Readings: Sea level fluctuations and changes

Question 1

Why are sea level fluctuations important?

Answer 1

They affect the
level at which wave action occurs and may also lead to horizontal movements of water in tidal and other currents. They thus have an effect on coastal erosion, transportation and deposition

Question 2

What are some common causes of short term fluctuations

Answer 2

• tides produced by the gravitational force of the moon and the sun
• storm surge,
• seasonal variations in pressure and wind
• patterns and changes in weather patterns on scale of years to decades such as the El Niæo Southern Oscillation (ENSO) cycle

Question 3

How can the position land effect coasts?

Answer 3

lead to inundation (transgression) or exposure (regression) of the land.

Question 4

What causes eustatic changes?

Answer 4

• changes in the volume of water in the ocean basins
• Isostatic loading and unloading due to the growth and decay of the ice sheets complicates the response
• tectonic forces lead to relative
  changes in the elevation of the coast locally and
  to changes in the ocean basins as a result of continental drift.

Question 5

What is mean sea level?

Answer 5

the average level of the sea at a point along the coastline, or in the open ocean

Question 6

what can impact tide gauge readings?

Answer 6

-changes in atmospheric pressure
-winds
- ocean currents
-sea surface temperature