The Yarlung-Tsangpo River in southern Asia drops rapidly through the Himalaya Mountains on its way to the Bay of Bengal, losing about 7,000 feet of elevation through the precipitously steep Tsangpo Gorge.
For the first time, scientists have direct geochemical evidence that the 150-mile long gorge, possibly the world’s deepest, was the conduit by which megafloods from glacial lakes, perhaps half the volume of Lake Erie, drained suddenly and catastrophically through the Himalayas when their ice dams failed at times during the last 2 million years. (more…)
Have you ever dropped a stick into a river and wondered where it might go if it floated all the way downstream? Now you can trace its journey using Streamer – a new on-line service from the National Atlas of the United States®.
Streamer is an online map service that lets anyone trace downstream along America’s major rivers and streams simply by picking a point on a stream. Streamer will map the route the stream follows. (more…)
The increasing production and use of antibiotics, about half of which is used in animal production, is mirrored by the growing number of antibiotic resistance genes, or ARGs, effectively reducing antibiotics’ ability to fend off diseases – in animals and humans.
A study in the current issue of the Proceedings of the National Academy of Sciences shows that China – the world’s largest producer and consumer of antibiotics – and many other countries don’t monitor the powerful medicine’s usage or impact on the environment. (more…)
Some of the steepest mountain slopes in the world got that way because of the interplay between terrain uplift associated with plate tectonics and powerful streams cutting into hillsides, leading to erosion in the form of large landslides, new research shows.
The work, presented online May 27 in Nature Geoscience, shows that once the angle of a slope exceeds 30 degrees – whether from uplift, a rushing stream carving away the bottom of the slope or a combination of the two – landslide erosion increases significantly until the hillside stabilizes.
“I think the formation of these landscapes could apply to any steep mountain terrain in the world,” said lead author Isaac Larsen, a University of Washington doctoral student in Earth and space sciences. (more…)
About the image: A now dry Colorado River delta branches into the Baja/Sonoran Desert near the Sea of Cortez. Image credit: Pete McBride
Rivers and streams supply the lifeblood to ecosystems across the globe, providing water for drinking and irrigation for humans as well as a wide array of life forms from single-celled organisms up to the fish humans eat.
But humans and nature itself are making it tough on rivers to continue in their central role to support fish species, according to new research by a team of scientists including John Sabo, a biologist at Arizona State University.
Globally, rivers and streams are being drained due to human use and climate change. These and other human impacts alter the natural variability of river flows.
Some affected rivers have dried and no longer run, while others have seen increases in the variability of flows due to storm floods. (more…)
