The largest tsunami ever recorded struck Lituya Bay in 1958. (Image Credit: NASA Earth Observatory)
In 1958, a huge landslide caused 90 million tons of rock to slam into Alaska’s Lituya Bay. This impact produced a tsunami with a wave height of over 500 meters, the largest tsunami wave recorded to date. The event’s effects were so profound that it changed the landscape. With NASA’s satellite technology, we can see the changes from space today.
NASA and other agencies used satellite technology to observe the long-term impact of this massive tsunami. It may have lasted a few minutes, but we can still see the effects on the landscape more than 60 years later, thanks to high-resolution optical imaging from satellites like Landsat.
The trimline, a distinct boundary marking the area where the tsunami scoured away vegetation and soil from the hillsides around the bay, remains visible. This trimline appears in false color Landsat imagery (Landsat 8, bands 7-5-3) as a light-colored band along the shore, where younger forests grew, contrasting with the darker green undisturbed forest further inland. NASA’s Landsat 8 and 9, both equipped with the Operational Land Imager (OLI), use visible and near-infrared spectral bands at 30-meter resolution to capture the differences in vegetation recovery.
By analyzing these satellite images, researchers can confirm that the damage from the megatsunami is discernible today. NASA also uses geographic information systems (GIS) and remote sensing software like QGIS and ENVI to layer and interpret the images. This results in a full, clear picture of how a major tsunami event forever altered a stretch of the Alaskan coast.
Now, if they could only use that data to make a visual simulation of the event. Tell me you wouldn’t want to see that…
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