Sea Level Change and Associated Landforms Flashcards
Adaptation vs mitigation
Mitigation= reducing the severity/ impact of something so that adaptation isn’t necessary
Adaptation= making adjustments to live with the problems being faced
…change is where the sea level rises or falls on a global scale (refers to global sea level change)
Eustatic
…change is the local change in sea level as a result of the land rising or falling relative to the sea
Isostaic
2 ways to describe sea level change
Eustatic
Isostatic
Eustatic sea level change meaning
The rise or fall of sea level on a global sea level (global sea level change)
Isostatic sea level change meaning
Local changes in sea level as a result of the land rising or falling relative to the sea level
Describe stage 1 in the cycle of sea level change
During the glacial period, the climate got colder leading to more precipitation falling in the form of snow and ice (instead of rain which would then just go back into the sea) which increased the amount of ice and glacial ice there was covering the earth. At the same time, the cooling of the earth led to the hydrological cycle slowing down so any precipitation that was in the form of rain/ water was returned to the sea much more slowly and together with less water entering the sea and more water being stored in the form of ice/ glacial ice instead of in the sea the sea level fell (Eustatic sea level fall)
Describe stage 2 in the cycle of sea level change
As a result of more ice and glacial ice forming on top of the land as the climate got colder, the weight of this ice on the land caused the land surface to sink (be compressed) resulting in the sea level rising in relation to the sea (Isostatic sea level rise but also referred to as Isostatic subsidence)
Describe stage 3 in the cycle of sea level change
During the interglacial period the climate got warmer again so lots of the ice and glacial ice melted meaning more water flowed back into the sea resulting in the sea level rising (Eustatic sea level rise)
Describe stage 4 in the cycle of sea level change
As the climate got warmer and lots of the ice melted it meant that the weight of the heavy ice was removed from the land causing the land to rise back up to its original position (rebound/ readjust) resulting in the sea level falling relative to the land (Isostatic sea level fall but commonly referred to as Isostatic rebound/ readjustment)
Describe 4 stages in cycle of sea level change
Stage 1: During the glacial period the climate got colder causing more precipitation to fall in the form of ice and snow instead of water so less water was entering the sea but instead was being stored in ice/ glacial ice on top of the land (the amount of ice and glacial ice covering the land surface increases). The colder climate also causes the hydrological cycle to slow down so any precipitation that does fall as rain takes longer to flow into the sea. Together these factors mean that less water is entering the sea so the sea level falls (Eustatic sea level fall)
Stage 2: As a result of more ice and glacial ice forming on the land the surface of the land sinks (is compressed) due to the weight of the ice causing the sea level to rise relative to the sea (Isostatic sea level rise)
Stage 3: During the interglacial period the climate gets warmer causing lots of the ice and glacial ice to melt so the water that was stored in it flows back into the sea and more water entering the sea means the sea level rises (Eustatic sea level rise)
Stage 4: As the ice/ glacial ice melts this causes the land to rise up (readjust/ rebound) back to its original position as the heavy weight of the ice that was compressing it has been removed. This leads to the sea level falling relative to the land (Isostatic sea level fall but more commonly referred to as Isostatic rebound/ readjustment)
When the sea level rises the coastline is drowned leading to..features being formed e.g Dalmatian coasts, rias and fjords
Submergent
When the sea level falls/ land rises the coastline is left high above sea level leading to …features being formed e,g raised beaches, marine platforms and relict coastlines
Emergent
3 key submergent features of coastline (formed when sea level rises and coastline is drowned)
Dalmatian coast
Ria
Fjord
3 key emergent features of coastline (formed when sea level falls so land is left high above sea level)
Raised beach
Marine platform
Relict coastlines (coastlines that are no longer reached by the high tide)
Dalmatian coasts are named after Dalmatia (a coastal region) in…
Croatia
(So hence the name the main place Dalmatian coasts are found is Croatia as they were named after the place)
Describe formation of Dalmation coasts
Dalmatian coasts are formed when mountains run parallel to the coastline and the river valleys/ low lying land between the mountains get flooded. This leads to the mountain ranges (running parallel to the coastline) becoming islands
Dalmatian coasts are found where…run parallel to the coastline and the river valley between the…becomes flooded so the…become islands
(Same word)
Mountains
…coasts are found in Croatia and Chile where mountains run parallel to the coast and are formed when the river valleys and low lying land running parallel to the sea that are between the mountains become flooded so that the mountains/ higher land are left as islands
Dalmatian
Rias are formed when rising sea level floods the ..and floodplain so that only the higher…sides remain visible on land whilst the lower sides are covered in water. This leaves behind sheltered, winding inlets that are deepest at the mouth and have a dendritic pattern
(Rias are drowned river valleys with a dendritic pattern)
River valley
Valley
Rias can be described as …as from overhead they have a branched shape
Dendritic
Rias are drowned…valleys but fjords are drowned…valleys
River
Glacial
Rias are…, … inlets with…shorelines that are deepest at the…and have a…pattern
Sheltered
Winding
Irregular
Mouth
Dendritic
A fjord is a drowned …valley found in Norway and New Zealand that are straight, narrow and steep sided U shaped valleys and aren’t deepest at the mouth due to the…
Glacial
Threshold
Mitigation meaning
To reduce the severity of something so that adaptation isn’t necessary
Adaptation meaning
Making adjustments to live with the problems being faced
What stage in the cycle of sea level change leads to submergent features being formed e.g Dalmatian coasts, rias and fjords
Stage 3
(Eustatic sea level rise during glacial period (usually at end of the interglacial period as that’s when the most melting has occurred so the sea level has risen the most and the coastline is more likely to get flooded)
True or false, when rias are formed only the river valley is flooded
False
The surrounding floodplains are also flooded
Describe formation of fjords
During the glacial period, the climate got colder which led to glaciers being formed. The glaciers slowly advanced down v shaped valleys and eroded the sides and bottom in the process to form a U shaped valley.
As the glacier slowly retreated it transported sediment with it which it deposited just before reaching the sea to create a threshold.
During the interglacial period as the climate got warmer the glacier then melted leaving behind a steep sided, narrow and U- shaped valley
A marine platform is a former…that was formed when the sea level was higher but is now fully exposed 100% of the time and isn’t reached by high tide
Wave cut platform
A raised beach is a beach/ platform formed by…when the sea level was higher but is now fully exposed 100% of the time and isn’t reached by high tide
Deposition
Both marine platforms and raised beaches were formed when the sea level was higher but are now fully exposed 100% of the time and aren’t reached by high tide.
So what’s the difference
Marine platform= former wave cut platform (erosional feature)
Raised beach= former beach (depositional feature)
Describe the formation of a marine platform
A marine platform is an example of an emergent feature formed by processes of erosion that lead to a wave cut platform being formed. During the glacial period the climate gets colder so more precipitation falls in the form of ice and snow instead of water. The hydrological cycle also slows meaning any precipitation that does fall as water enters the sea much more slowly leading to Eustatic sea level fall. This causes the old wave cut platform to become exposed as it is no longer in the active zone of the coastline (no longer reached by the sea including by high tide).
The wave cut platform can also become exposed above the water due to Isostatic rebound where during the interglacial period as the climate gets warmer and the ice melts, there is no longer the weight of the ice on top of the land compressing it so it slowly rises back up (readjusts) leading to the formation of a marine cut platform as the land is now above the water so the wave cut platform isn’t reached by high tide
