Forgive Me, For I Have Sand

Courtesy of the New York Times, I've been reintroduced to my long-lost fondness for sand. Apart from those occasions when it would find its way into my swimsuit, I'd forgotten how much I appreciate the stuff. As such, I enjoyed learning of Oregon State University's Rob Holman, who has amassed a collection of hundreds of samples of beach sand from shorelines around the globe, and whose studies of global coastal environments reveal the dynamic nature of where sea and land shake hands.

With all due apologies to Julie Andrews and her opening number to The Sound of Music, the hills are just fine and all, but it's actually the beaches that are alive. A couple decades separate me today from my time as a student of the earth sciences. To this day, when it comes up in conversation that in college I studied geology, more often than not I'll get a question about rocks. And more often than not, I'll shrug. Honestly, I know just about nothing about rocks.

And another earth science confession: The thing that actually drew me into the field was that — because a student of geology is forced to think in terms of hundreds of millions of years — I enjoyed what the subject did to alter my sense of time (which by itself suggests I may have done well to have chosen philosophy instead). But one of the sub-disciplines that truly gripped my attention was geomorphology, which concerns itself with how landforms come to be and change over time. And especially interesting was the inquiry into landforms, and the processes that sculpt them, that arise from moving water: from flowing rivers, and from the wave energy of the oceans.

What we see as a beach today has come to be based not only on the type of local rock along the shoreline for wave energy to give its unending beatdown (pummeling it into sand over time), but also on the type of rocks whose products of erosion have been delivered by rivers (and, in places, by glaciers) to the shoreline, much of that from very long distances. No two beaches are alike, in no small measure because their sand itself varies so widely.

You think sand is just sand? Go have a look. We like to think of land as solid and permanent, but you don't even have to study beaches know otherwise. Go have a game of volleyball or a nice jog on some dry beach sand, and you'll know: Sand yields to force. The illusion of our annual returns to the same favorite beach summer after summer is belied by sand's constant dance. It's swept alongshore by the ton in real time as waves approach the shore at oblique angles. Beach sand moves offshore in the winter, and then it returns in the summer, with the predictable changes in seasonal wave patterns.

The beach you see is an always-changing system that is a mere few thousand years old, which in terms of geologic time, is the blink of an eye. Blink again and you'll miss it. Heavy population concentration along our coasts results in a lot of human activity in these dynamic and sometimes fragile environments. The chance to experience and interact with the ocean environment is an invaluable and enriching touchstone for so many of us, but a light touch is crucial. I'm not knocking beach houses, but they're not for me. It's the sediment that counts.