Coasts- Lesson 1 Coastal Systems

Question 1

What is a closed system?

Answer 1

A closed system has transfers of energy both into and beyond the system boundary but no transfer of matter

Question 2

What is an open system?

Answer 2

An open system is where matter and energy can be transferred from the system across the boundary into the surrounding environment. Examples are most types of ecosystems

Question 3

What is positive feedback?

Answer 3

Positive feedback is when the effects of an action are amplified or multiplied by subsequent knock on or secondary effects

Question 4

What is negative feedback?

Answer 4

Negative feedback is where the effects of an action are nullified by its subsequent knock-on effects

Question 5

What is an example of negative feedback?

Answer 5

• a beach is a equilibrium
• sediment is eroded from beach in a storm
• sediment is deposited offshore forming a offshore bar
• waves now forced to break before reaching the beach dissipating energy and reducing further erosion
• when storm calms, conditions rework sediments from the offshore bar back to the beach

Question 6

What does the coast system consist of?

Answer 6

Inputs and outputs of energy

Question 7

What are coastal inputs?

Answer 7

• wave energy
• tides
• currents
• winds
• storm surges
• tidal waves
• changes in sea level
• sediment
• human activities

Question 8

What are outputs to the costal system?

Answer 8

-loss of wave energy
-depositional landforms:
Beaches
Mudflats
Sand dunes
Coral reefs
-erosions landforms:
Cliffs
Shore platforms

Question 9

What are spatial variations in energy a result of?

Answer 9

Variations in wind strength and the number and intensity of storms

Question 10

Where are storms most frequent?

Answer 10

• In mid-latitudes where low-pressure systems (depressions) are frequent
• in the tropics where tropical low-pressure systems (hurricanes) occur

Question 11

Temporal variations involve?

Answer 11

Seasonal or daily differences

Question 12

In mid-latitudes, what is more common in each season?

Answer 12

• winter, depressions are more frequent

- summer, hurricanes are more frequent

Question 13

Open coastlines in high latitudes with high energy are dominated by?

Answer 13

Erosion

Question 14

Why are high latitude, high energy coastlines dominated by erosion?

Answer 14

Because they have high wave and wind activity

Question 15

Low energy coastlines are therefore?

Answer 15

Sheltered and dominated by deposition due to low wave and wind but greater tide activity