Here are eight photos of the reflections of masts of yachts on a day of high atmospheric pressure in a harbour on the east coast of Ireland. All taken during a pier walk in Dún Laoghaire with a polarised telephoto lens.
They look like the graphs of time series events that geophysicists call ‘traces’. The trace being the mark a pen makes on paper to record earthquakes, for example. A series of amplitudes that occur as sound impinges on layers of rocks below the surface. Rock layers that have differing impedances. Or the ‘wireline’ logs that are made from borehole measurements, returned to the surface by wire to a recording device.