Climate Change Landforms Flashcards
Emergent coasts
Where the coasts are rising relative to sea level, possibly due to tectonic uplift
Submergent coasts
Where the coasts are decreasing/sinking relative to sea level
Sea level rise 1965-2090
1965-1993: 1.8mm/year increase
1993-2005: 3.1mm/year increase
2005-2090: 3.7-8mm/year increase (estimated)
Reasons for sea level rise
- Melting ice caps/glaciers due to global warming
- Thermal expansion
- Tectonic activity
- Post glacial rebound/isostatic adjustment (seesaw effect)
Eustatic change
Global sea level change
Isostatic change
Local sea level change
Ria
A river valleys that have been flooded due to rising sea levels. An example of a ria is Narragansett Bay in Rhode Island, USA
Fjord
A long, steep stretches of land that has been carved out by a glacier over thousand of years. They become flooded due to sea level rise. (e.g Sognefjord, Norway)
Raised beaches/Marine terraces
Cliffs that have survived on their own following destructive processes
Relict cliffs/Fossil cliffs/Abandoned cliffs
Areas of flat, elevated land, above the sea level, that are not reachable by waves. They are formed due to either a drop in sea levels, or a raise in the land that means that this area of land that was previously covered by the ocean is now unreachable at high tide. (Examples of raised beaches include Alexander Bay in South Africa and Ballyhillin Beach in the Republic of Ireland
What causes eustatic change?
Eustatic global change is caused by melting ice sheets (on land) and glaciers, in addition to thermal expansion, as ice that is already in the sea will not cause sea levels to rise when it melts. Eustatic change happens when ice melts following an ice age, as during an ice age, much of the precipitation is snow and therefore joins the ice on the land. Thermal contraction also occurs in an ice age, causing the sea levels to decrease
What causes isostatic change?
Isostatic local change can be caused by post glacial rebound. It can also be caused when weight is added to one side of the land, such as building developments. Tectonic activity can also result in isostatic change
Emergent landforms
Rias, fjords, shingle beaches
Submergent landforms
Raised beaches, relict cliffs