National Geographic : 1990 Aug
GEOGRAPHICA~AION G iA AI MAG AINE AUUlA1l0 RANDYBRANDON,ALYESKAPIPELINE SERVICECO. Pipeline Is Corroded, Alaska Oil Still Flows Corrosion has damaged under ground sections of the trans Alaska pipeline (GEOGRAPHIC, November 1976) and will require extensive repairs over the next three to five years. But the daily flow of 1.8 million barrels of North Slope Oil from Prudhoe Bay to Valdez-one-quarter of domestic production-will not be seriously interrupted, industry and government experts say. The rust is believed to stem from the failure of a layer of epoxy to bond properly with the steel pipe or the moisture-proof tape wrapped around it. The damage was detected and then measured by ultrasonic testing equip ment (above). More than 800 anom alies-areas where the half-inch thick ness of the pipe had been reduced by at least 10 percent-were found. In 1989 workers dug up 305 sections; 32 needed repair, in the form of sand blasting the pipe, welding on a rein forcing steel sleeve, applying a new and improved epoxy coating, and rewrap ping with waterproof tape. The most significant damage was dis covered in an 8.5 -mile section of under ground pipe in the Atigun River region of the Brooks Range, about 160 miles south of Prudhoe Bay. The section will be completely replaced in 1991. The pipeline must be shut down for about two days while new concrete-coated pipe is spliced into the main line. All the corrosion has occurred on the pipe's exterior, and only on under ground portions. About half of the 800 mile pipeline is carried on stilts above ground. The eight-billion-dollar line began operating in 1977. Repair costs are estimated at between 600 million and more than a billion dollars. A Monarch Butterfly Population Explosion n mid-August every year, monarch butterflies in eastern North Amer ica begin to pack up and head south for the winter. Eventually they arrive in Mexico in such numbers that they turn the trees and hillsides orange. But the monarchs that begin making the trip this month will have quite a chal lenge if they are to top last year's migra tion. It was one of the biggest. Fred Urquhart, a Canadian scientist who has been studying monarchs since 1937 and who described the discovery of their winter haven in the August 1976 NATIONAL GEOGRAPHIC, says that the population boom was caused by 1989's unusually warm early summer weather. Caterpillars turn into butter flies quicker in warm weather, and the result was an extra generation of monarchs, explains Urquhart, whose research was supported for many years by the National Geographic Society. It is impossible to estimate numbers since there are so many. But Urquhart says that when the butterflies arrived last year at the 12 Mexican sites now known to be their winter home grounds, they roosted on more trees than usual, and there were more monarchs per tree. It's a "Lousy" Job, but Science Has to Do It Death and taxes aren't the only inevitabilities. So are head lice. Joseph Zias, an Israeli anthro pologist, saw a photograph (GEO GRAPHIC, February 1985) of a head louse found in the intestines of a Greenland Eskimo mummified 500 years ago. He and Kosta Y. Mum cuoglu, a medical entomologist, began examining human hair from archaeo logical sites in Israel for signs of lice. Early results were negative, but when they looked at combs found there, the picture changed. "Right off the bat, the combs turned up positive," says Zias. The pair have now found the remains of lice or their eggs from a dozen sites, ranging in age from 9,000 years ago to about A.D. 800. They hope to recover MICHABAR-AM human blood from inside one of the lice. "With it," says Zias, "molecular biologists may be able to replicate the genetic material of someone bitten by a louse." The scientists are impressed by the combs-mostly made of boxwood but some of ivory or bone-used thou sands of years ago to get rid of lice. "They probably were more effective than many modern combs," Mum cuoglu says. One comb (bottom) held the remains of four lice and 88 eggs. In an Empty Region, a Series of Surprises The Kimberley region is a vast, empty area in the northeast corner of Western Australia. Only 23,400 people live within its 420,000 square kilometers. A 2,000-kilometer-long stretch of coast between two of the region's principal towns is almost entirely unpopulated. CLAYBRYCE Small wonder, then, that scientists have known little about the inverte brate inhabitants of the region until recently. When Fred E. Wells of the Western Australian Museum led a sci entific team into the Kimberley to find out what kinds of snails, crabs, and worms live on and around more than 80 islands off the coast, he expected some surprises. But they weren't all of the sort he envisioned. The team, supported in part by the Society, found four new genera and 48 new species of land snails, plus at least six new species of marine worms. In addition, they uncovered evidence that creatures known to live elsewhere, such as an octopus (above), also inhab it the Kimberley. But, unexpectedly, the group also unearthed two Aboriginal burial sites. One contained a bark package of human bones coated in red ocher and rubbed with kangaroo fat. Finally, the scientists found that many of the islands have never been officially named. They have some sug gestions and hope that about 40 islands will now bear names for the first time.