Playing with sand on an industrial scale at Weymouth Beach in Dorset this week, earth moving machinery has been restoring the shore to pristine condition by redistributing imported sand – ensuring plenty for sun-bathing and sand castle-making before the better weather and the influx of visitors arrive in this new season.
Some more images showing the subtle colour transitions and delicate branching patterns that characterise the low relief natural sculptures in the fine clean sand on the shore near Picquerel Point at Grand Havre in the Channel Island of Guernsey. The dendritic patterns have been created by sea water draining down the beach as the tide recedes; and this has led to a sorting out of particles by size, weight, and colour. The darker sediments that outline and emphasise the design may be organic remnants or different darker minerals. These patterns are the best of their type that I have seen – perhaps due to the very fine sand. The patterns are so delicate they could almost be drawings.
Click on any image to view in larger format in a gallery.
Subtle colour transitions and delicate branching patterns characterise the low relief natural sculptures in the fine clean sand shown in this photograph. It was one of many taken on the shore near Picquerel Point at Grand Havre in the Channel island of Guernsey. The dendritic patterns have been created by sea water draining down the beach as the tide recedes; and this has led to a sorting out of particles by size, weight, and colour. The darker sediments that outline and emphasise the design may be organic remnants or different darker minerals. These patterns are the best of their type that I have seen – perhaps due to the very fine sand. They look like pencil sketches. I am definitely going to frame some of the images.
The sand on the Island of Herm, which is one of the Channel Islands, is mostly made of shells and shell fragments. A good place to examine the sand is Belvoir Bay where waves and currents wash shells ashore and break them up. The small cove lies at the foot of modest cliffs of Herm Granodiorite with xenoliths; and eroding rocky outcrops strew the shore at the base of the cliffs. Hollows and crevices in these rocks are filled with coarse shell sand containing many intact little shells of both bivalve and gastropod molluscs. Even minute sea urchin tests survive. I took a handful of the sand home to photograph against a scale, and compare them with some mature-size shells from the same beach and nearby Shell Beach. I have fond memories of visiting the island and collecting shells there forty years ago.
The shape of natural abstract sand sculptures, like these ripples on the seashore, result from complex interactions of water and substrate which are the subject of much research in the field of fluid mechanics. They are described as “small-scale three-dimensional bedforms due to interactions of an erodible bed with a sea wave that obliquely approaches the coast, being partially reflected at the beach” (Roos & Blondeaux 2001). Different combinations of three main perturbation agencies create different ripple designs.
Roos, P.C. and Blondeaux, P. (2001) Sand ripples under sea waves. Part 4. Tile ripple formation, J. Fluid Mech. vol. 447, pp. 227-246.
Follow in my footsteps with a virtual walk along beautiful Rocquaine Bay on the west coast of the Channel Island of Guernsey. It is protected by a long sea defence wall which has employed different construction techniques along its length; mostly using local stone but also with along stretch of reinforced concrete (probably originating from German occupation World War II fortifications). The beach is both rocky and sandy with some pebble patches. Seaweeds of every colour abound. Huge limpets with white shells cluster on the bright orange-spattered L’Eree granite bedrock while outcrops of monochrome microgranodiorite occur on the upper shore near Fort Grey. Marine worm casts cover the softer muddy sands. Streams flow across the shore, their clear shallow water reflecting sunlight from the ripple crests and creating shadow patterns. A small stone jetty looks marooned among the rocks and a multi-coloured carpet of weed. Small boats bobbing in the turquoise water, rusty buoys and chains half-buried in seaweed, and algae-encrusted mooring ropes add to the evidence for fishing and leisure boating activities.
Click on the first picture to view the images in the gallery in the sequence that they were taken during the walk.