Fodor's Travel Talk Forums - Earthquake/Tidal Wave question

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Earthquake/Tidal Wave question

Do the small cottage communities along Oahu's North Shore have tidal wave warning horns? I felt Alaska's 7.9 quake yesterday which prompted my question. I know the Hilo tidal wave was caused by an earthquake in Japan. We will be staying pretty close to the water. Am wondering if they have warning systems all along the coast, or are you on your own.

That is a very interesting question, Linda. I wonder if there were threats of tidal waves on any of the Pacific islands after the quake in Alaska. We have stayed in a small community on the windward side of Oahu and yes, they do have the tidal wave warning horns up on poles all along the coast. We always end up having that conversation about "running for the highlands" in the event. Any of our island fodors friends have insight here?

I think the paper said this quake was too far inland to cause tidal waves. The Anchorage one nearly 40 years ago caused several. Am glad to hear about the warning horns.

While hiking along the Na Pali coast, we saw markers designating the safe area in case of a Tsunami (tidal wave). I was shocked to see how high up the marker was frpom the water. I can only imagine the devastation to low lyin g areas.

The Alaska quake did not cause a tidal wave. I don't think that anyone has to worry too much about a tidal wave. Does anyone know when the last tidal wave hit the north shore of Oahu and how much damage was done? I have heard of tidal waves on the Big Island but not Oahu.

i did proofreading for a book last year on tidal waves in hawaii. as near as i can recall, 1975 or so: wave killed several boy scouts in kau in southeastern part of big island 1960 or so: wave generated by earthquake off chile killed 61 people in hilo, many of whom were waiting at the waterfront for a peek at the wave 1946 or so: wave killed abt 25 students and teachers at laupahoehoe on northern part of big island. don't recall anything abt other islands.

Sounds like there is a better chance of being killed by lightning than a tidal wave.

Don't just worry about your holiday destination and the people of Hawaii... While stressing that there is no indication it could happen soon, Atlantic coastlines in Europe, Africa and the Americas are under threat from a monster wave of Hollywood -- even Biblical -- proportions, scientists have warned. They fear that a massive landslide following a major volcanic eruption in the Canary Islands would send a 300-foot wave across the Atlantic, causing devastation to coastal towns and cities. British and U.S. scientists who have issued the warning predict that, in the worst-case scenario, the tidal wave would destroy the coasts of Florida and Brazil. But the Western Sahara, Portugal, Spain, France and parts of the UK would also be hit. They fear that the mega-wave -- know as a tsunami -- could be generated by part of a mountain twice the size of Britain's Isle of Man crashing into the sea following an eruption of the Cumbre Vieja volcano on La Palma, in the Canary Islands -- part of the Spanish island chain off West Africa. Travelling at speeds of up to 500mph, the tsunami would be an unstoppable force and would be the biggest-ever recorded in history. Previous research by Dr Simon Day, of the Benfield Greig Hazard Research Centre at University College London predicted that a future eruption of Cumbre Vieja was likely to cause the western flank of the mountain to slide into the sea. The energy released by the collapse would be equal to the electricity consumption of the entire U.S. in six months. With Dr Steven Ward, from the University of California, Dr Day has produced a new model that predicts more accurately how big the tsunami will be and where it will strike. Immediately after the landslide, a dome of water almost 900 metres (3,000 ft) high and tens of kilometres wide will form, only to collapse and rebound. Its first target was expected to be the West Saharan coast of Morocco, where the wave would measure a devastating 330ft from crest to trough. Propelled by a series of crests and troughs, the tsunami would travel a distance of almost 155 miles in just 10 minutes, the model predicts. Racing at the speed of a jet aircraft, it would reach Florida and the Caribbean in eight or nine hours. A wall of water 164ft high -- higher than Nelson's column in London's Trafalgar Square -- would smash into the coasts of Florida and the Caribbean islands, the forecast predicts. The northern coast of Brazil would be hit by a wave more than 130ft high. The wave would travel four or five miles inland, flattening everything in its path.

OK, that's the worst case scenario. And how likely would it be that there would be a major volcanic eruption in the Canary Islands?

A few years back during Bike Week in Daytona, a tidal wave/wall of water/storm surge or something like it, hit the beach in the middle of the night. I think it was caused by some underwater ground shift (not quite an earthquake). This wall of water came in about 25 ft. (or maybe it was 25 ft. tall). If this had happened in the middle of the day, it was predicted thousands of beach goers would have been killed. Not quite as bad as a Canary Island volcano disaster. Maybe Doommonger could get all the science into this.

More on Hawaiian tsunamis...between 1837 and 1960, there were damaging waves caused by distant earthquakes every 10 years or so on average. There have been none since 1960--makes you wonder if we're due for one. (The destructive 1975 tsunami on the Big Island was caused by a local earthquake.) The 1960 tsunami which killed 61 people in Hilo was caused by an 8.5 earthquake off the coast of Chile, and the worst one of all, which killed 159 in 1946, was caused by a 7.1 earthquake in the Aleutian islands of Alaska. The wave heights were as much as 55 feet above sea level in Pololu Valley on the Big Island. Hilo was the most severely affected by the 1946 and 1960 tsunamis because of the shape of its bay and the sea floor, but that doesn't mean you're safe on the other islands. The warning time for a distantly generated tsunami is normally at least several hours, but a local earthquake might give only a few minutes warning.

For an interesting couple of hours, visit the Tsunami Museum in Hilo. There is a nominal admission price and plenty of photos and movies of the actual events, in addition to the geological explanations. The mission of the museum is not only to remember history but tsunami awareness. They do feel that they are long over due. I actually talked to a woman who "was there", on her school bus when someone noticed that the water in Hilo Bay had emptied out. Her bus driver headed for the hills and she never got her feet wet. That was in 1946. The only warning at that time was the emptying of the bay prior to the first wave. There is always more than one wave.

We get Tsunami warnings- nothing has happened though. The truth is- when the big one comes you may have no warning. If you see the water suck out off the beach, run like he##. I've seen this subject on the Discovery Channel a lot too. I guess you just can't worry about it.

The phone books have maps in the front that show the expected inundation areas so you can see where to go to escape. There's also sirens/horns like the tornado warning systems here. p.

Well, x, here is a piece from a website about volcanos http://volcano.und.nodak.edu/vwdocs/...img_tiede.html that suggests that the Canary Islands are quite active volcanically : Pico de Teide (28.3N, 16.6W) is the third largest volcano on Earth. ... The most recent eruption was on the northwest flank of the volcano in 1909. OK this volcano is on Tenerife and not La Palma, but turning to La Palma: La Palma has seven historic eruptions, the most recent in 1971 from the Teneguia vent.