Taxonomy term

geology

Beavers preserve wetlands in water-stressed areas

Once considered detrimental to ecosystems and nuisances where, for example, dams flooded farmland, beavers have been rhetorically touted in recent years as a potential boon for wetland health and water conservation. Anecdotal accounts and qualitative findings have suggested beavers improve water quality and availability in drought-stressed ecosystems, but just how much influence they have was not known. In new research, scientists have examined two creeks in Nevada to directly measure how effective beaver dams are at slowing water flows and storing water through the dry summer months.

30 Jan 2018

Congress mulls options for abandoned mines legislation

Amid the well-publicized discussions over healthcare, tax reform, the federal budget and disaster aid in summer and fall 2017, a quieter conversation over mining legislation reform was also going on in Congress. Democrats and Republicans in both chambers introduced legislation concerning abandoned mine lands (AML) in the current congres­sional session, and while no new bills have been passed, discussions continue on the contentious subject.

29 Jan 2018

Benchmarks: January 25, 1968: The last firefall: A Yosemite tradition flames out

Fifty years ago this month, on Jan. 25, 1968, a massive bonfire built of red fir bark atop Glacier Point in Yosemite National Park was burned down to embers and, promptly at 9 p.m., and for the last time, pushed over the cliff edge to create a flaming cascade for the viewing enjoyment of tourists gathered below. The spectacle, called “firefall,” had been a beloved Yosemite tradition for nearly a century.

25 Jan 2018

Unexpected nanoparticles trace coal pollution

Coal burning produces an array of chemicals and particulates that, when released into the atmosphere, contribute to pollution, poor air quality and threats to public health. Measurements of particulate air pollution typically focus on particles called PM2.5, which have diameters of 2.5 micrometers or less. This group includes nano-sized particles, although these bits of minerals, dust and organics often go undetected because of their tiny size. In a new study, researchers sampling a coal ash spill have unearthed a type of nanoparticle not previously known to be produced by burning coal. While the particles might be useful in detecting pollution problems, they may also have consequences for human and environmental health.

24 Jan 2018

No river meant no floods for ancient Indus settlements

Large Middle Eastern rivers like the Nile, Tigris, Euphrates and Tiber were critical for the development of early urban societies in Egypt, Mesopotamia and Ancient Rome. And researchers have long thought that the rise, and eventual decline, of cities in the ancient Indus Civilization, which spread across about 1 million square kilometers of what’s now northwestern India and Pakistan from roughly 4,600 to 3,900 years ago, also depended on major rivers, namely those emerging from the Himalayas. But a new study looking at river sediments from the time of the civilization and earlier suggests that wasn’t the case for every ancient Indus city; some may have benefited from being farther away from large rivers and their periodic floods.

23 Jan 2018

Dividing line: The past, present and future of the 100th Meridian

In 1878, John Wesley Powell first advanced the idea that the climatic boundary between the United States’ humid East and arid West lay along the 100th meridian, which
runs from pole to pole and, today, cuts through six U.S. states. But what does it really mean, and what is its future?
22 Jan 2018

Down to Earth With: Wildfire meteorologist Craig Clements

Not many people are able to combine their work and hobbies the way Craig Clements, a meteorologist at San Jose State University in California, has. “I was always interested in mountain weather,” he says. “I got into meteorology through my interest in mountaineering and climbing.”

19 Jan 2018

Mediterranean tsunami record may be overreported

Tsunamis are one of the most destructive natural hazards on Earth, sometimes even upstaging the major earthquakes that send the waves surging across entire ocean basins. Knowing when, where and how severely tsunamis have struck coastlines in the past is valuable for countries trying to prepare for the impacts of future tsunamis. But distinguishing tsunami deposits in geologic paleorecords from deposits left by more common storm waves is notoriously difficult. Researchers recently highlighted this challenge by taking a hard look at tsunami- and storm-wave records around the Mediterranean Sea over the last 4,500 years. The findings may serve as a cautionary tale for scientists interpreting tsunami records elsewhere in the world.

18 Jan 2018

Mediterranean drawdown may have caused burst of volcanism

Between 5 million and 6 million years ago, during an event known as the Messinian Salinity Crisis (MSC), large amounts of seawater evaporated from the Mediterranean Sea leaving massive salt deposits in the basin. How much the sea surface dropped during the MSC is debated, but in a new study in Nature Geoscience, researchers suggest that a large, kilometer-scale drawdown of the Mediterranean Sea may explain not just the thick salt deposits but also a pulse of magmatic activity around the region that occurred at the same time as the MSC.

17 Jan 2018

Small warm ponds: Ideal incubators for first life?

The first embers of life are thought to have emerged on Earth between 4.5 billion and 3.7 billion years ago, but how and where the initial sparks arose remains a mystery. Two leading theories suggest that the first self-replicating molecules — a necessity for life — may have gotten a start either in deep-ocean hydrothermal vents or in small warm ponds on land. In a new study, researchers suggest that the wet-dry cycles occurring in small, seasonal ponds would have made a better natural incubator.

17 Jan 2018

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