Full Sand Moon

Wed, 08/10/2011 - 12:14pm

It is the season of sandcastles and hot-footing it across black sand. The dog days of summer when bodies can find their own form in warm soothing sand. We may take it for granted but the sandy shores of Block Island form a complex and dynamic buffer between stable land and the animated sea.

In a single day the gentle slope of a sun-baked beach can be transformed by easterly ocean swells to a beach with a 24-inch bench dividing the shoreline lengthwise; hard, wet, seaweed-strewn beach to the seaward, and long shallow pools of water perched on the upper — landward — ledge of sand.

The erosive effects of wave action, downhill running water and wind are powerful forces for the sculpting of the island’s shoreline, but the sculpting tool is not the single determining factor of the form. Small-particle sands yield clay-ey hoodoos from the bluffs, evoking images of badland mesas and petrified druids. Larger sand grains are blown and rounded by the wind into dunes that are reshaped by every footfall and slowly march landward.

Depending on the mineral that was the source of those grains, the quartzy dunes may have a skirt of overlaying, heavy-iron black sands that become extremely hot as they absorb the sun’s radiated heat. Or the transition zone between the molded dune and the flatter beach may have a reddish tint — a confectioner’s dusting of tiny garnets.

Finally, large-sized sand grains — sharp-edged, angular, not yet worn smooth — flow like molten metal-smith’s iron into alluvial fans wherever water and gravity conspire. These wedges of sand, found at the interface of land and beach, can be tiny — the size of your hand — or they can be giant, resting at 45-degree angles on nearly the entire face of a 150 foot tall bluff.

Sand is a marvelous material. As is also true for snow, sand comes in a huge variety of shapes, sizes and textures. Sand is a critical part of the island’s substrate; it can be irritating when it is swirling around your house or it can offer warm comfort to body and soul. Think of the island’s sandy shoreline as a canvas or armature for nature’s designs and human imagination. Wet sand, dry sand, black sand, red sand, course sand, fine sand … ahhh, the stuff of islands and sandcastles.

In keeping with this series of “Animal, Vegetable, Mineral” articles, I propose adding a Block Island full moon name: sand moon. Full moons bring dramatic tides, so this month’s full moon on Aug. 13 provided plenty of beach exposure for considering the full range of sands at our fingertips. This year the full moon coincided with the peak of the Perseid meteor showers, thus obscuring the full effect of an evening’s shooting stars. Even so, this week had provided great opportunities for seeing those magic glints in the sky. Perhaps this moon would be more aptly named the Perseid full moon.

The following August events and Ocean View Foundations programs are sure to provide opportunities for sampling the sands of August.

Aug. 25 – Environmental Film Night at the OVF Pavilion: solar powered films under the stars.

Aug. 24 – Mystery Walk, call 595-7055 to sign up.

Aug. 25 – B.I. 350 Committee Heritage Presentation Series: Varekamp and Thomas present a program on the environmental history of Block Island.

Aug. 31: Twilight Walk and Night Sky Viewing, Hodge Preserve.

(Go to oceanviewfoundation.org or BI Times ad for schedule details)