3.Coastal Risks

Question 1

Tectonic change

Answer 1

• causes land to either rise or sink at the boundaries where tectonic plates meet
• sudden change in movement of a plate can lead to rise of fall in seabed, change is seal level
• earthquakes out at sea can trigger tsunami, causing devastating effects

Question 2

Isostatic change

Answer 2

• refers to the level of the land, which is also influenced by ice ages
• during ice age, weight of ice forces land to sink
• when ice age has finished, melting ice caused land to rebound back up

Question 3

Eustatic change

Answer 3

• rising and falling of sea levels, influenced by ice ages
• water stores in form of ice when world is experiencing an ice age, causing sea level to fall
• as world moves out for an ice age, ice melts cauing sea levels to rise again

Question 4

Submergent Coastlines

Answer 4

on coastlines that were not affected by glacial ice cover, sea level rise has created submergent (drowned) coastlines

Question 5

emergent coastlines

Answer 5

a stretch along the coast that has been exposed by the sea by a relative fall in sea levels by either isostatic or eustatic change

Question 6

Rising sea levels

Answer 6

• from 1901 to 2010 average sea levels have increased by 0.19m
• some of the contributing factors are melting of glaciers and ice sheets
• higher sea levels could cause higher tides which would lead to more coastal flooding and removing material from beaches so cliffs less protected

Question 7

Hard engineering

Answer 7

• hard engineering in coastline can disrupt sediment cells meaning by disrupting one bit of coast, areas further along coast may be starved of sediment supply, resulting in destruction of beaches

Question 8

Subaerial processes

Answer 8

Sub-aerial process are land-based processes which alter the shape of the coastline. These are a combination of weathering and mass movement.