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timothy oleson

Secondary aerosols a primary cause of Chinese smog

Images of Chinese skylines and streetscapes blurred by pollution-fueled hazes have become increasingly common in recent years amid ongoing urbanization and industrialization. According to a new study published in Nature, much of the pollution fogging the country’s major cities is arising not from fine particles emitted directly into the sky, but by gases that react and condense in the atmosphere to form secondary aerosols.

24 Jan 2015

Red Planet Roundup: January 2015

As two rovers patrol the surface of Mars, five spacecraft orbit above and scientists back here on Earth study the Red Planet from afar, new findings are announced almost weekly. Here are a few of the latest updates.

15 Jan 2015

The '100-year flood' fallacy: Return periods misleading in communication of flood risk

The “100-year flood” is a familiar term to anyone who lives in a flood-prone area or has ever looked at a flood map before buying homeowner’s insurance. Return periods, or recurrence intervals, like this are standard parlance for describing the magnitude and potential hazard of floods, as well as other hydrologic events like storms and droughts. Although such terms have long helped policymakers and the public try to make sense of severe weather, one researcher suggests they may confuse the issue more than clarify it.

11 Jan 2015

Skinned oceanic plates may be origin of ophiolites

Long recognized as slivers of oceanic crust incongruously emplaced on land, ophiolites are distinctive sequences of basalt, gabbro and peridotite found globally near former and current convergent zones, where oceanic tectonic plates subduct under continents. But scientists don’t have a clear idea why or how ophiolites split from downgoing plates and find their way onto land. Now, a new study suggests part of the answer may relate to weak layers of mantle that allow oceanic crust to be peeled, or “skinned,” from subducting slabs as they descend.
 

10 Jan 2015

Utah gravity slide was one for the record books

When Washington state’s Mount St. Helens erupted in 1980, the volcano’s northern flank gave way, sending about 2.5 cubic kilometers of material down its slopes and into nearby valleys in what was the largest debris avalanche in recorded history. But roughly 22 million years earlier, one of the largest-known volcanic landslides the world has ever seen occurred in southwestern Utah, according to a study in Geology. That one, estimate the study’s authors, released between 1,700 and 2,000 cubic kilometers of ash, tuff and sandstone — nearly 1,000 times as much as Mount St. Helens — over a 3,400-square-kilometer area.

09 Jan 2015

Lead-up to Icelandic earthquakes seen in groundwater chemistry

Scientists tracking groundwater in Iceland have reported that significant shifts in the water’s chemistry occurred months prior to earthquakes in 2012 and 2013. It’s far too early to apply the findings to earthquake hazard assessment, researchers say, but the results suggest that precursory groundwater changes may also herald earthquakes elsewhere and point toward a potential means of future seismic monitoring.

31 Dec 2014

Ice (Re) Cap: December 2014

From Antarctica to the Arctic; from polar caps, permafrost and glaciers to ocean-rafted sea ice; and from burly bears to cold-loving microbes, fascinating science is found in every nook and crevasse of Earth’s cryosphere, and new findings are announced often. Here are a few of the latest updates.

30 Dec 2014

Oil-encased water droplets are mini-ecosystems for microbes

Dark, sludgy oil may not seem like an environment suited to life. But microbes, known to make meals of such organic stews by breaking down large hydrocarbons to extract food and energy, have been found before in petroleum reservoirs. Now, in a new study, researchers report finding diverse communities of microorganisms living inside tiny water droplets in Pitch Lake, the world’s largest natural asphalt seep located on the Caribbean island of Trinidad. The discovery may have implications for industry, scientists say, as well as for our understanding of extreme life.

30 Dec 2014

Rainwater penetrates into ductile crust

Rainwater is capable of percolating deeper into Earth’s crust than once thought possible, according to a new study. The finding could impact our understanding of mountain building, the behavior of rock deep underground and the formation of hydrothermal mineral deposits.

27 Dec 2014

Nanoflares power the sun's superheated corona

The sun’s outer atmosphere, or corona, reaches temperatures of more than 1 million degrees Celsius, hundreds of times hotter than its visible surface. The reason for this has puzzled scientists, who so far have only been able to theorize explanations.

24 Dec 2014

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