Tsunami

Question 1

Wave length, wave height and speed

Answer 1

They have a long wave length and a low wave height in the open ocean. They travel quickly at speeds over 700 km per hour. When they reach shallow water or near land their height rapidly increase

Question 2

Creation of a tsunami

Answer 2

They are giant sea walls generated by:
-shallow focus, underwater earthquakes
Or
-underwater volcanic eruptions
-underwater debris slides

Question 3

Factors which determine effects when it hits land

Answer 3

1) height of wave/ distanced travelled
2) length of event
3) extent warnings were given
4) physical geography of coastal area

Question 4

Sequence of events

Answer 4

Rapid movement of ocean floor dispenses a column of water

Series of waves travel outwards at heights less than 3ft in open ocean

As waves approach the land it’s energy is compressed into a smaller space, forcing it to gain height

Question 5

Responding to earthquakes

Predict

Answer 5

• Monitoring ground water levels
• Monitoring release of radon gas
• Monitoring animal behaviour

Question 6

Responding to earthquakes

Prepare

Answer 6

Organising drills so people know what to do

Question 7

Responding to earthquakes

Protect

Answer 7

Modifying the human and built environment

Question 8

Effects- boats

Answer 8

Wave will wash boats inland then the backwash will drag them out to sea

Question 9

Effects- water

Answer 9

People are drowned or injured by the tsunami by the water itself or the debris which the water contians

Question 10

Effects- buildings

Answer 10

Buildings, roads, bridges, harbour structures, trees and even soil are washed away. Most tsunami’s have an effect at least 500-600m inland depending on coastal geography

Question 11

Where they are generated

Answer 11

Around 90% of all tsunamis are generated within the Pacific basin, associated with the tectonic activity taking place around the edges

Question 12

First warnings

Answer 12

A first warning could be reduction in sea level due to the wave trough in front of the tsunami wave also known as drawdown. After this the wave comes behind reaching heights of up to 25m and there is normally a number of waves