Canary Islands and Atlantic Tsunamis

Abstract

GEOLOGY Recently, giant submarine landslides, including some more than 20 kilometers long, have been recognized around Hawaii. Some slides may be responsible for generating large Pacific Ocean tsunamis. Krastel et al. have now identified a large number of submarine slides in the Canary Islands in the central Atlantic Ocean off the coast of Africa. Like Hawaii, the Canary Islands are volcanic in origin, although the magmas that formed the islands are richer in silica and water than those of Hawaii. The authors used sidescan sonar to map twelve landslides that apparently formed within the past 2 million years, some of which are near the youngest islands. Several of the slides may have volumes approaching 1000 cubic kilometers. The abundance of landslides exceeds that recognized on Hawaii, likely because of the steeper slopes and more varied rocks of the Canary volcanoes. Evidence for past landsides suggests a greater tsunami threat for the Atlantic region than had been realized from previous studies. — BH J. Geophys. Res. 106 , 3977 (2001).