[Unit 2B: Enquiry Question 3]

Question 1

what happens and how to sea level when global temp falls

Answer 1

ice builds up. oceans contract in volume. sea level falls

Question 2

what happens and how to sea level when global temp rises

Answer 2

ice melts. ocean expands due to thermal expansion. sea level rises

Question 3

what is eustatic change

Answer 3

rise or fall in water level caused by change in volume of water. this is global change

Question 4

what is isostatic change

Answer 4

local rise or fall in land level. ice collected on land. extra weight causes land to sink. as it melts land rebounds to original position (isostatic readjustment)

Question 5

what are the two forms of marine regression

Answer 5

eustatic fall in sea level:
-ice sheets form
-water evaporates global fall in sea level
isostatic fall in sea level:
-ice sheets create weight
-it melts surface rebounds
-lifts land out of sea

Question 6

what type of coastline does marine regression form

Answer 6

emergent coast line

Question 7

what are the two types of marine transgression

Answer 7

eustatic rise in sea level:
-melting ice returns to water
-sea level rises
isostatic rise in sea level:
-land sinks at coast due to deposition
-adding weight to crust

Question 8

what type of coastline does marine transgression form

Answer 8

submergent coast line

Question 9

what are three types of submergent coastlines

Answer 9

Ria
Fjord
Fjard

Question 10

what is a Ria. How does it form. Give an example

Answer 10

flooded river valley.
during ice age some areas covered w frozen ground
rivers carved valleys with steeper sides
ice melted and drowned the mouth of valleys
for example: Plymouth Sound

Question 11

what is a Fjord. How does it form. give an example

Answer 11

flooded glaciated valley
glaciers eroded U shaped valleys to coast at that time
ice melted flooding valley creating deep water inlets w steep sides
For example: Milford Sound

Question 12

What is a Fjard. How does it form. Give an example

Answer 12

flooded inlet with low rocky banks
formed by post-glacial drowning of glaciated lowland rocky terrain.
For example: Gulf of Finland

Question 13

what are two types of emergent coastlines

Answer 13

raised beach
fossil cliff

Question 14

what is a Raised beach. How does it form. Give an example

Answer 14

former beach now above high tideline
different level indicating different stage of uplift
For example: Templetown

Question 15

what is a fossil cliff. How does it form. Give an example

Answer 15

near vertical slope
formed by marine processes but now inland
coastal erosional features may still be visible
For example: The Wairau Valley

Question 16

how much is sea level rising per year

Answer 16

2mm

Question 17

between what years was sea level stable

Answer 17

1800-1870

Question 18

what year did sea level rise start accelerating rapidly

Answer 18

1940/1980

Question 19

what are the three components that affect sea level rise

Answer 19

glaciers
thermal expansion
ice sheets

Question 20

give two examples of a coastline that has changed locally due to tectonic activity

Answer 20

Turakirae Head - New Zealand
lots of earthquakes have repeatedly lifted shoreline by several meters

2004 Indian Ocean Tsunami:
-coastline Aceh dropped by 1m
-some islands raised by 2m
-tectonic subsidence formed rias.

Question 21

what factors cause some coasts to erode faster (5)

Answer 21

long wave fetch & large destructive waves
soft geology
cliffs with structural weaknesses
strong longshore drift
cliffs vulnerable to mass movement

Question 22

what percentage of people live in the Egypt Delta

Answer 22

95% of Egypt’s population

Question 23

What is being caused by sea level rise and more frequent coastal flooding. In the Egypt Delta

Answer 23

salt intrusion

Question 24

according to our best models, how much of Egypt’s Delta land is going to be lost by 2100

Answer 24

25%

Question 25

according to a 2015 study, how much of the Nile Delta is highly vulnerable?

Answer 25

32.4%

Question 26

how does weathering increase coastal retreat

Answer 26

weakens rock, increasing erosion rate

Question 27

how does mass movement increase coastal retreat

Answer 27

moves sediments to base of costal slope. where transportation moves sediment away allowing for further retreat

Question 28

is mass movement or wave action stronger

Answer 28

mass movement

Question 29

give an example of hard engineering being presented as powerless

Answer 29

Norfolk. cliff still retreats due to slumping

Question 30

what factors influence coastal recession rates

Answer 30

wind direction & fetch tides storms seasons weather systems

Question 31

what is the dominant wind

Answer 31

most powerful wind direction. dominant wind matches longest fetch

Question 32

what is the prevailing wind

Answer 32

most common wind direction

Question 33

how does wind direction and fetch influence coastal recession rates

Answer 33

increase rate if prevailing winds are directly onshore. larger fetch increase rate as more energy. short term factor.

Question 34

what distance can the fetch reach up to in North Northfolk

Answer 34

16,000km

Question 35

how do tides influence coastal recession rates

Answer 35

increase rate in higher tides (deeper water) -as there is increased energy in the backshore every 12 hours is high tide twice every lunar month is spring tide shorter term

Question 36

how do storms influence coastal recession rates

Answer 36

cause destructive waves which increases rate global warming is increasing frequency & severity of storms short term

Question 37

how do seasons influence coastal recession rates

Answer 37

more storms in winter summer tropical cyclones El Nino (every 2-7 years)/ La Nina long term

Question 38

how do weather systems influence coastal recession rates

Answer 38

interaction between warm and cold air masses produce anticyclones and depressions. high pressure anticyclones produce nice weather so more constructive, gentle waves. so decreases rate. low pressure depressions produce stormy conditions. so increases rate (take several days to pass)

Question 39

give 6 reasons why people live in coastal regions

Answer 39

trade scenery fishing fertile soil tourism transport

Question 40

why are deltas vulnerable.

Answer 40

sediment trapped upstream by dams sea levels storm surges ground water extraction causes subsidence river straightening causes faster river flow destruction of mangrove forest exposes coast

Question 41

A fall of 1 millibar in air pressure causes a rise of how much in local sea level

Answer 41

1cm

Question 42

What conditions can worsen a severe weather event

Answer 42

strong winds during hightide or spring tide coastline narrows into funnel shape

Question 43

give some statistics on global warming based off the 2023 IPCC report

Answer 43

- 50% of wetland lost over last 100yrs due to humans - sea level rise of around 0.55m by 2100 - intensified and more frequent tropical cyclones over 21st century - 6-17km^2 land expected to be lost during 21st century.