What if a single rock the size of the rockfall that triggered the world's tallest tsunami were to free-fall 3,000 feet directly onto land and not into water?
On the night of July 9, 1958, an earthquake along the Fairweather Fault in the Alaska Panhandle loosened about 40 million cubic yards (30.6 million cubic meters) of rock high above the northeastern shore of Lituya Bay. This mass of rock plunged from an altitude of approximately 3000 feet (914 meters) down into the waters of Gilbert Inlet (see map below). The impact force of the rockfall generated a local tsunami that crashed against the southwest shoreline of Gilbert Inlet.
The wave hit with such power that it swept completely over the spur of land that separates Gilbert Inlet from the main body of Lituya Bay. The wave then continued down the entire length of Lituya Bay, over La Chaussee Spit and into the Gulf of Alaska. The force of the wave removed all trees and vegetation from elevations as high as 1720 feet (524 meters) above sea level. Millions of trees were uprooted and swept away by the wave. This is the highest wave that has ever been known.
Quote taken from: https://geology.com/records/biggest-tsunami.shtml
What if this rockfall had happened over land, but as a single huge 40 million cubic yard rock falling straight down?
- Would the rock have created a seismic event of its own (if so, how large)?
- Would the rock have created a crater?