20 September 2016
A science story that just won’t die: the Canary Island Megatsunami scare rears its head once more
Posted by Dave Petley
The Canary Islands Megatsunami scare story
With frightening and depressing regularity the Canary Islands Megatsunami scare story rears its ugly head, to breathless headlines in the popular media. In case you need reminding, this is a scenario that involves a giant landslide from the flanks of the Cumbre Vieja volcano in the Canary Islands, which then generates a vast tsunami that sweeps across the Atlantic Ocean, causing untold devastation across a large area. It has been repeatedly debunked. This story reappeared this weekend in the Daily Star, which might not be considered to be a competitor to the Wall Street Journal, if you know what I mean. Inevitably the story is sensational:
Sigh! And of course it is accompanied with a map of the extent of the tsunami, with annotation to show just how big the impacts would be:
It is hard to know where to start with this as the story has been debunked so many times. So let me try to outline some of the key issues with the Canary Islands Megatsunami scare story:
- The generation of a tsunami on this scale requires a very specific landslide scenario. This is that the flank collapse occurs in a single enormous (we are talking 350 cubic kilometre) event and is extremely rapid. Hypothetically this is possible, but it is not likely. This is like saying that I’m worried that my house will be destroyed by a meteorite. It could of course happen, but it is so vanishingly unlikely that it is not worth considering. It is simply wrong of the newspaper to present an outlier scenario as one that seems likely.
- Studies of submarine volcanic flank collapse deposits suggest that they do not happen as a single coherent block, but instead as a series of slides. The resultant tsunami would be much less significant;
- The concept of “within three years” is a nonsense. Of course it principle could happen within three years – it could indeed happen tomorrow. Why three years? Not five? or 50? Or 3000?
- Most importantly, we know that this volcano, and many others, have undergone massive flank collapse in the past on multiple occasions. We even know that some have generated large local tsunamis. But large tsunamis leave a very distinct sediment footprint on the coast – tsunami deposits are well characterised and mapped, and no self-respecting geologist would miss a large one. And the megatsunami deposit from an event like that shown in the map above would be locally huge and would be present over a vast area. There is no way that such a deposit would be missed. But no such pervasive, recent, continent-scale tsunami deposit has ever been found. This indicates of course that none of the previous flank collapse events has generated a megatsunami on this scale, or even close to it. And I mean none of them – not from the Canary Islands, not from Hawaii, not from anywhere else. So, in some way, the potential flank collapse at Cumbre Vieja has to be fundamentally different from all that have gone before.
- And finally, even if Cumbre Vieja did collapse as hypothesized, the tsunami model described above would have to be right. Personally I find it hard to believe that a tsunami wave that is in effect generated by a point source and that has crossed the mid ocean ridge (and thus encountered comparatively shallow water) could generate a wave over 50 m high along a length of coastline thousands of kilometres long.
So does this mean that Cumbre Vieja can generate a large tsunami? Yes, of course. But is it even remotely likely beyond the local area? Absolutely not, in my view.
And of course aspects of this are silly from a risk perspective:
“Although Florida and the Caribbean would suffer the greatest destruction, with waves up to 164 ft smashing their coastlines, a weaker, but still massively destructive wave, is likely to batter Britain. It is thought thousands of people living in Britain’s southernmost coastal cities and towns, including Cornwall, Devon and Portsmouth, could be wiped out within hours, assuming no effective evacuation.”
“I would argue that they, their political overseers, and we the general public, should worry about the potential impacts of collapse generated tsunamis on a range of coastal nuclear facilities, ranging from power stations through nuclear reprocessing plants to dockyards full of decommissioned nuclear submarines.”
Frankly if a wave 50 metres high has just struck the entirety of the Eastern Seaboard of the USA and Canada, the Caribbean and the eastern coasts of Latin America; and a wave 100 m high has struck the western coast of Africa; and a wave has just wiped out western coasts of France, Portugal, Ireland, and the UK, all within six hours, then a wave 6 m high hitting Hinckley Point is going to be a pretty small part of the overall equation.
It really is time that this event was presented for what it is, which is an absolutely extreme scenario based on a very highly unlikely combination of events that is without precedent. There are lots of credible hazard scenarios that deserve our attention; this one does not.
You’re absolutely right! This whole mega tsunami bull has been around for over 20 years and it just won’t die! The media isn’t interested in science. They are interested in sensationalism and hysteria. That’s one of the reasons we’ve got this whole hysterical overreaction to a mild cold (covid 19 flu) at the moment. I’m still waiting to get swine flu from 2009 for goodness’ sake – the media was hysterical then as well!
Shame on you.
I agree, it’s all about scaring the public. These people should all be ashamed of themselves.
If you truly think that Covid is a mild case of the flu, you’re pretty much worthless.
I can agree about the tsunami fact with you, but covid… shut up Karen, I’ve lost 4 family members that had seasonal flu once in a while like everyone else, but covid took them from me!
October 21, 2021. La Plama is in 34 days of eruption. Now what do you think? Pre-conditioning for the real deal people.
Your “mild flu” has killed over 4.5 MILLION people worldwide. The media didn’t kill my aunt, COVID did. COVID is real in the here and now, it is not an event that may never take place scientists are debating like a tsunami. The media did not invent COVID nor can they stop it.
The media could stop lying about effective treatments when a number of medical articles show Ivermectin, for example, to be effective. It could also stop spreading hysteria when the recovery rate is 99.7% and the .3% typically involves co-morbidities. I just got over a case of covid and I now have strong natural immunity. Fresh air, exercise, vitamin C, low stress… immune system.
Your limited personal experience means nothing. You’re hopelessly uninformed.
You are completely incorrect. The media not only hyped the virus, but lied about it. What made it worse is the wrong treatment, being remdesivir, which caused pulmonary edema, killing many! Registered Nurse and I watched it happen. Meanwhile other treatments were banned, even though they proved to work!!! Prizer wouldn’t have made any money, through! The data is there research it. Also, quit being a psychopath, worry about the world ending. Go live!
And childhood hunger kills approximately 9 million people every year. So where is the need and helping those people?
WTF has sneezing n colds/flu/COVID or whatever got to do with bloody tsunami waves??? Is the island going to cough it’s western flank off? Should we be injecting mountains with COVID vaccines??
I think not…in my most humblest opinion I believe there might be a threat from Cumbre Vieja.. if as the guy above said the scenario is right but we’re looking at 6 or 7 randomly occurring things that just have to happen exactly in the right way, at the right time for this scenario to play out as the newspaper suggested.. im not saying it will happen, im just not saying it won’t either.. history has told us on several occasions in the last billion or so years that this earth and the solar system around it could quite easily have the power to wipe us completely from this plain of existence and all trace of us.. I could list 10 scenarios now that could destroy us all, and a virus is up there with the rest, earthquakes, tsunami’s, supervolcanoes and ourselves for that matter (if you look at nuclear weapons figures world wide there’s enough to destroy earth several times over..) and that’s just on earth..asteroids, comets, coronal mass ejections, solar mega flares, gamma ray bursts wandering planets/black holes/stars hell even just being in space without the right gear and ur dead…
I’m truly sorry you lost your Aunt, Katie, and I do think whomever is responsible (person/persons/governments) for this COVID bullshit should be publicly tortured and executed by the family’s of those who died for they’re greed and stupidity for making an already dangerous virus into something that could potentially mutate and become resist to any forms of antibiotic or medicine.. which would mean a lot more of us would perish.. and for what? To line the fucking pockets of big pharma/military industrial complex/elitists around the globe..
I for one think the world we live in is a fukin disaster waiting to happen..INTERSTELLAR had it right..
“7 Billion People Living On Earth, 7 Billion People Who Want To Have It All”
in a world where having it all seems to take president over feeding the poor and helping those who can’t help themselves.. it’s only a matter of time before Mother Nature decides to upset the apple cart.. our short “ownership” of earth will be put purely in perspective when we’re faced with something No one has ever seen before and there’s no scientist or expert on the land that can help.. be it a super-volcanic winter, solar flare frying the globes electrical systems, or even something as mundane as a scientific experiment gone wrong…I.e the releasing of a potentially lethal pathogen or a cock up when trying to perfect nuclear fusion.. ONE DAY OUR IGNORANCE OF THE WORLD THAT KEEPS US ALIVE WILL CATCH UP WITH US..AND ONLY THEN WILL WE SEE HOW BLIND WE AS A SPECIES HAVE ACTUALLY BECOME.
I loved every bit of it. Beautiful.
Bravo man – truer words have not been spoken
Soooo with the island sinking today we shouldn’t worry about the tsunami on the Atlantic coast?
Do you have some information or a link to a reliable source that states that the island of La Palma is sinking? I haven’t found anything under this heading.
The problem, here, is it’s all conjecture. Science does support the possibility of a mega tsunami. Currently, Facebook is banning discussion, using this by it’s fact checkers to censor actual facts. It’s all quite sad, now.
Whenever Facebook censors something I actually have to give it more attention because they do not like the truth out there or people to be prepared.
With a little assistance from a few nukes I can see This easily manifesting itself, it’s not in every movie for nothing….
CANARY LANDSLIDES ANOTHER THEORY:::mythology tell the story of mount atlas and its 7 doughters. as historical reports claim and the remnants in the bay of agadir maroc show, the 7 todays canary islands are secondary (Shield) volcanoes those had formed already around the edge of what the romans refer as “mount Atlas -in their believe once the “highest mountain on earth” . When this previous supervolcano previously ,attached as a peninsula to the coast of maroc as all of the original supervolcanes on earth once many around 20- 30.000 BC exploded, the explosion caused the big shock and landslide that formally stripped of the islands from the fragile volcanic material that was of all around the today canary islands, the big rock missing in the canadas del teide was swept there by another megatsunami. the earth mantle was once generally is not more as hot it once was so explosions of such are scale likely shoul never occur again . only solar proton events have still the potential temprarely to heat up the earth mantle again so that magma is pressed upwards through its hot spots.
well, this was entertaining….and i’m sorry, but who in the world would take ivermectin for covid?? it’s for parasites, not viruses…..and unless i’m going to get the same worms/parasites that can affect my dogs, i’m not going to take it…. just because a bullet in your head will stop your migraine doesn’t make it a good idea…..
SPANISH geologists same as german think they just can judge all like the inquisition from their higher position without talking and without using their as they claim better arguments and expert knowledge but rather due to what they believe they ignore facts that have nothing to do with that tsunami issue and just dislike and delete others opinions . one feels lika a dummie at the moment tha lava burns down houses and the eruption semms still to intensify
sorry i just saw my previous comment still awaits moderation. no spanish geologist hat in the past alwas the right judgment but science shoul not be autoritaire but open to everyone thanks i love the canaries unfortunately i cant live there anymore due to pension restrictions by the german authorities i hope the day will come when everybody is fee again.greets from munich
I don’t know… I do believe we should keep an eye on this. The eruption continues to have earthquakes that’s the scary part of it all. It’s one thing for it to blow like Mt. St Helen and another thing for it to continue to have earthquakes during the eruption.
I will not approve any more comments about Covid-19. This is a blog about landslides, not a place to promote conspiracy theories about the pandemic.
Dave Petley, owner, The Landslide Blog
Any idea of the local risk of a small tsunami?
Would you avoid going to Tenerife on holidays?
Thanks in advance.
[The likelihood of a failure is so small that I would not worry about going to Tenerife. The slope is being monitored. It is likely that a failure would show extensive precursory activity, which would allow measures to be taken to protect the population. At the moment there are no indications of the development of a slope failure. D.]
Today we had a very big earthquake 4.8 followed by many small ones, a new collapse of the volcano and a landslide into the sea seems more and more likely, plus now they are confused as they are speaking of a 10 cm elevation they even said on news that they would re measure. Earthquakes are more frequent and more intense. Is this not
It’s not just La Palma, it’s Tenerife too. The historical flank collapse on Tenerife is north facing. There is definitely a chance of a combination simultaneous earthquake, landside and explosive eruption, all heading North. See “Multi-stage volcanic island flank collapses with coeval explosive caldera-forming eruptions” https://www.nature.com/articles/s41598-018-19285-2
But also with regards to a 16ft wave travelling at 250mph from La Palma up the Irish Sea with only a few hours warning:
How are we going to evacuate 10,000 workers from Sellafield (Europe’s most dangerous nuclear site)?
How are we going to return them safely when the site is under water? There’s no sea wall, the buildings look like tin shacks and they’re all at sea-level.
What are we going to do when the 100,000 tonnes of fire prone irradiated graphite soon to be stored there (on the surface, in cooling tanks) combusts and starts raining cobalt-60 into Manchester’s water supply while making Cumbria and Tyneside uninhabitable?
Interested in your thoughts. Thanks.
[The paper you cite says the following:
“Volcanic island flank collapses can also produce destructive tsunamis. This and other Canary Island flank collapses were multistage, dividing the landslide mass among numerous staggered failures, resulting in reduced tsunami wave amplitudes compared to equivalent single-block subaerial failures, because the volume is the primary control on tsunami amplitude. Modelling of landslide-tsunamis suggest that time lags of at least greater than 20–50 seconds between successive stages of collapse removes effects of wave inference that would otherwise cause increased tsunami wave amplitudes. Our study suggests that time lags on the order of days likely exist between the individual stages of last three significant failures from the northern flank of Tenerife, and as a result the tsunami waves were likely discrete without interference and thus had lower comparative amplitudes.”
So the likelihood of 16 ft wave in the Irish Sea is not high. D.]
Thank you for your response.
There are models showing minimal likelihood of serious waves from La Palma affecting the UK, but taking the landslide at Mount Saint Helens as a model for the north face of Tenerife, could this landslide alone cause a catastrophic wave? Is the Mount St Helens landside a reasonable estimate for the general force?
Are there any models of general tsunamis entering the Irish Sea? Given the dynamics of the Irish channel, do we know the limits to avoid serious flooding?
Given the multiple possible sources for a tsunami wave affecting the Irish Sea, is it possible to estimate the likelihood of flooding at sea level on the Cumbrian coast over the next 100 years?
This video from AGU shows a model of the most recent landslide and resulting tsunami on Tenerife from 180,000 years ago:
The largest portion of that energy is heading in a direct straight line into the Irish Sea 3000km away.
“Mount St. Helens remained dormant from its last period of activity in the 1840s and 1850s until March 1980.”
We have about 3 months warning between dormant and landslides? Is that long enough to build a 20m sea wall around Sellafield?
Sweet Ocean front property.
The problem we have here is that, yes, a 150 meter tall wave is the worst possibility – so very unlikely – but it does not have to be the worst to be deadly to more people than any sane human could dismiss.
However, what is the likelihood of half the size because not everything is perfectly the worse? Even at half the size, the Cumbre Vieja tsunami hazard still will be one of the worst natural disasters for western European coastal nation and the Eastern US and Canada in written history. A half the sized Cumbre Vieja tsunami still takes out Charleston, SC, Washington DC, New York City NY and Halifax NS. In Ireland half the size still flattens, Dingle, Waterville, Kenmar, and Bantry. In Spain Huelva and south of Seville; and in Portugal say goodbye to Lisbon.
And, even at a 1/4 of the size it still is hundreds of billions in monetary losses and millions is peoples lives in many the same cities above. The worst cases scenarios is unlikely; but half or a quarter is still more than the Caribbean, US, and Candida could take.