Alaska / Modern science
The Lituya Bay giant wave
In 1958, an earthquake sent rock into a narrow Alaskan inlet. The resulting wave stripped vegetation from a slope more than 500 metres above the water.
The high-water mark records the violent displacement of a confined body of water. Its scale changed how geologists understood waves produced by landslides.
A CLOSER LOOK
On July 9, 1958, a magnitude 7.8 earthquake ruptured about 125 miles of the Fairweather Fault. At the head of Lituya Bay, rock fell into Gilbert Inlet and displaced the water below. The narrow geometry of the inlet focused the first surge against the opposite slope.
The clearest measurement came from the trimline left on the hillside. Trees and soil were removed to an elevation of about 1,720 feet, or 524 metres, above sea level. This figure describes the maximum runup on land. It does not mean a 1,720-foot wall of water traveled the full length of the bay.
A wave more than 100 feet high moved down the bay. Three fishing boats were present. Two rode through the event and escaped; the third was lost with two people aboard. The earthquake caused five deaths in the region, all on the water.
Geologist Don J. Miller had documented evidence of earlier giant waves in Lituya Bay before 1958. His fieldwork after the event connected the new trimline, eyewitness accounts, and the rockfall scar. The case helped establish landslide-generated tsunamis as a distinct hazard in steep coastal inlets. Modern models refine the sequence, while the measured landscape remains the essential record.
FOLLOW THE EVIDENCE
Alaska Earthquake Center60 years ago: The 1958 earthquake and Lituya Bay megatsunamiUniversity of Alaska Fairbanks Geophysical InstituteThe giant wave of Lituya BayNOAA Office of Coast SurveyThe latest expedition in Lituya BayOriginal explanation based on the sources above. Images carry their own reuse terms.