Rogue waves by the numbers
The widely accepted definition is a wave roughly three times the average height of its neighbors.
No one is certain yet just how frequently freak waves form; accurate numbers are extremely difficult to collect given the waves' rare and transient nature. With more sophisticated monitoring and modeling—and as first-hand accounts are taken more seriously—the waves' prevalence appears to be rising. "[Rogue waves] are all short-lived, and because ships are not everywhere, the probability that a ship encounters one is relatively small," says
Daniel Solli, who studies the optical version of rogue waves at the University of California, Los Angeles. "But with increasing amounts of oceanic traffic in the future, the likelihood of encountering them is getting larger."
Forming fearsome waves
Various theories exist for how rogue waves form. The simplest suggests that small waves coalesce into much larger ones in an accumulative fashion—a faster one-meter wave catches up with a slower two-meter wave adding up to a three-meter wave. One burgeoning wave can actually soak up the energy of surrounding waves.
