Earth

Newly discovered mechanism propels micromotors

WASHINGTON, D.C. Oct. 15, 2013 -- Scientists studying the behavior of platinum particles immersed in hydrogen peroxide may have discovered a new way to propel microscopic machines. The new mechanism is described in The Journal of Chemical Physics, which is produced by AIP Publishing.

First evidence that dust and sand deposits in China are controlled by rivers

New research published today in the journal Quaternary Science Reviews has found the first evidence that large rivers control desert sands and dust in Northern China.

Northern China holds some of the world's most significant wind-blown dust deposits, known as loess. The origin of this loess-forming dust and its relationship to sand has previously been the subject of considerable debate.

Crystals in Picabo's rocks point to 'recycled' super-volcanic magma chambers

EUGENE, Ore. -- (Oct. 11, 2013) -- A thorough examination of tiny crystals of zircon, a mineral found in rhyolites, an igneous rock, from the Snake River Plain has solidified evidence for a new way of looking at the life cycle of super-volcanic eruptions in the long track of the Yellowstone hotspot, say University of Oregon scientists.

Unregulated, agricultural ammonia threatens national parks' ecology

Cambridge, Mass. – October 10, 2013 – Thirty-eight U.S. national parks are experiencing "accidental fertilization" at or above a critical threshold for ecological damage, according to a study published in the journal Atmospheric Chemistry and Physics and led by Harvard University researchers. Unless significant controls on ammonia emissions are introduced at a national level, they say, little improvement is likely between now and 2050.

Rice University mix of graphene nanoribbons, polymer has potential for cars, soda, beer

A discovery at Rice University aims to make vehicles that run on compressed natural gas more practical. It might also prolong the shelf life of bottled beer and soda.

The Rice lab of chemist James Tour has enhanced a polymer material to make it far more impermeable to pressurized gas and far lighter than the metal in tanks now used to contain the gas.

The combination could be a boon for an auto industry under pressure to market consumer cars that use cheaper natural gas. It could also find a market in food and beverage packaging.

Iron in the Earth's core weakens before melting

The iron in the Earth's inner core weakens dramatically before it melts, explaining the unusual properties that exist in the moon-sized solid centre of our planet that have, up until now, been difficult to understand.

Scientists use seismic waves - pulses of energy generated during earthquakes - to measure what is happening in the Earth's inner core, which at 6000 km beneath our feet is completely inaccessible.

U of M researchers suggest complex relationship between phosphorus levels and nitrogen removal in lakes

In the land of 10,000 lakes, one lake has been the starting place for research with implications for big lakes around the world. According to a study published online this week in Science, University of Minnesota researchers, building from studies of nitrogen levels in Lake Superior, uncovered a good news/bad news scenario for lake health that has long-term, global implications for pollution control efforts.

'Stadium waves' could explain lull in global warming

One of the most controversial issues emerging from the recent Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) is the failure of global climate models to predict a hiatus in warming of global surface temperatures since 1998. Several ideas have been put forward to explain this hiatus, including what the IPCC refers to as 'unpredictable climate variability' that is associated with large-scale circulation regimes in the atmosphere and ocean. The most familiar of these regimes is El Niño/La Niña, which are parts of an oscillation in the ocean-atmosphere system.

3D model reveals new information about iconic volcano

The volcano on the Scottish peninsula Ardnamurchan is a popular place for the study of rocks and structures in the core of a volcano. Geology students read about it in text books and geologists have been certain that the Ardnamurchan volcano have three successive magma chambers. However, an international group of researchers, lead from Uppsala University, Sweden, has now showed that the volcano only has one single magma chamber.

The new study is published in Scientific Reports, the new open access journal of the Nature Publishing Group.

Water impurities key to an icicle's ripples

A group of physicists from Canada have been growing their own icicles in a lab in the hope of solving a mystery that has, up until now, continued to puzzle scientists.

The presence of characteristic ripples along the surface of icicles, which remarkably have the same wavelength no matter how big the icicle or where in the world it grows, have led to several studies examining exactly how the ripples form.

Want ripples on your icicles? University of Toronto scientists suggest adding salt

Morris and Chen found that ripples only became apparent at the remarkably low salinity of the water with 20 mg of salt per litre. This level, in fact, is a considerably lower level of impurity than found in common tap water.

"We even added a non-ionic ingredient to the distilled water to reduce the surface tension of the thin film of water flowing over the icicle, and it didn't produce ripples," said Chen. "Instead, ripples emerge only on icicles grown from water with dissolved ionic impurities."

Carbon's new champion

HOUSTON – (Oct. 9, 2013) – Carbyne will be the strongest of a new class of microscopic materials if and when anyone can make it in bulk.

If they do, they'll find carbyne nanorods or nanoropes have a host of remarkable and useful properties, as described in a new paper by Rice University theoretical physicist Boris Yakobson and his group. The paper appears this week in the American Chemical Society journal ACS Nano.

Geoscience Currents No. 78

Alexandria, VA – An important question asked of recent graduates with geoscience majors is why they chose to major in the earth sciences. Recent analysis of over 400 responses from the National Geoscience Student Exit Survey from 71 geoscience departments identified several common answers among the respondents. Of those surveyed, many declared a geoscience major during their formative undergraduate years for a variety of reasons: enjoyment working in the outdoors, a lifelong interest in the subject and desire for career opportunities are among some of the most common.

Study in Nature reveals urgent new time frame for climate change

Ecological and societal disruptions by modern climate change are critically determined by the time frame over which climates shift. Camilo Mora and colleagues in the College of Social Sciences' Department of Geography at the University of Hawaii, Manoa have developed one such time frame.

Evidence for a new nuclear 'magic number'

Researchers have come one step closer to understanding unstable atomic nuclei. A team of researchers from RIKEN, the University of Tokyo and other institutions in Japan and Italy has provided evidence for a new nuclear magic number in the unstable, radioactive calcium isotope 54Ca. In a study published today in the journal Nature, they show that 54Ca is the first known nucleus with 34 neutrons (N) where N = 34 is a magic number.