Tsunami Evacuation Maps being revised due to historic Kau'ai sinkhole discovery. (Honolulu: 2014, insurance)
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
Scientists studying a massive 500 year old debris field on Kau'ai, found in a huge sinkhole, have concluded that it was caused by a giant tsunami that hit there, dwarfing the recorded tsunamis of the modern era, and prompting emergency planners to more than double Hawai'i's planned evacuation areas.
Quote:
A mass of marine debris discovered in a giant sinkhole in the Hawaiian islands provides evidence that at least one mammoth tsunami, larger than any in Hawaii's recorded history, has struck the islands, and that a similar disaster could happen again, new research finds. Scientists are reporting that a wall of water up to nine meters (30 feet) high surged onto Hawaiian shores about 500 years ago. A 9.0-magnitude earthquake off the coast of the Aleutian Islands triggered the mighty wave, which left behind up to nine shipping containers worth of ocean sediment in a sinkhole on the island of Kauai.
The tsunami was at least three times the size of a 1946 tsunami that was the most destructive in Hawaii's recent history, according to the new study that examined deposits believed to have come from the extreme event and used models to show how it might have occurred. Tsunamis of this magnitude are rare events. An earthquake in the eastern Aleutian Trench big enough to generate a massive tsunami like the one in the study is expected to occur once every thousand years, meaning that there is a 0.1 percent chance of it happening in any given year – the same probability as the 2011 Tohoku earthquake that struck Japan, according to Gerald Fryer, a geophysicist at the Pacific Tsunami Warning Center in Ewa Beach, Hawaii.
Nevertheless, the new research has prompted Honolulu officials to revise their tsunami evacuation maps to account for the possibility of an extreme tsunami hitting the county of nearly 1 million people. The new maps would more than double the area of evacuation in some locations, according to Fryer.
Thanks Scott, that was a better article than the three I had read. Since so many people never open the links that get posted here, I like to post a snip from the article for people to get a sense of the article, and decide if they want to read more... so I'll do that now with your article:
Quote:
New Evidence Suggests Hawaii Could Be Hit By A Massive Tsunami
The discovery of a massive debris pile in a giant sinkhole in the Hawaiian islands suggests that the region was hit by a mammoth tsunami about 500 years ago. It was larger than any in Hawaii's recorded history, so scientists are now worrying that a similar disaster could happen again.
Top image: Breach of the Miyako Seawall in Japan on March 11, 2011 (Toru Hanai/Reuters).
By studying the deposits left by the tsunami, and by creating computer models to show how it might have occurred, researchers from the University of Hawaii at Manoa have painted a picture of the cataclysmic event.
Sometime between 1425 and 1665 A.D., a 9.0 earthquake (and possibly as high as 9.2) struck the eastern Aleutians. It triggered a tsunami that, by the time it reached the Hawaiian islands, featured a wall of water up to 30 feet (9 meters) high. It left behind up to nine shipping containers worth of ocean sediment in a sinkhole on the island of Kauai. It was three times bigger than the tsunami that hit the region in 1946.
Tsunamis like this are extremely rare, and the paleogeologists are ascribing a 0.1% chance of it happening in any given year. That's the same degree of risk as the 2011 Tohoku earthquake that struck Japan in in 2011.
Despite the low probability, the new research has prompted Honolulu officials to revise their tsunami evacuation maps to account for the possibility. The new maps more than double the area of evacuation in some locations.
There are also several excellent graphics in the article showing several models of different tsunami paths which I won't show here due to copyright restrictions.
Thanks Scott, that was a better article than the three I had read. Since so many people never open the links that get posted here, I like to post a snip from the article for people to get a sense of the article, and decide if they want to read more... so I'll do that now with your article:
There are also several excellent graphics in the article showing several models of different tsunami paths which I won't show here due to copyright restrictions.
Also i remember reading about the islands where they were hit with a huge tsunami, when a huge part of Molokai broke off and slide into the ocean. Scary because of the makeup of the islands it can happen without warning. A big piece of the Big Island is cracking right now as i speak.
Also i remember reading about the islands where they were hit with a huge tsunami, when a huge part of Molokai broke off and slide into the ocean. Scary because of the makeup of the islands it can happen without warning.
I would say no, with modern weather monitoring and satellite sensors and so on, there is advanced warning of incoming tsunamis. But what the Fukushima disaster revealed was that the evacuation plan was insufficient, because it was based on a "100 year" worst case, rather than a 1,000 year worst case.
Now that the scientists have analyzed the impact of a "1,000 year" event in Hawai'i, it is prudent to revise our disaster plans appropriately. Nothing can protect property against such an extreme event, but the expanded plans can help prevent loss of life in the event of such a disaster.
Ok, where is Kau'ai??? Since this wasn't in an island specific thread - perhaps many people may miss it. Did you mean Kaua`i? Or, the commonly spelled, Kauai?
Even the county of Kaua`i/Kauai discourages a okina as nobody can find the content via google searches.
Unless of course, there is some other Kau'ai? Google didn't seem to know.
Ohmigard, what a disaster! It's a "1,000 hour" typo! We'll all be killed! Run for the hills!
I guess I mighta had a leetle too much okolehau when I wrote that, in celebration of being given Rep Point #9,400 here with a nice comment, just after I passed the 12,000 post mark, which I see have been read nearly 10,000,000 times. It feels nice to have so many people appreciate what I try to provide here, even if a couple of others aren't fans. Ol' Honest Abe was sure right on that score.
But the personal tsunami caused by the beef and bean burrito I made myself for dinner, now THAT was a disaster I should have been able to forecast better, especially after earlier rumblings knocked me out of bed. I think I'll forego my customary eruption alert on that one, with the flow rates and all and try to get back to sleep.
But the personal tsunami caused by the beef and bean burrito I made myself for dinner, now THAT was a disaster I should have been able to forecast better, especially after earlier rumblings knocked me out of bed. I think I'll forego my customary eruption alert on that one, with the flow rates and all and try to get back to sleep.
Jungjohann, is that you?
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.
Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
