Sea can cause individual (unexpected) rogue waves much higher than normal. Most waves are less than high and it is not unusual for strong storms to double or triple that height; offshore construction such as wind farms and oil platforms use metocean statistics from measurements in computing the wave forces (due to for instance the hundred-year wave) they are designed against. Rogue waves, however, have been documented at heights above . The top of a wave is known as the crest, the lowest point between waves is the trough and the distance between the crests is the wavelength. The wave is
Coda Wave Interferometry The unperturbed travel time is given by formula_8 where formula_9 is the coda wave velocity. The perturbed travel time is formula_10 where formula_11 is the velocity perturbation. Thus formula_12 . If the relative velocity perturbation is assumed constant, then formula_13 where t is the center time of the employed time window. Thus, the travel time perturbation depends on the arrival time of the coda wave, but not of the particular path followed. Coda Wave Interferometry Coda Wave Interferometry is an ultrasound technique for detection of weak and local changes in complex inhomogeneous media. Sound waves that travel through a medium