|Landsat image of Lituya Bay |
as presented in the Geology.com article referenced in the text
|Lituya Bay and the elevations of the wave|
from Geology.com based on Miller's USGS PP (1960)
The impact from this rockfall on the water generated a huge splash wave within Gilbert Inlet. The impact of this rock mass disturbed not only the water, but also the sediments under it, and also tore off part of the toe of Lituya Glacier, causing drainage of a subglacial lake. The "tsunami height" of 1720 m is taken from the height that "this impact splash" reached on the ridge at the southwest side of Gilbert Inlet, in close proximity to the point of impact. As the splash traveled out into Lituya Bay, it quickly decayed to less than 200 feet high, and maintained a height on the order of 100 feet throughout much of its passage down the Bay.
Remembering that the word "tsunami" means "harbor wave," this wave in Lituya Bay qualifies as a "harbor wave." It is may be the best studied example of the near-field dynamics of a big splash. Astrogeologists would also call it "impact ejecta." Further technical references are given at the end of this article.
**An example this wave being called a tsunami is the BBC Nature program Mega Tsunami-Alaskan Super Wave--Amazing Survival."