Homage to the Sandman

Bob Osborne, the “Oz-man,” as some of his students called him, was the sort of person you were glad to find peering at you across a dinner table because he loved so many things and spoke so well about them. But of all his passions, it was the sand of Southern California’s beaches that he loved best.

As would befit a sedimentologist and chairman of USC’s department of geology, Oz knew everything there was to know about sand. He and his students shoveled millions of grains of it into Ziploc bags; went out in boats, in scuba gear; took samples from rivers where they enter the sea. They collected coarse-grained samples, fine-grained samples; sandstones, silt stones, clay and mud.

They collected so much sand that there are now two subterranean labs at USC (as well as the space under the tennis courts’ bleachers) filled with the stuff. Sand from all of our beaches, from Ventura to the Mexican border, sits there silently on tables and chairs, on the floor and on desks. Thousands of bags from Santa Monica and Rincon, from Hermosa and Manhattan and Huntington and Oceanside and Carlsbad.

What Oz found was how some of our beaches, such as Santa Monica, are now starved for sand because our dammed and channeled rivers no longer bring it to the sea. More than 160,000 cubic yards of beaches along Santa Monica Bay are carried southward by littoral drift every year, leaving it permanently hungry for the sand periodically trucked in to keep it wide.

Paradoxically, Oz also found that in the biggest storms, new sand is washed up to the beach from the continental shelf, replacing some of what is lost. Which is good and bad: beach erosion is slowed, but some centuries from now, when the sand of the continental shelf is greatly depleted, some of our beaches may disappear completely.

Oz died unexpectedly in 1994, at age 55, after an eye operation, and his work is being completed this year by Rahul Bahadur, a doctoral student. “The United States Geological Survey has been here to look at the sand,” Bahadur says. “It was a joy to collect. Don’t worry--once I’m done with it, no one is going to throw this stuff away. It’s quite valuable.”