||La Palma Tsunami
The mega-hyped tidal wave story
|Visit La Palma|
|La Palma photographs and tourist information|
| ..... more information|
|The list of scientific organisation with contra-evidence now includes:|
|*||Canarian Volcanic Institute|
|*||Southampton Oceanography Centre|
|*||The Tsunami Society|
|*||Charles L. Mader, Tsunami expert|
| .... more information|
|The original arguments:|
|The proposed theory is basically that if volcanic activity1 occurs on a large enough scale water trapped2 in the volcanic rocks will be super-heated under pressure3 and will suddenly explode4 with such force that a huge chunk5 of La Palma will suddenly and very very rapidly6 drop into the sea and cause a Mega-Tsunami7 that would grow in size and cause damage8 when it reaches Florida.|
|Point 1: volcanic activity|
|'La Palma is the most active volcano in the Canary Islands'.|
It sounds dangerous doesn't it. It isn't. In comparison with Japan, Hawaii and Italy the La Palma Cumbre Vieja volcano is almost dead.
When you talk to people about active volcanoes they immediately image a large pointed mountain with a crater in the top with red hot lava, steam, smoke, boiling mud pools, and they imagine that new ash and smoke comes out every few days.
Lets get this into perspective. There is no big pointed mountain with a smoking crater on La Palma. People point to the Caldera de Taburiente as if it is a volcano, but it isn't. It was formed by a volcano but is not a volcanic crater. The hole in the middle was formed over the centuries by erosion and not by a volcano or a sudden massive collapse. It is the worlds largest erosion crater and well worth a visit.
The volcanic cones on La Palma are small and completely dead. It is a spectacular landscape but there is no steam, no smoke, no bubbling pools and no red hot lava. There used to be one very small area where the earth felt warm but even that has cooled down now.
Some reports refer to La Palma, Mount St. Helens and Krakatoa in one breath. This is disinformation at its worst. There is no comparison between these volcanoes. It's like comparing lions, tigers and hamsters ... they all have teeth so they must be dangerous man-eaters 'Buy hamster-mauling insurance before its too late!' 'Invest in hamster hazard-warning systems now!'.
The original report states that all volcanoes previous to 1949 have not caused any longitudinal rift in La Palma. The 1949 appears to have caused a 4km long scratch at the surface. Proof that it is 2km deep is not in evidence.
La Palma is constantly monitored and no seismological movements have been registered on the Cumbre Vieja volcano since 1949.
|Points 2 and 3 : trapped water under pressure|
|There is lots of water in the rocks of La Palma, just as there is in most of the world's porous rocks. This is not unusual, it is perfectly normal and most of the world gets its water from water contained in rocks. No problem.|
For the 'exploding super-heated water under pressure theory' to be realistic there would have to be 2 parallel, solid vertical walls of impermeable granite or basalt both extending for 25km along the length of La Palma to a depth of at least 2km and without any breaks. To enable the required pressure to build up there would have to be a solid layer on top of these two 25km walls to keep the pressure in. Without all these conditions there is no possibility of a pressure build-up. The rocks on La Palma are very porous; they allow the water to get in and out at will.
Without the 2 walls and the solid roof it would be like boiling water in a frying pan.
|Point 4: explode|
|Exploding volcanoes are the basis for several Hollywood movies. In reality there have been very few occurrences. This is because a special type of magma (underground molten lava) and millennia long subterranean and superficial build up of rock formations is required to develop the circumstances in which a volcano will catastrophically explode.|
These conditions do not and will not exist on La Palma. La Palma volcanoes cannot explode.
|Points 5 and 6: huge chunk, suddenly and very very rapidly falling into the sea|
|This is where reality and statistics suddenly start to take giant leaps away from each other. The researchers problem was, of course, to figure out how much water would need to be moved to create damage (in the future) and panic (now) in Florida. Enough panic to sell lots of insurance and generate investment in further research projects on which they are dependent.|
The answer is that it would need a very large amount of rock to break off La Palma and slide into the sea with enormous speeds and as one great big block. Only if this happens would there be a splash big enough to reach America.
The researchers point to 2 large piles of rubble under the sea next to La Palma as evidence that this has happened before. The problem is that the rubble only proves that rock from La Palma has fallen into the sea. It does not provide evidence that all the rock fell into the sea as a single massive block and cause a tsunami. It is much more likely that this pile of rubble is caused by continual natural erosion as occurs all over the world. The researchers who have spent 20 years studying these rocks were not consulted on the Mega-Tsunami theory. After seeing the documentary they issued a statement stating that a single event collapse of the west side of La Palma was very unlikely and the physical evidence points to a series of small landslides over a very long period of time.
So where is the evidence for the boundaries of the rock slide used in the mathematical model??
Having shown that there is a fault line on the west side of the Cumbre Vieja you would expect that this would be the line used in the model. WRONG. The line used in the model is situated 2 to 3km to the EAST, on the opposite side of the Cumbre Vieja. Why? .. otherwise the splash wouldn't be big enough?
Then there are the Northern and Southern extents of block. Where are they? Firstly the physical evidence on the ground is of a 4km long split. The claim is that this split is the upper edge of a fault line extending 2km under the ground. No evidence has been presented to support this theory. It could just as easily be a scratch on the surface extending just a few meters below the surface. But in any case the length of the split used in the model is 25km. WHY? There is evidence for 4km so they added 21 extra kilometres for which there is no evidence what so ever? The answer is getting boring ... because without this unjustified exaggeration the boats in the harbour on the next island wouldn't even start to rock.
How deep would the lower boundary of the block be? In the original report it is stated that there is no physical evidence by which to estimate the base of the block. Despite this lack of evidence a guess of 2 to 3km below the surface was used in the mathematical model.
And then there is the question of the speed of the block. If this is not fast enough there will be no tsunami. A speed of 100 meters per second was used. A comment in the report shows that this cannot occur when a rock block slides over rocks. There has to be a lubricating substance at the base of the block otherwise nothing happens!! The suggestions are mud (at 2-3km under the ground?), water pressure (in the open lava on La Palma?) or heat from horizontal dykes which would have to be red hot, several meters thick and suddenly push their way through solid rock at the correct downward angle over a length of 25km, and travel 10km towards the sea almost instantaneously.
|Point 7: cause a Mega-Tsunami|
|This assumption is very debatable. The evidence that tsunamis are caused by landslides is limited. The evidence of destructive tsunamis is only present when the landslide occurs in a bay or enclosed channel between landmasses. La Palma is not in a bay. La Palma has no other landmass between it and Brazil/Caribbean/Eastern USA, there is no enclosed space.|
The 'classic' mega-tsunami occurred in 1958 in Lituya Bay, Alaska. There are 3 theories about how it was caused, one of which is an unproven catastrophic landslide theory. The tsunami caused much damage in the narrow inlet but did not travel great distances and caused only local damage.
Other recorded tsunamis were caused by earthquakes and not landslides. Comparisons of La Palma with Krakatoa and Mount St.Helens are incorrect and (deliberately?) misleading.
Suggestions that the strange position of boulders and chevrons in the Bahamas is related to the collapse of El Hierro in the Canary islands are pure speculation and are NOT based on scientific research. In fact the author of the original report suggested in 2001 that geologists should start looking for evidence of the effects of a possible tsunami on the East coast of America, Brazil and the Bahamas, which is a sure indication that no such evidence existed at that time. Even mentioning a possible link can only be described as deliberately misleading. Geologists in the Bahamas insist that the chevrons could not have been caused by a tsunami.
|Point 8: damage in Florida|
|A tsunami created in La Palma will not reach Florida. Even the 20 meter high Lisbon earthquake tsunami was hardly measurable when it reached the other side of the Atlantic.|
The algorithm used to prove that it will is based on evidence from linear under-sea earthquakes and is not valid for single-point events like a landslide on La Palma. The volume of water which might be displaced will not travel as a straight line which inherently maintains its height and volume. It will travel as ripples which rapidly dissipate to insignificant levels within a very short distance.
Example: If the amount of water is displaced is 10 meters high and travels as part of a massive linear wave then that mass will remain supported by the block next to it and retain its height over great distances. The base area of that water will remain roughly constant. In a single-point the wave radiates out over 180 degrees and the same amount of water will be spread very thinly over a wide area.
Imagine filling a 10 metre long and 10cm high balloon with water and pushing it along the road. Provided the balloon doesn't burst the balloon will stay 10cm high until it meets an obstacle. That is what happens in an earthquake-induced tsunami. In a landslide-induced tsunami the ends of the balloon would go off at (say) 90degree angles. For every meter the balloon goes forward it will be stretched in length and the height of the balloon would be reduced very quickly.
|The evidence for a total and sudden collapse of the western flank of La Palma is not based on provable facts. The chance of a total failure of the dimensions suggested is negligible. The probability that anything will happen in the next 1000 years is a very small. |
The La Palma Tsunami story is just that, a nice horror story to frighten people into buying insurance and to frighten governments into investing in hazard research and hazard warning systems.
I believe it to be speculation and scaremongering for commercial purposes.