Storytime 45

Jekyll Island dead tree with tidal wake
It would be easy to miss a little detail in today’s image, and in fact I likely missed it when I was shooting the frame, three years ago, but there’s evidence of a curious effect to be found here. It’s subtle, and may be missed if your monitor’s gamma is set incorrectly, because we need the details in the shadows.

In my defense, I did see at least a portion of what I’m referring to, since I specifically shot a few examples while out there waiting on sunrise, but I’m not sure I saw everything here. This is Jekyll Island off of the coast of Georgia, source of quite a few images on the blog now, and more specifically the northern tip of the island, often called Driftwood Beach even though the wood thereon doesn’t drift (or at least didn’t at the time – with a couple of hurricanes since this was taken, I suspect this particular stump isn’t even there anymore.) What I’m referring to isn’t the little blip of the St Simon’s Island lighthouse there in the fork (which was intentional,) but the properties of the sand at the base. It was clear that I was the only person to have walked out there since high tide had been through, sometime in the wee hours of the morning, and the sand was displaying the behavior of the advancing water. The stump itself caused a turbulent little eddy that dug out more sand directly from its base, but it was the manner of the waves that it broke that made the ripples in the wake of the stump – in two different directions. That’s the part that I can’t immediately explain. Which is not that say that I won’t make the attempt; we now enter Talking Out of My Ass mode.

The stump itself seems to sit at the head of a slight rise, possibly self-caused through its effect on the wind coming off of the water, and this rise broke the smooth flow of incoming water, perhaps during a previous high tide – tides have different strengths throughout the day, and thus different names, and I’m reading (illiterately, most likely) a weaker flow that created the ripples to the center-right, running down the back side of the slope as the water just barely broke over top – so, down towards the lower right of the image (the ripples/ridges themselves would be perpendicular to the flow of the water.) But then came a later, stronger and higher tide, whirling around the base of the stump, and leaving a set of sand ripples more in line with the actual direction of the waves as they rolled up the beach, those to the left flowing towards the lower left corner of the image. Portions of the earlier tidal flow were scoured clear on the right side of the frame, but the rise was high enough to prevent their complete eradication.

That’s my guess, anyway – I wasn’t there when this happened, and don’t know enough about waves to be sure, and didn’t crouch down to make careful comparisons of the height of the sand in different areas, so the value of this speculation is infinitesimal. But something happened there to make two different sets of sand ripples – it could always have been aliens, I suppose…

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