Sea Level Changes

Question 1

State the 2 types of Sea Level Change.

Answer 1

-Isostatic
-Eustatic

Question 2

Define Eustatic Change.

Answer 2

A Sea Level Change caused by a Change in the Volume of Water or a Change in the Shape of Ocean Basins.

Question 3

State whether Eustatic Change is Local or Global.

Answer 3

Global.

Question 4

State the 3 Factors that influence Eustatic Change.

Answer 4

-Thermal Expansion
-Tectonic Movement
-Ice Sheet Melt

Question 5

Explain the Impact of Thermal Expansion on Eustatic Change.

Answer 5

As Ocean Temperatures increase, Water Expands which increases the Volume of Water in the Ocean.

Question 6

Explain the Impact of Tectonic Movement on Eustatic Change. (3)

Answer 6

-The Earth’s Crust is constantly changing Shape and therefore the Capacity of the Ocean Basin.
-Sea Floor Spreading increases the Volume of the Basin and so decreases Sea Level.
-Underwater Volcanism produces large Volumes of Material that Displace Sea Water, causing Sea Level to Rise.

Question 7

Explain the Impacts of Ice Sheet Melt on Eustatic Change.

Answer 7

Global Warming has increased Ocean and Atmospheric Temperatures causing Ice Sheets to Melt and hence Sea Levels have Risen.

Question 8

Define Isostatic Change.

Answer 8

Sea Level Change caused by Vertical Movements of the Land Relative to the Sea.

Question 9

State 4 Factors that influence Isostatic Change.

Answer 9

-Post-Glacial Adjustment
-Accretion
-Subsidence
-Tectonics

Question 10

Explain the Impacts of Post-Glacial Adjustment on Isostatic Change. (2)

Answer 10

-During Glaciation Periods, Heavy Ice Sheets Weight the Land down.
-Post-Glaciation the Ice Sheets Melt and Land Rebounds to a Higher Level causing Sea Level to Fall in Isostaic Rebound.

Question 11

Explain the Impact of Accretion on Isostatic Change.

Answer 11

Acccretion is where there is Net Deposition of Sediment causing Land to Fall realtive to the Sea Level.

Question 12

Explain the Impact of Subsidence on Isostatic Change.

Answer 12

Subsidence of Land is caused by Excess Groundwater Extraction such as the Drainage of Marshland.

Question 13

Explain the Impact of Tectonics on Isostatic Change.

Answer 13

Volcanism releases Lava and Ash causing Land to Rise Relative to Sea Level.

Question 14

State how many mm a Year Scotland is Rebounding since the last Ice Age.

Answer 14

1.5mm a Year.

Question 15

State how many mm a Year Cornwall is Sinking since the last Ice Age.

Answer 15

1.1mm a Year.

Question 16

Since the last Glacial Maximum 21,000 yrs Ago, How has Sea Level Changed? (3)

Answer 16

-Sea Level has Increased by 130m.
-Sea Level has Fluctuated at its Current Level for the last 4000yrs.
-Since 1930’s Sea Level has started to Rise again.

Question 17

State the Global Average Sea Rise per Year.

Answer 17

2mm.

Question 18

State the 2 types of Coastal Landforms created by Sea Level Changes.

Answer 18

-Emergent
-Submergent

Question 19

Define Emergent Landforms.

Answer 19

Landforms that arise from Sea Level Falling and Isostatic Rebound.

Question 20

State 2 types of Emergent Landforms.

Answer 20

-Raised Beaches
-Fossil Cliffs

Question 21

Explain the Formation and Characteristics of a Raised Beach. (4)

Answer 21

-Realtive Sea-Level Rise Primarily due to Isostatic Rebound.
-Beaches are raised above the High Tide Mark.
-They Experience Succession by Vegetation due to no more Erosion occuring from the Sea.
-Raised Beaches also expose Marine Platforms and Erosional Landforms like Caves etc.

Question 22

Cliffs behind Raised Beaches can also be called…?

Answer 22

Relict Cliffs.

Question 23

Explain the Formation of a Fossil Cliff. (4)

Answer 23

-Isostatic Rebound or Eustatic Change causes Sea Level to rise.
-This exposes the Retreated Wave-Cut Platforms/Notches.
-Erosion stops as the Cliff is too High above Sea Level.
-Cliff loses its Jagged Profile as Vegetation and Soils develop.

Question 24

State a UK Example of a Raised Beach.

Answer 24

Corbyn’s Head, Torquay, Devon

Question 25

State a UK EXample of a Fossil Cliff

Answer 25

Lyme Regis, Dorset

Question 26

Define Submergent Features.

Answer 26

Landforms created by a Rise in Sea Level that Floods the Coast.

Question 27

State 3 types of Submergent Landforms.

Answer 27

-Fjords -Dalmation Coasts -Rias

Question 28

Explain the Formation and Characteristics of a Fjord. (6)

Answer 28

-Formed due to Eustatic Change. -River carves a V-Shaped Valley into the Landscape. -During an Ice-Age, a Glacier moves through the Valley eroding it via Plucking and Abrasion to create a U-Shaped Valley. -Global Warming causes Glacial Melt and Retreat Inland. -Due to the Glacier eroding the Valley below Sea Level, the Valley is Flooded creating a Fjord. -Fjords are Narrow with Steep Sides.

Question 29

State an Example of a Fjord in Norway.

Answer 29

Sognefjord which is over 1000m Deep.

Question 30

Explain the Formation of a Dalmation Coast.

Answer 30

Eustatic Change Floods Valleys that lie Parallel to the Coast leaving Islands.

Question 31

State an Example of a Dalmation Coast in Croatia.

Answer 31

The Dalmation Coast, Croatia.

Question 32

Explain the Formation of Rias. (2)

Answer 32

-Eustatic Change partially floods a V-Shaped River Valley. -They're Wide and Deep at the Mouth , becoming Narrower and Shallower the Further Inland they Travel.

Question 33

State an UK Example of a Ria.

Answer 33

Milford Haven, Pembrokeshire, Wales

Question 34

State 2 Stats that highlight Potential Impact of Sea Level rise on Humans.

Answer 34

-75% of the World's Cities are Coastal. -More than 1 Billion People live on High Risk Coasts.

Question 35

State and Explain 4 Impacts of Sea Level Rise on Coastal Areas.

Answer 35

-Storms increasing in Magnitude and Frequency due to Changes in Ocean Temperatures. -Submergence of Low-Lying Coastal Towns/Islands. -Contamination of Water Sources on Farmland can Increase Salinity which can dammage crops and make Land Infertile. -Increased Rates of Coastal Erosion putting Ecosystems, Homes and Buisnesses at Risk.

Question 36

State the Potential Sea Level Rise Depth if the Earth's Ice Sheets Melt.

Answer 36

72m.

Question 37

State 2 Adverse Effects of Climate Change on the UK Coastline.

Answer 37

-Major Transport and Energy Infrastructure is Situated near the Coast on Low-Lying Ground. -High-Grade Agricultural Land and Cities like London are at Risk from Coastal Flooding in the Long-term.