Tsunamis-Lesson 9 Flashcards
Is a tsunami a Primary or Secondary earthquake hazard?
secondary
What is most common cause of a Tsunami?
Tectonic activity at subduction zones
Other than earthquakes what are 3 other causes of tsunami’s
Landslides, volcanic eruptions and asteroid strikes
Where are 90% of tsunamis generated?
Within the pacific basin
Since what year has the tsunami warning system in hawaii been in place?
1968
What are a series of waves called in a tsunami?
A wave train
In open ocean what is the wavelength and waveheight like?
A very long wavelength
Shorter waveheight
What happens to the velocity of the wave when it arrives in shallow waters?
The velocity decreases due to friction with the seabed
What happens to the height of the wave when it gets into shallower water?
Wave height increases
What happens to the wavelength of a wave when it reaches the shore?
Wavelength decreases (to 20km)
What are tsunamis created by?
Water column displacement caused by undersea plate movements
