Coastal landscape development and sea level change

Question 1

What is Eustatic change?

Answer 1

A global change in sea level resulting from an actual fall or rise in the level of the sea itself.

Question 2

What is Isostatic change?

Answer 2

Local changes in sea level resulting from the land rising or falling relative to the sea

Question 3

What is an example of eustatic change?

Answer 3

Climate gets colder - marking the onset of a new glacial period
More precipitation falls as snow - turns into glacial ice which acts as a store for water
Hydrological cycle slows down as water cycled from the sea to the land, does not return to the sea
Subsequently, sea levels fall

Question 4

Following on from the example of eustatic change, how may isostatic change occur?

Answer 4

The weight of ice causes the land surface to sink. This affects only some coastlines and then to a varying degree

Question 5

What is a fjord?

Answer 5

Former glacial valley drowned by rising sea levels

Question 6

What are Rias?

Answer 6

Former river valley drowned by rising sea levels

Question 7

Explain the concept of Rias and Fjords, carrying on from the isostatic explanation?

Answer 7

Climate will get warmer
Ice masses on land begin to melt
This starts to replenish the main store and sea level will rise locally (isostatic)
This floods the lower parts of the land to produce submerging features such as rias and fjords

Question 8

How do raised beaches form?

Answer 8

As the ice is removed from land - land rises
If the rate at which the land uplifts is greater than the eustatic sea level rise, emergent features will form - raised beaches

Question 9

What is an example of a raised beach?

Answer 9

Isle of Arran, Scotland - isostatic sea level change causing the north to rise because ice sheets were thickest in northern Scotland

Question 10

What is an example of a Ria?

Answer 10

Kingsbridge Estuary in Devon

RIAS KISS ENORMOUS DOLPHINS

Question 11

What is the percentage of the ocean which actually experiences thermal expansion?

Answer 11

10% - however this is predicted to increase into the 90% of the ocean that doesn’t experience it as of yet

Question 12

What is a submerging feature of coastline?

Answer 12

Rias

Question 13

What is another submerging feature of a coastline that isn’t a Ria?

Answer 13

Fjords

Question 14

Where are Fjords famous in?

Answer 14

Finland and Norway

Question 15

What is a submerged coastline called?

Answer 15

Dalmation coasts

Question 16

What is a Dalmatian coast?

Answer 16

A submerged coastline which was once a series of valleys and ridges running parallel to the shoreline. As sea levels rise, only the tops of the ridges are visible (as islands).

Question 17

Where are Dalmatian coasts famous in?

Answer 17

Croatian coast in the Adriatic

DALMATIANS CUT CORNERS in the APPLE

Question 18

What is an emerging feature of a coastline?

Answer 18

Raised beaches

Question 19

How do Rias form?

Answer 19

The floodplain of a river will vanish beneath rising waters, on the edges of uplands only the middle - and upper-course valleys will be filled with sea waiter, leaving the higher land dry and producing Rias.

Question 20

How do Fjords form?

Answer 20

They have steep valley sides and are straight and narrow.
They are not deepest at the mouth, and have a shallower section at the end, known as the threshold
They are formed when the sea drowned the lower part of glacial valleys that were cut to a much lower sea level

Question 21

What is isostatic uplift?

Answer 21

It is a local and relative change in sea levels controlled by the crusts response to the movement of ice.

Question 22

How does isostatic uplift occur?

Answer 22

During an ice age, the weight of the ice on a landmasses causes it to sink. As the earth’s temperature begins to rise again the ice melts and the weight decreases causing the land to slowly rise back out of the sea.

Question 23

What is the ‘bounce back’ motion that takes place during isostatic uplift?

Answer 23

The localised change in sea level, relative to the land

Question 24

What is a raised beach?

Answer 24

A raised beach is an elevated area of a sloping ground, sitting above the present tide line. In the past this area was at sea level.

Question 25

What does relict define as?

Answer 25

Something that has survived - for example structure of minerals after destructive processes have taken place

Question 26

What are the impacts of sea level rise?

Answer 26

Warmer oceans will increase the severity of storms
The current will be affected through heating
Bangladesh will see a 1m rise in sea level - leading to 1/5 of the country being submerged and 30 million people displaced

Question 27

How has sea level changed since 1993?

Answer 27

It has doubled

Question 28

What is the total heat taken up by the oceans in the last century and a half?

Answer 28

1,000 times the annual energy use of the world’s population

Question 29

How many tonnes of ice has Antartica lost in the last 25 years?

Answer 29

3 trillion tonnes

Question 30

How many people live within 1m of sea level?

Answer 30

150 million

Question 31

What is the predicted sea level change for 2100?

Answer 31

1m

Question 32

What will happen if humans limit global warming to 1.5 degrees?

Answer 32

They will still rise by 52cm

Question 33

What will happen if humans limit global warming to 2 degrees?

Answer 33

Sea levels will rise by 63cm

Question 34

What will the 11cm difference of sea level between 1.5 and 2 degrees cost?

Answer 34

1.4 trillion dollars per year

Question 35

What are swash aligned beaches?

Answer 35

Produced where the waves break in line (parallel) with the coast.
Swash & backwash movements move material up and down the beach producing the aforementioned beach profile features.
Swash aligned beaches are smoothy curved, concave beaches.
The beach face is orientated parallel to the fronts of the dominant waves. Beaches which face the waves are termed swash aligned.

Question 36

What are drift aligned beaches?

Answer 36

Produced where waves break at an angle to the coast. The swash therefore occurs at an angle but the backwash runs perpendicular to the beach. As a result, material is transported along the beach via longshore drift.