Tag Archives: river

River Buries Permafrost Carbon at Sea

New study traces the fate of carbon stored in thawing Arctic soils

As temperatures rise, some of the organic carbon stored in Arctic permafrost meets an unexpected fate—burial at sea. As many as 2.2 million metric tons of organic carbon per year are swept along by a single river system into Arctic Ocean sediment, according to a new study an international team of researchers published in Nature. This process locks away carbon dioxide (CO2) – a greenhouse gas – and helps stabilize the earth’s CO2 levels over time, and it may help scientists better predict how the natural carbon cycle will interplay with the surge of CO2 emissions due to human activities. (more…)

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Unraveling the Napo’s mystery

In the United States, rivers and their floodplains are well-documented and monitored. Ecuador’s largest river, however, remains largely mysterious.

Research led by Michigan State University is helping the South American country unravel the Napo River’s mystique to better balance its economic and environmental treasures. (more…)

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Microbes in the Mississippi

Professor and students study how microbial life changes along the river

The mercury is pushing 100, but professor Michael Sadowsky and two assistants leave the indoor coolness for the bank of the Mississippi River as it flows by the University of Minnesota Twin Cities campus.

The three men send a bucket splashing into the current and haul back a water sample. That doesn’t affect the river much, but information locked away in bacteria from the sample may tell them a great deal about how the river’s microbial communities change along its course through Minnesota and how human activity affects them. (more…)

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Ceramics Tell the Story of an Ancient Southwest Migration

Another look at a nearly 80-year-old pottery collection at the Arizona State Museum is yielding new information about migrants who abandoned the Four Corners region.

Approximately eight centuries ago, people living along the Colorado Plateau in what is now the Four Corners area faced a crisis. Environmental changes that devastated their agricultural practices and likely aggravated social unrest forced significant numbers of these people to move away.

Many of them headed south into central and southern Arizona and western New Mexico, into lands already inhabited by well-established groups.

What is remarkable about this diaspora is that while there is no written record of what happened, much of what archaeologists know is told in the ceramic bowls, plates and figurines that were created and left behind when those civilizations later collapsed. (more…)

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Landslides Linked to Plate Tectonics Create the Steepest Mountain Terrain

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…)

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Mather Lecture

Renowned expert Charles J. Vörösmarty addresses global water crisis

The world’s streams, rivers and lakes are under increasing stress because of human water management – and mismanagement – that threaten aquatic biodiversity and the water supply, Charles J. Vörösmarty said recently during the second annual John R. Mather Visiting Scholars Lecture.

Vörösmarty, professor of civil engineering with the City College of New York, presented “Global Water Crisis: The Slippery Slope” on May 3 at the University of Delaware’s Roselle Center for the Arts.

“The contemporary water system is really defined increasingly by the actions of humans,” he said. (more…)

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Green-Glowing Fish Provides New Insights into Health Impacts of Pollution

Understanding the damage that pollution causes to both wildlife and human health is set to become much easier thanks to a new green-glowing zebrafish.

Created by a team from the University of Exeter, the fish makes it easier than ever before to see where in the body environmental chemicals act and how they affect health.

The fluorescent fish has shown that oestrogenic chemicals, which are already linked to reproductive problems, impact on more parts of the body than previously thought.

The research by the University of Exeter and UCL (University College London) is published in the journal Environmental Health Perspectives. (more…)

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Sediment Sleuthing

Radioactive medicine being tracked through rivers

A University of Delaware oceanographer has stumbled upon an unusual aid for studying local waterways: radioactive iodine. Trace amounts of the contaminant, which is used in medical treatments, are entering waterways via wastewater treatment systems and providing a new way to track where and how substances travel through rivers to the ocean.

“This is a really interesting convergence of medicine, public health and environmental science,” said Christopher Sommerfield, associate professor of oceanography in UD’s College of Earth, Ocean, and Environment. (more…)

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