The name of these islands derives not from the yellow bird of the same name, but from the Latin word for dogs, Canaria. The islands are volcanic, overlying a mantle hotspot. Pico del Teide on Tenerife is the third largest volcano on Earth, rising more than 12,000 ft (3,700 m) above sea level, or almost 23,000 ft (7,000 m) from the sea floor. It last erupted in 1909. Teide’s slopes are unstable, and there is evidence that huge landslides have occurred in the past. There is also a risk that volcanic activity or earth tremors could cause part of La Palma island to slip into the sea, resulting in an enormous tsunami. Such an event would threaten the coasts of the north Atlantic, including heavily populated parts of North America, with inundation.