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Hello all,
Quick question. I have been looking at a house on the ocean in Waa Waa. I would imagine if a whopper of a Tsunami came Barreling on, the house would be toast. What's the general idea of what would happen to beachfront homes in the Waa Waa, Opihikao area in the Event of a head on large Tsunami? I know the evac areas. Any additional info, guesses? Thanks
AKpilot
We're all here, because we're not all there!
We're all here, because we're not all there!
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They would be gone.
Assume the best and ask questions.
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during the japanese tsunami last year, which was pretty small here, a house was swept into kealakekua bay. there was millions of dollars of damage in hawaii. a big tsunami would be devastating.
with that being said, i would prefer if they removed the hilo breakwall. it doesn't seem like it would do much to help during a tsunami, and the bay needs a good rinsing out.
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quote:
Originally posted by bluesboy
with that being said, i would prefer if they removed the hilo breakwall. it doesn't seem like it would do much to help during a tsunami, and the bay needs a good rinsing out.
Actually, the breakwater prevented a lot more damage from the 1960 tsunami that could have happened. It didn't completely hold up though and a large part washed away. Water quality tests afterward found the tsunami had actually washed away a lot of the pollution that had existed in Hilo bay from sugar cane arsenic use and raw sewage accumulation.
"The breakwater was completed in 1929, and had the effect of trapping much of the debris from the Wailuku and Wailoa rivers inside the bay. Today the trapped silt and turbidity are blamed for the still-declining coral reef and reduced marine life inside the breakwater."
There is recognition that something needs to be done with the breakwater and the Army Corp of Engineers have been studying it since the 1970's to determine what needs to be done, whether tsunami protection was a priority or for more natural ocean movement to clean the bay even more. The last plan being studied was extending the breakwater with a more "porous" section, to allow the bay to flush out and building up the main section to better withstand another tsunami.
The main factor is which way the tsunami originates. If a major earthquake happens on the west coast, from Alaska to Chile, that will be the most damaging for the east side of Hawaii island. An interesting experiment is take the tsunami pattern from Fukushima and overlay it on Chile, rotate it around until it is facing Hawaii island. Yes, that will wipe out Waawaa. In 1960, there was almost nobody living on the Puna coastline. It will be a different story next time around.
*Japanese tourist on bus through Pahoa, "Is this still America?*
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How high a sea cliff would one have to build a home on to be safe from a 1960 type tsunami?
Are the homes on the cliff immediately north of the Wailuku Bridge tsunami safe?
-Veritas odium parit”(Terence 195–159 BC))-"Truth begets hatred".
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Safe is a matter of proportion. I have read there is evidence of an ancient tsunami at about the 1,000 ft. elevation.
Bear this in mind: there is nothing made by man that cannot be defeated by nature.
The good news is that we have tsunami warning systems to warn of most (but perhaps not all) tsunami. It is prudent to respect the warnings.
If you are overly concerned about tsunami it might also be wise to look for ocean view property at a higher elevation.
Assume the best and ask questions.
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A really cool thing to do is go to downtown Hilo old town and look up at to the top of the building to see the date it was built, and realize many of those survived both the 1946 and the 1960 tsunami's. They must have been totally under water and they are still around. Going around to some of the other historical sites, as much damage was caused, the amount that survived, even from the 1800's, are made even more amazing.
*Japanese tourist on bus through Pahoa, "Is this still America?*
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quote:
Originally posted by Cagary
How high a sea cliff would one have to build a home on to be safe from a 1960 type tsunami?
Are the homes on the cliff immediately north of the Wailuku Bridge tsunami safe?
http://en.wikipedia.org/wiki/Lituya_Bay
Lituya Bay, Alaska mega tsunami. Taller than the Empire State building
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Perhaps you could add to your research by visiting the Tsunami Museum in Hilo. Also look up Hilina slump. According to wikipedia this is the cause of the Mega Tsunamis in the past. For the most part we have plenty of warning if a Tsunami is coming. However if you ever feel a strong earthquake here and you are anywhere near the ocean you need to move fast. They are rare but it is good to be aware.
From Wikipedia
The Hilina Slump is a 5,000 cubic mile (20,000 kilometre³) chunk of the big island of Hawaii on the south flank of the Kilauea volcano. Between 1990 and 1993, Global Positioning System measurements showed a southward displacement of the south flank of Kilauea up to approximately 10 centimeters per year.[1] The slump has the potential of breaking away at a faster pace in the form of an underwater landslide. In Hawaii, landslides of this nature are called debris avalanches. If the entire Hilina Slump did slide into the ocean at once, it could cause an earthquake in excess of a 9 in magnitude and a megatsunami. Previous megatsunamis in Hawaii 110,000 years ago caused by similar geological phenomena created waves 1,600 feet (500 m) tall.[2] Were such a megatsunami to occur again, it would threaten the entire Pacific Rim.
On April 2, 1868, an earthquake in this area with a magnitude estimated between 7.25 and 7.75 rocked the southeast coast of Hawaii. It triggered a landslide on the slopes of the Mauna Loa volcano, five miles (8 km) north of Pahala, killing 31 persons. A tsunami claimed 46 additional lives. The villages of Punalu#699;u, Ninole, Kawaa, Honuapo, and Keauhou Landing were severely damaged. According to one account, the tsunami "rolled in over the tops of the coconut trees, probably 60 feet (20 m) high ... inland a distance of a quarter of a mile in some places, taking out to sea when it returned, houses, men, women, and almost everything movable."[3]
On November 29, 1975, a 40 mile (60 km) wide section of the Hilina Slump slid 11 feet (3 m) into the ocean, widening the crack by 26 ft (8 m). This movement caused a 7.2 magnitude earthquake and a 50 foot (15 m) high tsunami. Oceanfront properties were washed off their foundations in Punalu#699;u. Two deaths were reported at Halape, and 19 other persons were injured. The shoreline at Keauhou Bay was dramatically altered.[4]
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To Funkstopper's point, whenever I drive through Waa Waa, it always strikes me as a place that would be tough to evacuate quickly, certainly if one is trying to get to high ground immediately after a big earthquake. But...I'd still love to live there.
Tim
A superior man is modest in his speech, but exceeds in his actions--Confucius
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