


  steep sided, U shaped valley

  straight and thin
• where can a fjord be found


  Norway
• what is a Dalmatian coastline

  when river valleys run parallel to the coastline, andbthey get flooded it leaves parallel islands exposed
• where can Dalmatian coastlines be found

  Croatia
• how does post glacial adjustment cause rising sea levels

  during ice age when glaciers form, this causes land to sink as heavy which causes sea levels to rise
• how does post glacial adjustment cause falling sea levels


  end of ice age and glaciers melt this causes land to rise so sea levels fall
• what is accretion


  accumulation of sediment
• how does accretion lead to changing sea levels


  at sink areas of the sediment cell, if there is net deposition, the land is built up which causes sea levels to fall
• how does subsidence cause sea level change

  due to deposition, heavy buildings etc, pressure on the land cause land to sink, thus sea levels to rise

  (eg)Odisha due to urbanisation and ports
• how does tectonics cause sea level rise

  -transgression causes sea levels to rise as high volcanism causes sea water to displace out of the ocean basin

  -regression does the opposite as water returns to ocean basin

  -when volcanism is low, molten rock cools more quickly as causes sea levels to fall