Image source: Zazzle
I couldn’t resist quoting this excerpt from a Register article about Tsunamis:
“Geologists have been warning for years about one event that could wash away the entire US Eastern seaboard.
When the Cumbre Vieja volcanic mountain on the Canary Islands last erupted in 1949, a local geologist found it had cracked, with the western face (estimated to be made up of 500 cubic kilometers of rock) sliding down two meters towards the Atlantic Ocean. The islands are very volcanically active and the last eruption occurred in 1971.
In a worst-case scenario, the entire side of the volcano could slide into the sea. That amount of rock hitting the ocean would generate a kilometer-tall tsunami that would still be 50 meters high when it hit the US coastline, with the wave fanning out to disrupt Western Europe as well.