Tsunami Notes

1.Basic Information

• Tsunami is derived from a Japanese word
• A tsunami is not a single wave but a series of waves called a wave train. The first wave is usually not the most destructive, but it is the most deceiving. Each wave can be up to an hour apart or as close as five minutes
• Tsunamis are different than tidal waves
• Those on a boat in the ocean generally will not notice the tsunami because it only lifts the boat a small amount
• The tsunami gains speed and force as the water becomes shallower and nears land

2. National Geographic Video

3. Where Do Tsunamis Occur?

• The U.S. National Oceanic and Atmospheric Administration (NOAA) state that the Pacific is by far the most active tsunami zone
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4. Warning Systems

• NOAA operates 2 tsunami warning centers
  • ATWC serves Alaska, British Columbia, Washington, Oregon, and California
  • PTWC serves Hawaii
• In 1965, the PTWC assumed the international warning systems responsibilities of PTWS.
• The PTWS is comprised of 26 international member countries
• Most warning systems only look for underground seismic activity, not changes in water pressure or speed
• The tsunami warning system in the Pacific has a false alarm rate of 75%

5. Earthquake tsunamis

• There are monitoring systems at ocean floor that records seismic activity that is then relayed to warning centers
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6. Volcano tsunamis

• 1883 Krakatau eruption caused a tsunami of 130 ft that stripped vegetation and washed about 3,000 people out to sea
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7. Meteor tsunamis

• Scientists have found traces of an asteroid-collision event that occurred 3.5 billion years ago that created a massive tsunami covering everything across the globe except the tallest mountains.

8. In summary...

• Earthquake vibrating data may give us incorrect tsunami forecasting.
• The strength of the vibration and tsunami energy are not exactly proportional
• Therefore, offshore and coastal direct observation system and water pressure sensors should be included into monitoring systems

9. DART

• Deep-ocean Assessment and Reporting of Tsunami (DART)
• 6 in 2001
• 39 in 2008
• DART I Model
  • Became operational in 2003 but were all were replaced by DART II Model in early 2008
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• Dart II Model
  • Collects temperature and pressure at 15 second intervals
  • uses satellite communication system
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10. Tsunami Buoys: Image

11. Warning Signs: Image