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Volcanic lightning turns ash into glass

Within the ash plumes of explosive volcanic eruptions, collisions among countless pyroclastic particles sometimes lead to the buildup of static charges that discharge dramatically as volcanic lightning. In a new study, researchers have found that this lightning can, in turn, melt and fuse ash particles into distinctive glassy grains called spherules.

07 Aug 2015

Beached iceberg alters Antarctic marine communities

Studying the effects of expanding sea ice around Antarctica has been challenging, however, as it is difficult to predict exactly where sea ice will expand and whether it will stick around long enough to make a difference on marine life. But a rare event involving an iceberg bigger than the island of Manhattan created just the environment that Graeme Clark, an ecologist at the University of New South Wales in Australia, and his colleagues needed to study how the sudden advent of long-term sea-ice cover affects marine communities.

21 Jul 2015

Brachiopod die-off signaled mid-Permian mass extinction

Since the explosion of complex lifeforms before the turn of the Cambrian, the expansion of life on Earth has been punctuated by a quintet of global mass extinctions known as the “Big Five.” The biggest of these happened toward the end of the Permian Period about 252 million years ago, when 95 percent of all species went extinct. In a new study, scientists have proposed that a sixth global extinction, about 10 million years before the End-Permian die-off, should be added to the list.

16 Jul 2015

Aquifers contaminated by Supertyphoon Haiyan storm surge

Supertyphoon Haiyan, which battered the Philippines in November 2013, was the most powerful hurricane to make landfall ever recorded. A new study has quantified damage done by the resulting storm surge to the fragile coastal aquifers that residents of one town rely on, and how long it might take for the aquifers to recover.

09 Jul 2015

California's big trees dying of thirst

From the days of John Muir’s treks through the valleys and peaks of the Sierra Nevada, California’s majestic forests have attracted nature lovers from around the world. Since Muir’s death in 1914, though, dramatic changes have taken hold. Across the state’s forests, small trees are more common while large trees have declined in number, and oaks seem to be taking over where pines once ruled. A new study cites drought due to warming as a major driving force behind these changes.

29 May 2015

Megafloods mostly shaped Icelandic canyon landscape

A new study suggests that in one environment prone to catastrophic floods, the Jökulsárgljúfur Canyon in northeastern Iceland, the effects of several megafloods in the past 9,000 years have sculpted the canyon landscape far more so than “background” erosion caused by water and sediment flowing through it.

22 May 2015

Shrinking snowpack projected in western U.S. as rain-snow boundary climbs higher

Gauging the impacts of climate change on future precipitation is challenging, especially in the western U.S., a region with highly variable temperatures, precipitation patterns and terrain. But understanding such impacts in the West — and, in particular, how much precipitation will fall as snow versus rain in the future — is important given the region’s dependence on wintertime snowfall as a freshwater resource. Now, a new study forecasts a broad shift from snow to rain for much of the West — a projection that will require attention from land and water resource managers planning for the future.

24 Apr 2015

Wedge approach proposed to lower water stress

Roughly 30 percent of the global population — or about 2.2 billion people — lives in water-stressed parts of the world, where high freshwater withdrawals endanger ecosystems, agriculture and drinking-water supplies. If current population and water usage trends persist, this fraction could rise to about one-half by the century’s end. In a recent study, researchers — taking a page from the climate-change mitigation literature — have proposed a “wedge” approach to address global water stress, laying out how various tactics could ease the growing problem.

22 Apr 2015

Some coral reefs bounce back after bleaching

Ocean temperatures that rise too much or for too long can harm coral reefs, sometimes causing mass die-offs that leave reefs nearly barren of live corals. But scientists don’t know if or under what conditions reefs can recover from such catastrophes. Now, a new study suggests that, given time and the right conditions, even once-decimated reefs can recoup their losses.

09 Apr 2015

Twentieth-century warming linked to Pacific trade winds

Earth’s average atmospheric temperature warmed by about 1.3 degrees Celsius over the course of the 20th century. However, the rate of increase during that time was not constant and scientists have been unable to fully explain the timing and pattern of warming. Now, a recent study has identified a correlation between global temperatures and the strength of Pacific trade winds that may help clear up the some of the confusion.

13 Mar 2015

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