Coastal Flooding Flashcards
What is a storm surge?
Sudden rises in sea level caused by very strong winds, normally found in hurricanes and cyclones.
How do storm surges cause coastal flooding?
Strong winds push ocean water on the surface on top of more water, increasing sea level and therefore flooding coastlines.
What conditions cause a storm surge?
Low air pressure is created which also contributes to strong winds and sea level rise itself.
When are storm surges most dangerous?
Most dangerous during high tides as the sea will already be elevated. They are dangerous near defended areas as the waves may overcome the defences.
What causes the sea level to rise?
Climate change or isostatic rebound.
How do rising sea levels lead to coastal flooding?
Low lying coastal areas are permanently flooded by sea. As ice melts or isostatic rebound or weaker winds increase sea level enough to flood.
What are Tsunamis?
Giant waves resulting from earthquakes, volcanic eruption or any sort of major displacement of water in the ocean.
Why are Tsunamis so dangerous?
Inability to detect/predict and they move very quickly.
How are Tsunamis formed?
Amplitude of waves at source are very low, as wave approaches the shore they are slowed and therefore height increases exponentially, without breaking.
Why do Tsunamis create so much damage?
The waves hit the coast with so much energy that they are able to travel several miles inland, where they collect debris and deposit it when energy dissipates.
What is Reclaimed Land?
Land that has been gained from sea due to coastal management or lowered sea levels.
Why is reclaimed land vulnerable to coastal flooding?
It is low lying and flat so a small rise from a mild storm surge in sea level is enough to flood and cause extensive damage.
