Coastal lakes hold hurricane history.Catastrophic hurricanes elude e·lude tr.v. e·lud·ed, e·lud·ing, e·ludes 1. To evade or escape from, as by daring, cleverness, or skill: The suspect continues to elude the police. 2. long-term forecasting, in part because their historic documentation dates back only 120 years - a span too short to reveal how often such storms tend to recur. Now. two scientists have found a way to extend that record backthousandsof years. Bytracingthe fingerprints that ancient hurricanes left in lake sediments near the Alabama coast, they have taken the first step toward calculating the risk of a devastating dev·as·tate tr.v. dev·as·tat·ed, dev·as·tat·ing, dev·as·tates 1. To lay waste; destroy. 2. To overwhelm; confound; stun: was devastated by the rude remark. storm in that region. We have reconstructed hurricane activities in that part of the Gulf [of Mexico] during the last 5,000 years," says geographer Kam-biu Liu of Louisiana CODE, OF LOUISIANA. In 1822, Peter Derbigny, Edward Livingston, and Moreau Lislet, were selected by the legislature to revise and amend the civil code, and to add to it such laws still in force as were not included therein. State University in Baton Rouge Baton Rouge (băt`ən r  zh) [Fr.,=red stick], city (1990 pop. 219,531), state capital and seat of East Baton Rouge parish, SE La. .
Using radiocarbon dating radiocarbon dating n. The determination of the approximate age of an ancient object, such as an archaeological specimen, by measuring the amount of carbon 14 it contains. Also called carbon dating, carbon-14 dating. to determine the age of hurricane sand deposits, Liu and graduate student Miriam L. Fearn found that extremely violent hurricanes have raced through the area about every 600 years. Given that the last such storm hit this region 770 years ago, "the Alabama coast is likely to be struck by a major hurricane within the next century," Liu says. He and Fearn describe their study in the September GEOLOGY. Focusing on coastal Lake Shelby allowed them to date the ancient hurricanes to within 200 years, says Liu. Previously geologists looked at much older, mostly marine sediments that are often too perturbed per·turb tr.v. per·turbed, per·turb·ing, per·turbs 1. To disturb greatly; make uneasy or anxious. 2. To throw into great confusion. 3. for exact dating," he explains. Coastal lakes are better preserved and hold organic material that can be accurately dated, he says. The researchers started out by locating the sand that Hurricage Frederick - a strong storm that struck in 1979 - had hurled away from beaches and into the lake. Guided by the appearance of the sand layer left by Frederick, they scanned lake sediment cores for older hurricane-sand strata. Then they radiocarbon-dated the older hurricanes, measuring the proportion of carbon-14 in the sediment layers around the sand. These deposits must have stemmed from catastrophic hurricanes, Liu reasoned, because the winds managed to fling them into the middle of the lake-an area so far from the beaches that Frederick's sand deposits hadn't reached it. Liu is now extending this pilot project to a dozen sites along the Gulf of Mexico Noun 1. Gulf of Mexico - an arm of the Atlantic to the south of the United States and to the east of Mexico Golfo de Mexico Atlantic, Atlantic Ocean - the 2nd largest ocean; separates North and South America on the west from Europe and Africa on the east , hoping to assemble an overall pattern of prehistoric hurricanes within the next two years. |
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