Weather History - Furure Storms

80-Ft.-High Tsunami, Atlantic Coast
Coast Buster

Click to enlarge A massive collapse of Cumbre Vieja in the Canary Islands would cause a tsunami to radiate all the way across the Atlantic Ocean to the East Coast. PHOTOGRAPH BY J. SCHWAKE/ALAMY

Cumbre Vieja, the most active volcano in the Canary Islands, lurches as a violent earthquake wracks its upper slopes. A third of the mountain breaks away and plunges into the Atlantic Ocean, pushing up a dome of water nearly 3000 ft. high. They don't yet know it, but tens of millions of Americans from Key West, Fla., to South Lubec, Maine, have just 9 hours to escape with their lives.

Click to enlarge The tsunami's probable trajectory within 5 hours of the collapse of Cumbre Vieja.

The collapse of Cumbre Vieja unleashes a train of enormous waves traveling at jetliner speed. The first slam into nearby islands, then the African mainland. By the time they reach the East Coast of North America, the waves are up to 80 ft. high, and in low-lying areas, sweep several miles inland.

When tsunamis strike the United States, it is usually Hawaii or Alaska that take the hit. But topography and population density put the East Coast

Click to enlarge The tsunami's potential range of destruction 9 hours after the collapse of Cumbre Vieja.

in a special risk category. “More Easterners are exposed to potential tsunamis--from the Canary Islands or the Cape Verde Islands--than the people on the West Coast, which has a steep coastline and few lowlands,” says Steven Ward, a geophysicist at the University of California, Santa Cruz. A Cumbre Vieja eruption in 1949 opened a mile-long, 20-ft.-deep fissure near the crest, forcing the volcano's western face to slump several feet. A 1971 eruption didn't budge it.

Marine geologists at Southampton Oceanography Center in Great Britain have a different take. They conclude the volcano would collapse in stages--

at worst threatening nearby islands. Ward calculates only a 5 percent chance Cumbre Vieja will trigger a tsunami in a given century, but that when it does a chunk of earth 15 miles long, 9 miles wide and nearly 1 mile thick will plunge into the sea--a landslide 250 times larger than the collapse of Mount St. Helens.


Coast Guard: Dangerous Rescues - Preview





RS