Word: silting
(lookup in dictionary)
(lookup stats)
Dates: during 1980-1989
Sort By: most recent first
(reverse)
...water recedes, the river bottom emerges, providing clues to a lost past. On an ugly beach of sand and clay in Arkansas, just downstream from Memphis, archaeologists have struck what they consider gold: large chunks of riverboats built in the late 1800s and long buried in silt...
Trying to reproduce a cherished past is difficult when so much has changed. Larry's childhood swimming hole long ago was filled with silt from the mines. The movie house is gone too, displaced by cable television and the VCR. The Nelsons have both. Out of fear for their safety, the Nelsons do not allow their kids to explore the woods by themselves, as Larry did, or even walk or ride their bikes too far from home alone. "There was a lot more they was allowed to do back then, like go out in the woods and not be afraid...
While the oceans are rising, some coastal land is actually sinking. Much of the East Coast, for example, is made up of silt sediments deposited from rivers, bays and inlets over the past 5,000 to 8,000 years. As the sediments gradually compress under their own weight, the surface sinks lower. On the Gulf Coast, a process called subsidence, caused in part by the extraction of groundwater and petroleum from subterranean layers of sand and clay, has forced the land, already virtually at sea level, to drop 3 ft. a century. In all, the coastline of the northeastern...
Jetties can cause beach larceny on an even grander scale. Long concrete or rock structures, they jut out into the water to keep inlets and harbors navigable by keeping sand and silt from drifting in. Like groin fields, jetties can keep sand from replenishing beaches down current. The construction 90 years ago of a pair of jetties to improve the harbor at Charleston, S.C., altered currents and natural sand drift so drastically that there is no beach left at high tide at nearby Folly Beach. In Florida an estimated 80% to 85% of the beach erosion on the state...
Once the trees are gone, denuded slopes are eroded by rainfall, which has been washing soil into 20-sq.-mi. Madden Lake at the rate of half a million tons a year. A study by Hydrologist Luis Alvarado of the Panama Canal Commission shows that silt accumulating at the bottom of the lake has reduced its storage capacity by 5%. By the year 2000 the loss could be as high as 10%, and by 2020 nearly...