EQ3

Question 1

what are the 2 types of sea level change

Answer 1

isostatic change
eustatic change

Question 2

what is isostatic change

Answer 2

a local rise or fall in land level

Question 3

what is eustatic change

Answer 3

a global rise or fall in sea level

Question 4

how is eustatic change impacted by glacial periods

Answer 4

In cold glacial periods, precipitation falls as snow, forming huge ice sheets that store water normally held by the ocean, as a result sea levels fall.

Question 5

how is eustatic change impacted when glacial periods end

Answer 5

At the end of a glacial periods temps rise, the ice sheets will melt and retreat the stored water then flows into the rivers/sea again – sea levels rise

Question 5

how is isostatic change impacted by glacial periods

Answer 5

During glacial periods the weight of the ice sheets makes the land sink, this is called isostatic subsidence.

Question 5

how is isostatic change impacted when glacial periods end

Answer 5

As the ice begins to melt at the end of a glacial period, the reduced weight of the ice causes the land to readjust and rise – isostatic recovery.

Question 6

TRUE OR FALSE isostatic changes are fast and eustatic changes are slow

Answer 6

FALSE
Eustatic changes occur relatively quickly whereas isostatic changes take much longer

Question 7

what are the landforms created by sea level changes

Answer 7

A fall in sea level exposes land previously covered by the sea creating an emergent coastline

A rise in sea level floods the coast and creates a submergent coastline

Question 8

what are the 3 factors that increase risk of coastal flooding

Answer 8

height of land
subsidence
storm surges

Question 9

what is most coastal flooding caused by

Answer 9

storm surges

Question 10

what is storm surges caused by

Answer 10

a short term change in sea level caused by low air pressure

Question 11

what causes a lower air pressure

Answer 11

A depression in the mid latitudes e.g the Uk
A tropical cyclone (hurricane, typhoon) in areas just north or south of the equator

Question 12

why does the pressure drop cause a rise in sea level

Answer 12

As air pressure drops, the weight of air pressing down on the sea surface drops, so the sea surface rises

Question 13

what makes the drop in air pressure worse for coastal flooding

Answer 13

Strong winds push waves on shore, so wave height increases

If it’s high/spring tide at the same time

coastal topography

Question 14

why does climate change mean increased flood risk?

Answer 14

more storms
more flooding

Question 15

does climate change mean more hurricanes/cyclones

Answer 15

It’s not clear whether climate change will mean more hurricanes (cyclones) but warmer ocean-surface temperatures and higher sea level are expected to make them more intense

Question 16

explain how climate change effects flooding

Answer 16

coastal flooding is affected by climate change as its likely to increase the risk due to sea levels rising due to melting glaciers, ice caps and thermal expansion

Question 17

TRUE or FALSE as sea levels rise storm surges grow in height

Answer 17

TRUE
As sea levels continue to rise, storm surges will become higher

Question 18

define adaptation

Answer 18

making changes to lessen the impacts of flooding

Question 19

examples of countries adapting to coastal flooding

Answer 19

building storm surge barriers
reinstating mangrove forests

Question 20

how do mangroves protect coastlines from coastal flooding

Answer 20

they stabilise coastlines against erosion providing protection and shelter against extreme weather events, they absorb and disperse tidal surges energy associated with these events.

Question 21

what two factors lead to some coastlines eroding faster than others

Answer 21

physical and human factors

Question 22

what are the physical factors that lead to some coastlines eroding faster than others

Answer 22

-Long wave fetch and large, destructive ocean waves
-Soft geology, especially unconsolidated sediment
-Cliffs with structural weakness such as seaward rock dip and faults
-Cliffs that are vulnerable to mass movement and weathering as well as marine erosion
-Strong longshore drift; eroded debris is quickly removed exposing the cliff base to further erosion

Question 23

what are the human factors that lead to some coastlines eroding faster than others

Answer 23

When a coastal sediment cell has been interfered with
Dredging
Management schemes

Question 24

how does the erosion rate vary

Answer 24

In time: with peaks of erosion occurring in some seasons, and with some years having a lot of recession and some very little.
Spatially: with some locations having much less erosion than others.

Question 25

what are the 5 factors that influence erosion rate

Answer 25

Wind – both direction and fetch
Subaerial processes
Tides
Seasons
Weather systems and occurrence of storms