When I was a kid, I read a book by Pearl Buck called The Big Wave. It was a fairly short book that told the story of a tidal wave and its effect on the people of a Japanese village. I was surprised to find that The Big Wave is still in print. It was originally published in 1948. The original version used the prints of Hiroshige and Hokusai, such as you see above.
The reason I bring this all up, is I was reminded of the book by an article in the Boston Globe. The mystery waves in the article aren't tidal waves (now more commonly known as a tsunamis), but they might be rogue waves. "Rogue wave" is a term I hadn't heard before. Here's an explanation.
You can learn more about large waves in either of these books by Ellen J. Prager, Furious Earth: The Science and Nature of Earthquakes, Volcanoes, and Tsunamis [551.2 PRA], or, The Oceans [551.46 PRA].