Word: sediment
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Dates: during 2000-2009
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...nearly 30 years ago that physicist Luis Alvarez and his son Walter, a geologist, proposed the giant-impact theory of dinosaur extinction. Their evidence was compelling: a thin layer of iridium in the earth's sediment dating to about the time of the die-off. Iridium is rare on Earth but common in asteroids. The iridium layer, mapped by the Alvarezes in scattered sites around the world, suggested an asteroid that vaporized on impact, spreading a cloud throughout the stratosphere. The argument seemed sealed in the 1990s, when geologists realized that a huge crater centered near Chicxulub, Mexico, was almost...
...Opponents of the scheme said Able UK's plan to dredge a nearby estuary for a series of wind turbines - an addendum to the original ship-breaking application - would unearth sediment containing dangerous heavy metals such as cadmium and mercury, and toxic chemicals like dioxin. They also question Able UK's plans to bury asbestos and other toxins from the ships at the nearby Seaton Meadows landfill...
...Looking at the Chongqing by the intersection of the Jialing and Yangtze rivers, it wasn’t hard to see why. The water was murky grey and appeared to contain everything from household garbage to industrial sediment and waste. And it’s really no surprise, since environmental regulations do little to prevent the dumping of waste into water bodies by factories and farms, including everything from petroleum to ammonia nitrogen to mercury. Since China has only one-fifth the water supply per capita as the U.S., conservation and stricter regulation is essential in order to preserve...
...city in a bowl." Levees and loss of wetlands did not cause it to sink - they simply sped up the process. The city sinks by compacting the mud on which it is built. And even if the Mississippi River ran its course unchanged, New Orleans would be buried by sediment. It would sink faster under the weight. We should not rebuild New Orleans in the same location. No city can exist there for long. We are committing future generations to a similar fate. Todd Johnston, State College...
...while 90% of the basin's residents are subsistence farmers who largely depend on the Mekong's nutrient-rich waters to feed their fields. Yet Chinese dams, along with engineering projects to make the river navigable by larger vessels, have begun to ravage the river's ecology by blocking sediment and producing unnatural water flows that dissuade fish migration and spawning. The nonprofit Southeast Asian Rivers Network estimates that fish stocks on the Thai-Laos border have already declined by half because of Chinese activity. Farmers, too, complain that the once-predictable floods needed to nourish their paddies have been...