Taxonomy term

september 2015

Subducted seawater the source of fluid-rich diamonds

Subducting oceanic plates that dive hundreds of kilometers beneath Earth’s surface carry with them cargoes of sediment and seawater. As the plate heats up the deeper it sinks, this seawater not only initiates melting in the rock above it, but can also trigger diamond formation, suggest the authors of a new study in Nature.

30 Sep 2015

Declining U.S. water use a challenge for models

Americans are using less water today than they have at any time since 1970, according to a report by the U.S. Geological Survey (USGS), which has tracked water use since 1950 and issues reports every five years. 
 
27 Sep 2015

Mineral Resource of the Month: Iodine

Iodine is a bluish-black lustrous solid (violet-colored in its gaseous state) found primarily in seaweed, underground brines associated with petroleum deposits and caliche ore deposits. 

26 Sep 2015

Energy Notes: March 2014-2015

Oil and petroleum imports data are preliminary numbers taken from the American Petroleum Institute’s Monthly Statistical Report. For more information visit www.api.org.

26 Sep 2015

Benchmarks: September 26, 1991: Crew sealed inside Biosphere 2

It takes about an hour to drive from Tucson, Ariz., to the Biosphere 2 research facility, perched atop a plateau in the Santa Catalina Mountains. Through its glittering glass walls, you can still see the shadowy silhouette of the Brazilian rainforest that grows inside. Indeed, the facility once enclosed numerous small-scale experimental ecosystems — from a swath of swaying savanna to a 700,000-gallon ocean complete with its own coral reef. And, beginning on Sept. 26, 1991, Biosphere 2 enclosed a crew of four men and four women who would call the bubble home for two years.
 
26 Sep 2015

Aerosols help mitigate ill effects of Amazon fires

Forest fires across the Amazon Basin — many of which are set intentionally to clear land for human use — burn thousands of square kilometers each year, releasing roughly 240 billion kilograms of stored carbon to the atmosphere. According to a new study, however, the vast amounts of black carbon and other aerosolized particles also sent into the skies by such fires offset much of this carbon loss by stimulating increased photosynthesis.

24 Sep 2015

Dinosaurs used the same nests repeatedly

Fossil dinosaur eggs and nests offer clues about dinosaur development and behavior: Based on past work, for example, scientists have thought that some dinosaurs, like oviraptors, brooded, or sat on their eggs, much like modern birds do. Now, the results of a new study describing two fossil egg nests suggest that some dinosaurs used the same nesting sites again and again.
23 Sep 2015

Injection experiment offers new view of fluid-filled faults

Scientists have known since the late 1960s that injecting fluids underground can cause earthquakes if those fluids find their way into slip-prone fault zones. Evidence of fluid-induced quakes has continued mounting in recent years with observations of abnormally high levels of seismicity in the central U.S., coincident with increased injections of wastewater into the ground — mostly related to oil- and gas-mining operations. But understanding the inner workings of fluid-filled faults is challenging because researchers have been limited by how close they can get to study them. Now, a new study is offering a glimpse into the future of induced-seismicity studies by monitoring fault motions on the spot and in real time.
 
19 Sep 2015

Travels in Geology: Rafting the Pacific Northwest's heavenly Hells Canyon

Few roads and only steep, difficult trails run down into Hells Canyon — the deepest canyon in North America — which forms part of the border between Oregon and Idaho. But the location is popular among boaters, whitewater rafters and fishermen, and a trip down the river reveals some spectacular rocks.

18 Sep 2015

Damming the salmon

In the 1940s, the state of Idaho decided that the Salmon River would be left to flow freely while the Snake would be developed for hydroelectric power to become Idaho’s workhorse river. To date, a total of 15 dams have been built along the Snake for a variety of purposes, from irrigation to flood control to hydroelectricity. Hells Canyon is home to three hydroelectric impoundments: the Brownlee, Oxbow and Hells Canyon dams, built in 1959, 1961 and 1967, respectively. Together they have a maximum capacity of 391 megawatts of power production. 
 
18 Sep 2015

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