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timothy oleson

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

Bare Earth Elements: Past and present directors dissect the future of USGS

The U.S. Geological Survey, including its employees and leadership, have a penchant for self-assessment and an ambition for pragmatic self-improvement. That was on display Thursday, Dec. 18, in San Francisco in an hour-long panel discussion held in conjunction with the annual fall meeting of the American Geophysical Union, and featuring USGS acting director Suzette Kimball along with four of the five most recent past directors and acting directors. The panelists candidly addressed a number of issues, including how USGS has been and should continue adapting to best address its roles in science and public service, as well as internal and external barriers affecting its success in these roles.

22 Dec 2014

Carbon tet still offensive to ozone layer

Earth’s ultraviolet light-shielding ozone layer is recovering, according to a report released in September by the World Meteorological Organization and the United Nations Environment Programme. The findings, authored by more than 250 scientists and presented as part of the latest Scientific Assessment of Ozone Depletion (SAOD), suggest the ongoing success of the 1987 Montreal Protocol and its amendments in cutting atmospheric levels of chlorofluorocarbons (CFCs) and other ozone-depleting substances (ODS’s), which have fallen by about 10 to 15 percent overall since peaking in the late 1990s.

22 Dec 2014

Last Scottish glacier melted during big chill?

Scotland’s craggy peaks, deep lochs and fjord-lined coast are hallmarks of a landscape shaped by successive glaciations, the last of which, toward the end of the Pleistocene, draped the highlands with an ice cap covering 9,500 square kilometers. Rocky moraines give scientists a clear picture of the boundaries of this glaciation, called the Loch Lomond Advance, although the timeline of its growth and eventual demise has proved difficult to pin down.

18 Dec 2014

Limited ranges left ammonites vulnerable to extinction

Why spiral-shelled, ocean-faring ammonites went extinct at the end of the Cretaceous while the nautilids — the ammonites’ less abundant and less diverse cephalopod relatives — survived has long puzzled paleontologists. Nautilids tended to dwell deeper in the ocean than ammonites, perhaps keeping them farther out of harm’s way after the asteroid struck, which likely led to acidification of the ocean surface. Now, a new study suggests that the animals’ geographic range may have contributed to which ones lived and which ones died.

13 Dec 2014

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