Coastal Landscape Development- Sea Level Change Flashcards
Eustatic Change
A global change in sea level from the rise and fall in sea level itself
2 Causes of Eustatic Change
Thermal expansion
Land ice melt
Isostatic Change
Local changes to sea level from land rising and falling relative to sea
2 Causes of Isostatic Change
Slow uplift of land after glacials
Subsidence after groundwater abstraction
Sea Level Sequence
Decrease in global temperature
Ice accumulates
Decrease in volume of water available to fill oceans
EUSTATIC FALL
Sea level partly moderated by ice forcing land mass down
ISOSTATIC CHANGE
Increased temperature, ice melts, increased sea levels
EUSTATIC CHANGE
Increased sea levels flood some coastlines- submergent land forms
Ice fully removed
ISOSTATIC REBOUND
Prolonged rebound- emergent land forms
Emergence
Rising coastline
Mainly due to isostatic rebound
Raised Beach
Decrease in sea level, beach above high tide mark
Sediment vegetated overtime, soil develops
Marine Platform
Wave cut platform, now raised above current level
Gently sloping in front of relict cliff
Relict Cliff
Above raised beaches, no longer eroded by the sea
Contains wave cut notches, arches, stacks
Slowly covered by vegetation
Gradually weathered
Submergence
Sinking coastline
Eustatic change
Rias
River valley partially submerged
Gentle, long cross profile
Fjords
Drowned glacial valleys
Steep sides
Very deep inland, shallow at threshold
Dalmatian Coasts
Valleys parallel to coast
Flooded, creating islands parallel to coastline
Negative impacts of climate change
Storms with increased frequency and intensity
Coastal flooding
Submergence of low lying islands
Contamination of water sources and farmland
Increased coastal erosion
Storms with increased frequency and intensity
Changes in ocean circulation and wind patterns
Damages ecosystems and settlements
Submergence of low lying islands
MALDIVES
Contamination of water sources and farmland
Saltwater enters freshwater lakes and rivers, damages ecosystems
Saltwater enters soils and damages crops
80,000m2 lost in Holderness each year
Increased coastal erosion
Road, rail at risk
Easington Gas Terminal at risk- 25% of UK gas
Positive impacts of climate change
Energy generation
Physical and mental health benefits
Trade links
Energy generation
Coastal regions generate 20% of UK energy
Tidal power: Swansea Bay Tidal Lagoon
Trade links
Ice melt opened up West Passage and Northern Sea Routes along Russia’s Arctic coastline
Increases international trade
Decreased fuel for ships- Japan to Holland fuel consumption reduced by 20%
Tectonic Change
Opening and closing of ocean basins
Larger = lower sea levels
Changes to Sea Level in Last 10,000 Years
Glacial until 12,000 years ago- water stored in ice sheets, lower sea levels than present
Temp increases, ice melts- rapid sea level rise
In last 4,000 years sea level has fluctuated around present value
