Could a massive tsunami, like the one that hit Japan in 2011 after a powerful earthquake, happen in the U.S.? According to an article in The New York Times, scientists are getting closer to finding out.

Scientists have learned that the waves from that tsunami were as large as they were because the part of the seafloor along the fault moved as much as 55 yards to the east in the earthquake, displacing an enormous amount of water, the article states.

That degree of movement is the largest ever measured for an earthquake, says the article. What makes this more surprising is that the earthquake occurred in a subduction zone, where one of the planet's tectonic plates dives beneath another. It was thought that the largest slip would occur at greater depths, and that shallower parts of the fault, nearer the seafloor, would move less, according to the article.