tsunamis

Question 1

what is a tsunami?

Answer 1

series of waves caused by the displacement of large quantities of water- water column displacement. this is caused by submarine earthquakes, landslides or volcanic eruptions.

Question 2

how are tsunamis formed?

Answer 2

1. plate shifts abruptly causing earthquake and displacing water/ material from eruption or landslide falls into sea displacing water.
2. waves are generated and move out in all directions across the ocean (some as fast as 600km)
3. as tsunami wave reaches shallower water friction between wave and seabed increases, the tsunami wave slows down and compresses- decreasing wavelength but increasing wave height.
4. wave height continues to increase and currents intensify becoming threat and a danger as it approaches the shore.

Question 3

affecting factors

Answer 3

• duration of event: longer = more damage
• wave amplitude
• coastline geography: shallow/coastal plains/ river valleys
• coastline ecosystem
• time of day/quality of early warning
• degree of coastal development and its prox. to the coast