Volcanic eruption in La Palma unlikely to create tsunami
The Claim: Experts Predict La Palma Eruption Will Create Tsunami That Reaches The United States
A decades-old theory has resurfaced online after a volcanic eruption on a Spanish island caught the world’s attention.
On the island of La Palma, in the Canary Islands, a volcano erupted on the afternoon of September 19 after a week-long build-up of seismic activity.
A few days later, lava continued to flow through the four mouths of the volcano towards the west coast of the island. By September 20, he had already forced the evacuation and relocation of more than 5,000 residents.
As the latest developments are shared online, many social media users also share a long-held theory that the rash could cause a tsunami that would reach the east coast of the United States.
“The things I read, they expect it to explode and a piece of land slip into the ocean and cause a tsunami on the east coast of the United States!” said the post. “They predicted this for years.”
The accompanying image is a map of the eastern part of the United States. The text on it says that a “tsunami 50 meters after the volcanic eruption and the landslide in the Canary Islands puts THIS under water”. Florida, New York, Washington, DC, Boston and parts of southern Texas and Louisiana are among the areas allegedly affected by the tsunami, according to the image.
The image has spread widely on social networks. Another version, posted to Facebook on September 19, racked up more than 800 shares in two days before being deleted.
Nick Knowles, an English TV presenter, also shared a version of the claim on Twitter, where he has nearly 160,000 followers.
While the shared theory exists, social media users present it as if it were a probable scenario or representing some expert consensus.
In reality, it’s a hypothesis that U.S. and Spanish officials debunked, saying the conditions for a tsunami large enough to submerge part of the country’s coastline are extremely unlikely.
Following:Volcano erupts on the Spanish island of La Palma, forcing thousands of evacuations
USA TODAY has reached out to users who shared the image for comment.
Volcanic eruption not large enough to create a tsunami
As of September 21, two days after the first lava blast, the Cumbre Vieja volcanic eruption had covered approximately 254 acres and destroyed 166 buildings, according to the Institute of Volcanology of the Canary Islands, who shared news and analysis on the rash.
The risks of acid rain and toxic clouds remain low, although volcanic ash in the air can pose a risk to islanders.
And there is much less chance of a landslide causing a tsunami large enough to reach the coast of the United States.
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The theory has been around since 2001, when two university professors – Steven Ward of the University of California at Santa Cruz and Simon Day of University College London – published a study on the possibility of a tsunami originating in the Canary Islands later reached American coasts and other parts of the world.
The four-page document said that “during a future” eruption of the Cumbre Vieja volcano, a landslide 150 to 500 cubic kilometers, which could trigger a tsunami with waves between 10 and 25 meters high hitting the North America approximately nine hours after the hypothetical volcanic eruption.
Spanish and American officials, however, rejected the theory.
After announcing the eruption on Twitter on September 19, the US Geological Survey said the tsunami threat remained local, debunk user claims that a so-called “mega-tsunami” is occurring.
On the same day, the United States’ National Tsunami Warning Center posted on Facebook that the eruption posed no tsunami hazard on the east coast.
The island’s volcanological institute assured that extreme conditions would have to occur for the theory to become a reality.
For example, the volcano is expected to grow 1,000 meters above its current height, which the institute told Spain’s national television station Antena 3 that it would take another 40,000 years.
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A “mega-tsunami” could also occur if an “exceptionally high magnitude” earthquake and a high magnitude volcanic eruption were to occur at the same time. These two phenomena combined could lead to a landslide of the Cumbre Vieja flank, which Ward and Day’s theory assumed.
However, neither of these conditions occurred.
The âmega-tsunamiâ theory resurfaces with seismic activity in La Palma
The “mega-tsunami” theory often resurfaces with news of a volcanic eruption or seismic activity in the Canary Islands.
In 2016, the Daily Star, classified by Media Bias Fact Check as a âquestionable sourceâ of information based on its âroutine publication of conspiracy theories,â published an article on the theory. In response, Earth geographer and scientist Dave Petley debunked the theory on his blog, “The Landslide Blog”.
Petley, whose research at the University of Sheffield in the UK focuses on landslides, said no volcanic flank collapse in the world had led to a tsunami of the magnitude described by Day and Ward . Additionally, he wrote, submarine deposits from volcanic flank collapses suggest that they do not occur as one large collapse, like the Day and Ward hypothesis.
Rather, they occur in a series of slides, which would make the resulting tsunami “much less significant.”
“It really is time for this event to be presented for what it is, an absolutely extreme scenario based on a combination of very unlikely and unprecedented events,” Petley wrote.
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While the last volcanic eruption in La Palma occurred 30 years before the publication of Ward and Day’s 2001 study, the island is volcanic in nature and seismic activity is often considered normal.
Over the past two decades, there has been extensive seismic activity similar to the small earthquakes seen before the eruption, according to the Spanish National Geographic Institute. This activity was within the normal parameters of the region and “presented no risk to the residents”. Most of the earthquakes recorded are not even felt by locals, as they occur miles below the surface.
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In October 2017, after more than 100 seismic events were recorded in one week in La Palma, the island’s volcanological institute once again debunked the theory.
“Although it has been more than 10 years since this theory, the hypothesis that gave way (to the idea) of a collapse of Cumbre Vieja is still under study,” the institute said, according to the newspaper. online Spanish El Diario.
The institute said the likelihood of a highly explosive eruption occurring at the same time as a large earthquake – which is necessary for the theory to be true – is “extremely remote, according to geological records of this type. event on the island “.
“Cumbre Vieja is stable even under the effects of eruptions similar to those that have occurred over the past tens of thousands of years,” he said.
Our rating: False
Based on our research, we find FALSE the claim that experts predicted that the eruption of La Palma would cause a tsunami that would reach the United States. Spanish and US officials have said the volcanic eruption poses no risk to the United States. Experts have completely debunked it, saying the hypothesis is based on unprecedented events and assumptions of a massive landslide. Experts said such a landslide is extremely unlikely.
Our sources of fact-checking:
- USA TODAY, September 19, a volcano on a Spanish island erupts for the first time in 30 years; lava destroys houses and forces evacuations
- The Guardian, September 20, Canary Islands: 5,000 evacuated as La Palma volcano eruptions continue
- Nick Knowles, September 21 Tweeter (archived)
- Involcan, September 21 Tweeter
- Antena 3, Sep 21 Is there a risk of acid rain and toxic clouds when lava from the volcano of La Palma reaches the sea?
- University of California, June 27, 2001, Cumbre Vieja Volcano – potential collapse and tsunami in La Palma, Canary Islands
- Spanish National Geographical Institute, consulted on September 22, “New seismic activity located in the south of the island of La Palma”
- USGS, September 19 Tweeter
- National Tsunami Warning Center, September 19, post on Facebook
- Antena 3, Sept. 20 Is there a risk of a tsunami after the volcanic eruption of La Palma?
- Media Bias Fact Check, February 7, 2020, Daily Star UK
- Daily Star, July 20, 2019, the dreaded MEGA-TSUNAMI hell as the deadly wave could ‘hit the UK ANYTIME’
- University of Sheffield, accessed September 22, Professor Dave Petley
- The Landslide Blog, September 20, 2016, A Science Story That Won’t Die: The Canary Islands Megatsunami Fear Returns Once Again
- El PaÃs, September 19, TeneguÃa, 1971: this was the last terrestrial volcanic eruption in Spain
- Spanish National Geographical Institute, consulted on September 22, “Earthquake Swarm in the island of La Palma (09-10-2017 and 14-10-2017)”
- El Diario, October 19, 2017, the Involcan assures that the volcanic building of Cumbre Vieja is “stable” and that its landslide is very distant
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