Can a volcano eruption on a Spanish island cause a tsunami in New York?

When the Cumbre Vieja volcano began to erupt in September 2021, some experts feared that the lava moving over the Spanish Canary Island would cause a global effect as soon as it reached the water. How can a volcano in one place cause a tsunami in other parts of the world?

What if the fire demon on the island was followed by a tsunami that devastated several places in Spain, Africa and America, reaching thousands of miles from its coast

Some experts claim that the possibility exists of a tsunami reaching the United States and specifically affecting New York. This hypothesis is based on the way the lava is sliding down from mount Cumbre Vieja.

The volcano's material moved over the island towards the deep sea, while hardening in the process. Hypothetically, the clash of the mass into the ocean could make a deep impact with repercussions on other coastlines.

Professor Steven Ward from the Institute of Geophysics and Planetary Physics at the University of California claims that this movement - which would basically be like a stone falling onto a water surface - could lead to a tsunami with dire consequences for the east coast of the United States.

While this scenario is considered feasible, scholars are not convinced that its probable. For this scenario to become reality, the Cumbre Vieja fracture would have to be nearly vertical, extending for tens of kilometers across the island, and several kilometers deep.

Volcanologist Stephen Grill established in 2019 that if a 450 cubic km fragment of the Cumbre Vieja volcano were to slide into the Atlantic Ocean, there would be chances of a mega-tsunami. In fact, the New York City Council has included this risk into its agenda for threats of natural phenomena, established in 2018.

If a megatsunami would occur, it would devastate several areas of the Spanish, Portuguese and African coast in a matter of minutes.

After that, it would take about 7 hours for the tsunami to reach the east coast of the United States.

Luckily, at least for the moment, this specific, dangerous fracture of the Cumbre Vieja has not been observed. It appears, therefore, that the tsunami theory is not in order. The circumstances it requires simply do not exist.

In fact, some volcanologists have rejected this option right away. The Vulcanological Institute of the Canary Islands (INVOLCAN) declares that this hypothesis is very unlikely to become reality.

INVOLCAN experts have been at the foot of the volcano from the first moment. On the basis of first-hand data, they claim that the disastrous scenario is only possible when a large earthquake is combined with an eruption of a greater force than the one that occurred now.

Another option would be for the volcano to reach its natural growth, which they estimate is 1,000 meters (3,280 feet) more than it is now. It would take mount Cumbre Vieja about 40,000 years to reach this point.

Some experts say that social media and their users are the culprits for spreading alarming information that is still far from the current reality. Some even call the suggestion of a tsunami in New York sensationalist.

(Image: still from the movie 'The Day After Tomorrow', 2004)

The Spanish College of Geologists points out that the magma output from the volcano will not last beyond a month.

What does seem to be affected forever is the surface of the island. La Palma will increase significantly thanks to the magma spreading beyond its shores. In addition, the morphology of the affected terrain will be modified forever, thanks to the cones and cracks that were opened by the eruption.

Obviously, the houses that were engulfed by lava will not be recovered either. The rivers of magma have a temperature of more than 1,000 degrees Celsius (1832 Fahrenheit), so it's impossible that anything inside or outside the houses has survived.