From San Francisco, at a meeting of the American Geophysical Union
Pieces of moss buried in debris deposits along the Norwegian coast have enabled geologists to better peg the date of an ancient tsunami and the immense underwater landslide that triggered it. Carbon dating of the newly unearthed moss suggests that the landslide occurred about 8,100 years ago.
Sometime after the end of the last ice age, the largest landslide known to geologists took place off the coast of Norway. Called the Storegga slide, this slump of seafloor sediments included about 3,000 cubic kilometers of material. That's enough mud to cover the entire United States to a depth of about 30 centimeters, says Stein Bondevik, a geologist at the University of Tromsø in Norway.
The tsunami created by the slide scoured coastal sites in Norway, England, Scotland, and Greenland, in some places to heights of 20 meters above sea level. Scientists have previously used carbon dating of see