Lec #1. Controls on coatal formations and barrier Islands

Question 1

Define a Physical Process

Answer 1

The forces that create coastal habitats which create stressed, biodynamic and dynamic habitats

Question 2

Explain a barrier island

Answer 2

Form parallel to land, could be attached at one end or not at all, normally made up for sand sized particles. Habitat could be diverse or desolate.

Question 3

What key conditions are needed for barrier island formation (4)

Answer 3

Coastline Gradient
Sediment type
Tidal Conditions
Input of sediment

Question 4

What are the two possible inputs of sediment for barrier island formation

Answer 4

Fluvial and Longshore drift

Question 5

What relationship between erosion and deposition does there need to be for barrier island formation

Answer 5

Deposition must be occurring faster than erosion

Question 6

Which wave form brings eroision

Answer 6

Larger waves

Question 7

What wave size or form brings depostion

Answer 7

Small to medium sized waves

Question 8

What factor effects the size of the waves

Answer 8

Waves are effected by the gradient of the slope, a shallower slope pushes waves up (shoaling) which causes erosion due to friction

Question 9

Discuss the importance of plate tectonics for barrier island formation

Answer 9

These can cause the steep gradient needed for depositional waves

Question 10

Explain the importance of rivers in barrier island formation

Answer 10

Can bring the deposition of sediment. more rivers = more discharge = more sediment

Question 11

Explain the signifcance of tidal ranges in barrier island formation

Answer 11

High energy enviorments so a small tide allows for accullation

Question 12

Give an example (real world) of a barrier island

Answer 12

Galveston, Texas

Question 13

Explain the differences between the land facing and sea facing side

Answer 13

Land side would have vegetation as it is more stable where as the sea facing side is constantly changing and lacks stablilty

Question 14

Explain the imporatnce of storm surges in barrier island formation

Answer 14

Storms surges have the power to overtop the barrier island taking sediment from the seaward side to the landward side as a method of replenishment

Question 15

How does sea level rise effect barrier islands

Answer 15

As tides change a barrier island undergoes movement either toward or away from the land

Question 16

Explain how tectonic activity effects coastal enviroments (2 points)

Answer 16

1) Sea level rise through sea floor spreading and uplift of mid oceans ridges.
2) nature of the sea floor topography dictated by tectonic activity

Question 17

Explain the theory of isostatic rebound

Answer 17

During the last glacial maximum a lot of land was covered by ice, as this melted the weight of the ice decreased and now the plates are rebounding as compression of sediment is reversed

Question 18

How does isostatic rebound effect the UK

Answer 18

The North of the UK is rising by 3mm a year and the South is sinking by 1mm a year

Question 19

Explain thermoexpansion

Answer 19

As atoms in water molecules become warmer they become more excited which causes an expansion in volume

Question 20

How much does thermoexpansion account for in terms of eustatic sea level rise

Answer 20

60%

Question 21

How does glacial melting effect sea level rise

Answer 21

Obviously because the ice is fucking melting there will be more water

Question 22

What can oxygen isotopes tell us

Answer 22

Oxygen isotopes (O18) will change in concentration depending on sea level rise

Question 23

What numerical values can show how isotope concentration has changed with sea level

Answer 23

a 0.1 concentration change means a 10m rise in sea level

Question 24

What can be created with oxygen isotopes

Answer 24

Oxygen isotope curves which show the change in sea level throughout history

Question 25

What are the two geological controls on coastlines?

Answer 25

Placements on continents and sea floor spreading rates

Question 26

What are the three climatic controls on coastlines

Answer 26

Isostatic rebound, glacial melting and thermoexpansion

Question 27

what are the two sedimentation processes that control coastlines

Answer 27

Longshore drift and fluvial deposits

Question 28

What is the difference between transgressive and regressive sea level change

Answer 28

Transgressive pushes coast in land and regressive land is reclaimed as sea retreats

Question 29

What are the two types of sea level rise

Answer 29

Relative and Eustatic

Question 30

Explain relative sea level rise

Answer 30

Reference to sea level changes relative to land, operates on a regional and local level

Question 31

What is eustatic sea level rise

Answer 31

References to a change in the world wide sea level rise, unrelated to local climate changes

Question 32

What are the four evidence for sea level rise?

Answer 32

Deposition of marine sediments now on land,
Oxygen isotopes,
Submerged marine coastlines,
coastal features now well above sea level

Question 33

What are coastal plains?

Answer 33

The are physiographic provinces between the land and the ocean which contain sediments from marine origins

Question 34

Discuss fossil evidence as evidence (evolution)

Answer 34

As sea levels rise species can become isolated and evolve in different ways (Galapagos Islands)

Question 35

Discuss the evidence from facies sequences

Answer 35

Discomformities in the rock record give evidence for sea level rise

Question 36

What evidence does submerged coasts show

Answer 36

Obviously that sea level has rise

Question 37

what evidence does emerged coasts show

Answer 37

Obviously that sea level has fallen

Question 38

Is James a cunt?

Answer 38

Yes, James is a massive massive cunt.