The Strait of Gibraltar (2)#
The older packet (labeled) contains at least 14 waves, which can be counted like tree rings. A younger group is forming near the middle of the strait (marked by the carat south of Gibraltar).
The waves are generated as a diurnal tidal pulse flows over the shallow Camarinal Sill at Gibraltar. The waves flow eastward and refract around coastal features; they can be traced for as much as 150 km.