'Megatsunami' could reach US East Coast in just hours after catastrophic volcano collapse in Spain, scientist claims

A catastrophic volcano collapse could send a 'megatsunami' toward the US East Coast within hours, according to a scientist.The warning comes from volcanologist Professor Bill McGuire, who has been monitoring Cumbre Vieja, a vast volcanic ridge stretching roughly 12 miles and towering nearly 6,400 feet above sea level on La Palma, one of Spain’s Canary Islands off northwest Africa. A worst-case computer model outlined in McGuire’s BBC Science Focus article suggests waves roughly 65 feet high could reach Florida just nine hours after the collapse.The scenario involves a massive section of the volcano’s western flank breaking away and plunging into the Atlantic, displacing an enormous volume of seawater.Near the collapse site, the model predicted an initial dome of water almost 3,300 feet high, which would fall back to generate waves that overwhelm La Palma and neighboring islands before spreading across the ocean. Other estimates suggested waves reaching the US East Coast could be around half the height predicted for Florida, at approximately 33 feet.While scientists continue to debate the scale of the destruction such a tsunami could cause, McGuire's worst-case model illustrates the potentially catastrophic consequences for the US East Coast. 'The bottom line is that we just can’t say where the next volcanic tsunami will happen, nor how big it will be, but happen it will,' McGuire said. The warning comes from volcanologist Professor Bill McGuire, who has been monitoring Cumbre Vieja on La Palma, one of Spain's Canary Islands off northwest AfricaConcern centers on the volcano’s steep western flank, which McGuire said became partly detached during an eruption in 1949. 'During the 1990s, my research team confirmed that this huge mass of rock, adding up to [hundreds of billions of cubic yards] in volume, was creeping slowly seawards, at perhaps [0.4 to 0.8 inches] a year,' he wrote for Science Focus.'I expect this part of the flank will eventually crash into the North Atlantic, launching a megatsunami in the process.'McGuire also pointed to huge boulders in the Bahamas that some researchers believe were deposited by ancient tsunamis originating in the Canary Islands.That interpretation would suggest destructive waves can survive an Atlantic crossing, although he acknowledged that the proposed origin of those deposits remains disputed.A flank collapse generates a tsunami by suddenly forcing a huge volume of rock into the water, displacing the sea and sending waves spreading outward from the impact.McGuire explained that a volcano does not have to be erupting for part of it to give way. Gases seeping through the rock can weaken its interior, allowing a section of the flank to break off and become a fast-moving landslide.Evidence of enormous prehistoric waves can also be found around the Canary Islands. A worst-case computer model outlined in McGuire’s BBC Science Focus article suggests waves roughly 65 feet high could reach Florida just nine hours after the collapse. Above is the volcano erupting in 2021 Mega tsunamis can be triggered by events such as landslides or volcanic island collapses (stock image)According to McGuire, ancient tsunami debris has been identified almost 980 feet above sea level, pointing to at least five megatsunamis over the past million years.In the Cape Verde islands, deposits about 900 feet above sea level have been linked to an ancient collapse of Fogo volcano.These deposits offer clues to the destructive power of earlier collapses, although they do not establish how large a future wave reaching America would be.One historical example came in 1792, when earthquakes near Japan’s Unzen volcano triggered a landslide that tore through Shimabara and plunged into Ariake Bay.McGuire described an initial wave roughly 100 feet high, followed by a tsunami that crossed the bay and reflected back toward the town.The landslide and waves together killed around 15,000 people, illustrating how a single collapse can unleash several successive stages of destruction.The danger is illustrated by the December 2018 disaster at Indonesia’s Anak Krakatau volcano, where a collapse sent a tsunami toward nearby coastal communities.According to McGuire’s account, the waves struck in less than 30 minutes, killing more than 400 people and destroying thousands of homes.Volcanic tsunamis can also arrive as a succession of waves, bringing repeated flooding rather than a single surge.The Indonesian disaster demonstrates the destructive potential of a volcanic collapse.