So Much To Learn About The Oceans From Sand

As reported by Cornelia Dean for The New York Times.

If you’re looking to check out the sand at Pipe this might be one way, though a dangerous option. Photo: Bielmann/SPL

CORVALLIS, Ore. — As a young geophysicist in the 1980s, Rob Holman attended a conference in San Francisco that included a field trip to a beach. Dr. Holman, who grew up inland, in Ottawa, stared at the ocean, assessing the strengths and vectors of the waves and currents. But when he looked around, everyone else was studying the sand.

He realized, he recalled, that “sand is not the same everywhere.” So he started collecting it. “I collected a few samples and put them in jars,” he said. “Then I had so many I built a rack. Then I built three more racks. Then I built four more.”

Today Dr. Holman is best known as a coastal oceanographer at Oregon State University whose computerized photography system, called Argus, has given researchers new ways to observe and measure beaches. But he still collects sand, which he displays on shelves in the corridor outside his office. By now he has almost a thousand samples. They come from his travels and from geologists and amateurs all over the world (including this reporter) who send him grainy shipments in envelopes, plastic bags, paper towels and other wrappings. Each offering is dried and transferred to glass laboratory jars a few inches high, which Dr. Holman labels by latitude and longitude of their site, as best he can determine them from the sometimes sketchy information his contributors provide.

The collection includes sand from all continents, including Antarctica. “Dutch colleagues are particularly good” at mailing in sand, Dr. Holman said. “Africa is lacking in samples,” a deficiency he attributes in part to an unfortunate accident. “Early on, I had a rack collapse,” he said.

Though these offerings have not necessarily ended up in the formal display, he has also received a bottle containing a gimmick portrait in purple sand, Hawaiian sand samples sold in packages to tourists, salt and pepper (“that was actually my secretary”) and all kinds of other things that were found on beaches, or might have been, including jelly beans and M&Ms. He accepts contributions of sand from inland riverbeds and places like Ayers Rock, in the Australian Outback, and even from hotel lobby ashtrays “if it’s a high-class place,” he said. These are listed as “miscellaneous.”

Occasionally offerings come from the community of psammophiles (formally, plants that live in sand) — people who collect sand for fun. There are more of them than one might think. Sand collecting “is not a new hobby or a passing fad,” according to the Web site of one group, the International Sand Collectors Society (www.sandcollectors.org). Its motto: “Discovering the World, Grain by Grain.”

Dr. Holman watches some sand sites, but from a distance. “I don’t participate in the chats,” he said.

For Dr. Holman, what started almost as a joke has become a valuable teaching tool. Geology students at the university study his collection, and they can learn a lot from it. “This row is a north to south transect along the East Coast,” he said one day recently, pointing to tubes containing samples collected at sites from Cape Cod to Key West. “It just gets lighter and finer.” That is because most of the time sand is not stationary on the beach. On the East Coast, “the big waves come in from the northeast, and they drive the littoral drift predominantly from north to south,” Dr. Holman said, referring to the longshore movement of sand.

By the time a grain of sand washes up on a beach in Florida, it has been battered by waves for a long time. “The physical action of being continually beaten causes the grains to break down, the angular corners to break off,” he said. “They become more rounded.”

And relatively dense mineral grains, like garnet, have settled out. The result is a row of samples shifting from the relatively dark, coarse grains of the Northeast to the fine white beach sand of the Southeast.

The rack “illustrates a lot of the things we need to know about how beach sands are different,” he said. “I have occasionally taken in sand to a student exam and said, ‘Tell me about this beach.’ A good person can do very well. There are a number of characteristics you can look at — the nature of the sand and the shape, where would the minerals come from, different transport and aging. Those all affect the sand you see on the beach.”

Dr. Holman also takes the teaching rack with him when he gives talks to the public, an effort to encourage people “to think about what they see on beaches.”

For the full article, head to The New York Times.

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