HAWAII KAI TSUNAMI HAZARD

1
HAWAII KAI TSUNAMI HAZARD

• July 2006

2
(No Transcript)
3
(No Transcript)
4
(No Transcript)
5
(No Transcript)
6
(No Transcript)
7
(No Transcript)
8
SWAN Model for Hawaii KaiClick above for Movie

• On CD-ROM in Numerical Modeling of Water Waves
  CRC Press (2004)
• A train of 3 meter high, 1500 second tsunami
  waves. 30 DeChezy Friction.
• Modeled 15 years ago.
• Topography of bay from Sea Engineering depth
  measurements for Ferry Feasibility Study.
• Floods up to 5 meters inside front of bay and a
  min of 2 meters in back of bay by third wave.

9
Hambantota, Sri Lanka

• Dr. Hermann Fritz surveyed after December 26,
  2004 Indian Ocean Tsunami
• Noted that it was similar to Hawaii Kai with reef
  outside with a channel under a road along the
  sea shore into a large shallow lake.

10
(No Transcript)
11
(No Transcript)
12
Hambantota Tsunami

• Wave arrived a little over 2 hours after
  earthquake. The first wave was about 1 meter
  high and the second wave was up to 10 meters high
  about 10 minutes later.
• Houses over 1 kilometer inland were demolished.

13
Tsunami Effects

• Little of the town was left standing with no
  water, electricity or communications.
• One thousand houses along the Hambantota-Tissa
  road, town-council residences, shops and other
  buildings destroyed. Many homes located near the
  Hambantona harbor were completely washed away.

14
Loss of Life

• When the tsunami hit, hundreds of local people
  were visiting Sunday markets.
• Two to three thousand people were promenading
  along Hambantota harbor when the tsunami wave
  struck.
• The overwhelming majority of these died.
• Over 4500 died in low-lying coastal strip

15
(No Transcript)
16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
19
(No Transcript)
20
(No Transcript)
21
(No Transcript)
22
(No Transcript)
23
(No Transcript)
24
(No Transcript)
25
(No Transcript)
26
(No Transcript)
27
(No Transcript)
28
(No Transcript)
29
HAMBANTOTA, SRI LANKADecember 26, 2006 Tsunami

• DEATH ZONE WAS AREA BELOW 10 METERS and LESS
  THAN 1 KILOMETER FROM SHORE.

30
Multiple Tsunami Waves

• Often populated areas along coasts are located in
  low-lying and flat regions that together with
  natural and man made obstacles make retreat of
  the flood caused by first tsunami wave to be
  slow. Subsequent waves ride over a region already
  flooded resulting in higher and faster waves.

31
Sri Lanka Multiple Tsunami Waves

• The multiple wave phenomenon was observed
  throughout the Sri Lanka coast.
• http//www.asce.org/page/?id53
• It wasnt one wave, it came in great surges,
  each one deeper than the last and pushing the
  water that had come in before it in front of it.

32
Sri Lanka Multiple Tsunami Waves

• Most witnesses described 3 main waves.
• The first knocked them off their feet, the second
  picked them up and carried them, often up to 50
  km/hr, and the third bore them up to 15 meters
  high or sucked them under.

33
Fritz Indian Ocean Tsunami Survey Conclusions

• Evacuate all areas below 15 meters above sea
  level and within 0.25 mile of shoreline or along
  rivers.
• Evacuate all areas below 10 meters above sea
  level and within 1.0 mile of shoreline or along
  rivers.
• Evacuate all areas below 5 meters above sea level
  and within 3 miles of shoreline.

34

• "The Hawaii Kai evacuation zone should include
  all areas
• below 5 meters above sea level"
•  
• Consider the 1946 historical observations as
  recorded in
• United States Tsunamis - 1690-1988 (page 66)
•  
• Waipio Valley - 12 meter run-up amplitude
• Swept 1 mile into valley, pulled away homes and
  people
• and left only foundations
•  
• Waikolu Valley, Molokai - 16.4 meter run-up
  amplitude
• Destroyed farms and buildings up entire valley.
•  
• Makapuu Point, Oahu - 11.1 meter run-up
  amplitude
• Destroyed the nearby Ranch buildings with 3
  waves (Helsley
• from wave deposits) leaving only foundations.
•  
• Three wide valleys destroyed by the 1946 tsunami
  are

35
HAWAII KAI

• MINIMUM Evacuation zone should include all area
  below 5 meters above sea level.
• 3 Meter Tsunami Flooding Graphic
• MOVIE AVAILABLE ON NMWW DVD

36
Sandy Beach and Queens Gate

• 3 meter, 1500 sec Tsunami
• 10 meter, 1500 sec Tsunami
• From Numerical Modeling of Water Waves CD-ROM,
  CRC Press (2004).
• All of Queens Gate up to Hawaii Kai Drive should
  be in evacuation zone.
• MOVIE AVAILABLE ON NMWW DVD

37
Queens Gate