Taxonomy term

sediment

Western wildfires affect water quality

Wildfires have burned increasing acreage in recent decades, a trend that’s expected to continue with global climate change. In the U.S. West, the frequency of fires has implications for water availability — both water used to fight wildfires and municipal water supplies, which can be contaminated by loosened debris from eroding, fire-burned slopes.

09 Jan 2018

Pharmaceuticals in urban sediments reveal wastewater treatment effectiveness

People take pills to relieve headaches or syrups to ease a hacking cough, and eventually these medications can make their way into streams and rivers around the world as humans excrete the chemicals. Scientists are now using concentrations of common pharmaceutical products (PPs) in river sediments in Orléans, France, to determine how effective four water treatment plants have been at removing chemicals from the environment.

03 Nov 2017

Neolithic farmers impacted sedimentation

The Neolithic Revolution, also known as the Agricultural Revolution, started in the Middle East about 11,500 years ago when people moved away from nomadic hunting and gathering toward more settled agricultural communities where they raised livestock and cultivated crops. In a new study of the Dead Sea Basin, researchers found that this turning point may also mark the first time that humans made a measurable impact on sedimentation rates.

29 Sep 2017

Dehydrated sediment layer made Sumatra quake stronger

Subduction zones are notorious for unleashing great earthquakes and tsunamis, such as the 2004 magnitude-9.1 Sumatra quake that caused shaking and inundations that killed more than 250,000 people and left millions more homeless. However, despite the dangerous reputations of subduction zones, their hazards are still often underestimated. New research reveals how sediments in the Sumatra Trench may have contributed to producing an even bigger earthquake and tsunami than hazard forecasts had estimated.

07 Sep 2017

Whirling "gravel devils" show wind can carry more than just sand

Sand grains, by definition, are between 0.06 and 2 millimeters in diameter, and they are often thought of by scientists as the largest sediments that wind can transport, with larger sediments simply being too hefty for winds to keep aloft. But strong winds, particularly in tropical storms and tornadoes, are known to move objects far larger than sand over short distances. Now, in the high Andes of Chile on the Salar Gorbea salt flat, evidence has been found of tornadic “gravel devils” whipping across the landscape and transporting gypsum crystals as long as 27 centimeters.

16 Jun 2017

Red Planet Roundup: April 2017

With two rovers patrolling the surface of Mars, six spacecraft orbiting above it, and scientists here on Earth studying the Red Planet from afar, new findings are announced often. Here are a few of the latest updates.

 
14 Apr 2017

Supernova explosion detected in Early Pleistocene sediments

When a massive star comes to the end of its life cycle, it goes out with a spectacular bang known as a supernova. Only three of these events have been observed in the Milky Way in the past 1,000 years. Evidence for older explosions can be detected in the form of rare elements found on Earth that are only produced by such explosions.

10 Jan 2017

Frosted forams foil radiocarbon dating

Climate studies often rely on radiocarbon dating of tiny shells in seafloor sediments to pinpoint the timing of when warming or cooling events began and ended. But a new study indicates that chemical reactions that take place on the seafloor may affect the accuracy of such radiocarbon dates, with potential implications for the dates published by past studies

01 Nov 2016

Dating of landslides around Oso reveals recurring patterns

On March 22, 2014, after a period of heavy rain, a hillside near the town of Oso, Wash., collapsed, sending 7.6 million cubic meters of mud and debris across the North Fork of the Stillaguamish River, destroying a rural neighborhood and killing 43 people. The slide took Oso residents by surprise, but scientists say the event was not altogether unexpected, as evidence for dozens of past landslides can be found throughout the Stillaguamish River Valley. New research suggests that large slides have occurred in the Oso vicinity even more frequently than previously suspected.

07 Jun 2016

Lake sediments suggest mild volcanic winter after massive Toba eruption

Roughly 74,000 years ago, the largest volcanic eruption of at least the last 2.5 million years — and possibly the last 27 million years — spewed as much as 5,000 cubic kilometers of magma and ash, the latter of which spread far and wide from the source. This catastrophic eruption of the Toba supervolcano on the Indonesian island of Sumatra has long been suggested as a trigger for a precipitous period of global cooling known as a “volcanic winter” that in turn might have driven early humans to the brink of extinction. In a new study, researchers dispute these notions, concluding from an analysis of climate-sensitive microfossils preserved in lake sediments in East Africa — the ancestral home of early humans — that the region experienced little or no cooling following the massive eruption. 
 
10 Jan 2016

Pages