Sea Level Change Flashcards
Eustatic
Change in volume of water in the sea or change of ocean basin
Global effects
Isostatic
Vertical movements of land relative to the sea
Local effects
Last 10.000 years and sea level change
Last glacial period water was stored in ice so low sea level than present
Last glacial maximum, 21.000 years ago sea level was 130 m lower than present
Since 1930 sea levels have been rising
Climate change as a cause
Global warming - 1.08 degree increase between 1900 and 2016
Result of combustion deforestation and greenhouse gases
How do greenhouse gases cause global warming
Absorb outgoing long wave radiation so less is lost to space
Conc increases more energy trapped and planet warms up
What is. Current global sea level rise and prediction for 2100
2 mm a year
9-16 mm a year by 2100
6 basic impacts of sea level change
More frequent storms More frequent and severe coastal flooding Submergence of low lying islands Changes in the coastline Contamination water sources and farmland Increased coastal erosion
Landforms at emergence coastlines
Raised beaches
Wave cut platforms
Relict cliffs
Landforms at submergence coastlines
Fjords
Dias
Dalmatian coastlines
What is a fjord
Drowned glacial Valley - typical U shape
relatively straight and narrow
very steep side
shallow mouth
What is a ria
Rias form where river valleys are partially submerged due to SLR
gentle and Long cross profile
Wide and deep mouth
What is a dalamation coastline
Where Valleys lie parallel to the coast and increase sea level Rise flood the valleys leaving islands parallel to the coastline
Example of short and episodic change and temporal scale and long and gradual
Storm over the last few hours
tectonic uplift over thousands of years
Formation of raised beaches
When the fall in sealevel leaves beaches above the high tide mark And over time beach sediment becomes vegiatated and develops into soil
