Emergent and Submergent coasts

Question 1

what are Rias

Answer 1

they are submerged river valleys, formed as sea level rises, however the top part of the river course may stay exposed

Question 2

what are Fjords

Answer 2

they are submerged glacial valleys. they have step, almost cliff like valley’s sides and the water is uniformly deep (often reaching over 1000 deep)
for example the Sogne Fjord in Norway is nearly 200km long

Question 3

what are shingle beaches

Answer 3

when sea level falls as the volume of land based ice grows, large areas of ‘new’ land emerge from the sea

Question 4

what happens in a transgression

Answer 4

• sea level rises
• eustatic change
• leading to existing landforms being submerged

Question 5

what happens in regression

Answer 5

• rise in land level
• isostatic change
• emergent landforms occur

Question 6

when as the world sea level at the lowest point

Answer 6

16000

Question 7

what has happened to northern Scotland

Answer 7

has sprung up, due to the weight and pressure that the ice sheets were exerting on them being realeased

Question 8

what has happen to the south of England

Answer 8

relative drop in sea level (key to remember that over 18,000 years ago you called walk across the English channel to France

Question 9

how often, do we experience a solar maximum

Answer 9

every 11 years or so

Question 10

what are the 3 emergent coastal features

Answer 10

• raised beach - used to be a normal beach
• marine terrace - similar to raised beaches much higher up, could of been a short platform before sea level rose
• a relict cliff a cliff however know it is far more stable as erosion only occurs from weathering and mass movement

Question 11

what process, could modify a relic cliff

Answer 11

• weathering
• mass movement

Question 12

what process, could modify a marine terrace

Answer 12

• will no longer experience wave erosion
• could experience weathering
• possible mass movement process may effect it.

Question 13

what process, could modify a raised beach

Answer 13

• becomes covered in vegetation
• weathering may effect it
• mass movement process may effect it

Question 14

name the 3 submergent coastal features

Answer 14

• rias
• fjords
• shingle beaches

Question 15

state 3 reasons why rias form

Answer 15

• tributaries fill with sediment causing some of the water to overspill
• costal process, like deposition and erosion
• current eustatic rise, continues to flood them

Question 16

state 3 reasons why shingle beaches form

Answer 16

• due to large quantities of sediment being deposited by from glaciers that melted in the Flandrian transgression
• coastal process, have pushed sediment onto the coastline
• eustatic rise in sea level post glaciation, carries sediment on shore, causing these large shingle beaches

Question 17

state 3 reasons why fjords form

Answer 17

• large glacial valleys become flooded, when the glaciers melted at the end of the glacial periods
• weathering due to current eustatic change
• hanging valleys join fjords at right angle and pre existing spurs create by action of river become truncated

Question 18

what is eustatic change (sea)

Answer 18

a global change in sea level resulting from an actual fall or rise in the level of the sea

Question 19

what is a isostatic change (land)

Answer 19

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

Question 20

emergent coastline

Answer 20

a decrease in sea level

Question 21

submergent coastline

Answer 21

a increase in sea level

Question 22

what is a marine terrace

Answer 22

similar to a raised beach it could of been a shore platform, before we saw a decrease in sea level

Question 23

describe the global eustatic changes in sea level

Answer 23

• shows sea level change, over last 20,000 years
• 18,000 years ago we had the world lowest sea level.
• 8000 years ago, the sea level started to rise slowly
• melting of ice, caused rapid sediment build up, forming beaches, and other depositional landforms

Question 24

describe the isostatic changes around the UK

Answer 24

• northern Scotland, has sprung up, due to being released from the pressure that the ice sheets had, that caused it to lower
• relative drop in sea level
• 18,000 years ago, one could walk to France.

Question 25

how does volcanic activity, effect emergent and submergent coasts

Answer 25

changes in the composition of the atmosphere due to major volcanic eruptions, which reduce incident solar radiation

Question 26

what is a relict cliff

Answer 26

a cliff, which is no more stable, as erosion only occurs on it via the process of weathering and mass movement