As the beach changes continuously we measure everyday with a RTK-GPS system. But, what actually happens with the beach when it is covered with water and waves? To understand better how the beach changes during high tide, we measure the bedlevel change every 15 minutes. We do this for 4 high tides, each one characterized by other wave conditions. Here we will show the beach profile changes during the high tide of a very calm day, with wave heights < 0.5 m.
In the initial profile (in black) an intertidal sand bar is visible. During this particularly calm high tide, when the sand bar is covered only for a few centimeters with water, the sand bar grows a little in height (~ 5 cm) and moves a little shoreward (~ 2 m) (see final profile in red). The bar grows mainly in height during the first hour (8:00-9:00) of the upcoming tide. The snapshot video below gives some insight in how gently the bar is moving towards the shore.