Sea Level Change Aims To understand the factors

Sea Level Change Aims: To understand the factors which cause sea levels to rise and fall. To know about the last Ice Age and isostatic adjustment. To understand how emergent and submergent features form.

Specification

Define the key terms • Use the textbook. • Relic cliff/coastline: cliff/coastline Ancient cliff line/coastline which is exposed when sea level drops/falls(Eustatic fall)

Sea levels change on a day to day basis • • Sea levels change on a day to day basis because of: High and low tides alter the local sea level every few hours Atmospheric air pressure has an influence on sea level—low air pressure causes a slight rise in sea level Winds can ‘push’ water towards a coast, and wave height varies from day to day Weather and climate has an influence on sea level height as mentioned on the previous page. Low pressure is caused by warm air rising and this lifts the sea level slightly.

Eustatic and Isostatic changes & Emergent and Submergent landforms

Glaciation and its link with sea level rise

Last Glacial Maximum (LGM)

Eustatic and isostatic changes during the last Ice Age

Isostatic Adjustment Scotland is rebounding upward in some Places by 1. 5 mm per yr England Wales are subsiding at up to 1 mm per yr. Great Britain is slowly pivoting upward in the north and downward in the south. Sea levels are slowly rising therefore isostatic adjustment compounds the effect in the south and cancels it out in the north.

Emergent Features

Emergent Features

Submergent Features

Barrier Island • Formation – – – Coastal sand dune attach to the shoreline Sea rise which floods the land behind the dune forming a lagoon Dunes are not eroded and become islands Sea level continues to rise and dune system moves landward.