The collision between the Siberian Plate and North China Plate was a significant geological event in earth history, which led to the final closure of the Paleoasian Ocean and the formation of the Eurasian continent. Despite numerous research efforts in recent decades, the precise time of this event has remained a puzzle until now. New evidence in helping settle this issue is provided by Prof. Deng Shenghui and his colleagues in their paper newly published in Science in China (2009, vol.52).
Earth
An international team of scientists led by researchers at the University of Hawaii at Manoa have found no evidence supporting an extraterrestrial impact event at the onset of the Younger Dryas ~13000 years ago.
Carbon dioxide (CO2) is the most important greenhouse gas regulated by the Kyoto Protocol. Human activities, such as fossil fuel burning and land use change, are major emitters of CO2, which is widely recognized as drivers of global warming and climate change. In the past decades, the field campaign and research program were only conducted at a few sites in China by different agencies.
As physicists strive to cool atoms down to ever more frigid temperatures, they face the daunting task of developing new, reliable ways of measuring these extreme lows. Now a team of physicists has devised a thermometer that can potentially measure temperatures as low as tens of trillionths of a degree above absolute zero. Their experiment is reported in the current issue of Physical Review Letters and highlighted with a Viewpoint in the December 7 issue of Physics (http://physics.aps.org.)
GAINESVILLE, Fla. — New information about lightning-emitted X-rays, gamma rays and high-energy electrons during thunderstorms is prompting scientists to raise concerns about the potential for airline passengers and crews to be exposed to harmful levels of radiation.
WEST LAFAYETTE, Ind. - There is more to the snowflake than its ability to delight schoolchildren and snarl traffic.
The structure of the frosty flakes also fascinate ice chemists like Purdue University's Travis Knepp, a doctoral candidate in analytical chemistry who studies the basics of snowflake structure to gain more insight into the dynamics of ground-level, or "tropospheric," ozone depletion in the Arctic.
New high-energy particle research by a team working with data from Fermi National Accelerator Laboratory further heightens the uncertainty about the exact nature of a key theoretical component of modern physics — the massive fundamental particle called the Higgs boson.
Very often in science, the unexpected discovery turns out to be the most significant. Rice University Professor Junichiro Kono and his team weren't looking for a breakthrough in the transmission of terahertz signals, but there it was: a plasmonic material that would, with adjustments to its temperature and/or magnetic field, either stop a terahertz beam cold or let it pass completely.
In the long term, the Earth's temperature may be 30-50% more sensitive to atmospheric carbon dioxide than has previously been estimated, reports a new study published in Nature Geoscience this week.
The results show that components of the Earth's climate system that vary over long timescales – such as land-ice and vegetation – have an important effect on this temperature sensitivity, but these factors are often neglected in current climate models.
Some atoms don't always follow the rules.
Take the beryllium dimer, a seemingly simple molecule made up of two atoms that University of Delaware physicists Krzysztof Szalewicz and Konrad Patkowski and colleague Vladimír Spirko of the Academy of Sciences of the Czech Republic report on in the Dec. 4 edition of the journal Science.
A new study by an international research team has opened up a window into the earth to reveal Hawaii's deep roots and the best picture yet of a plume originating from the lower mantle. The findings suggest that the Hawaiian hot spot is the result of an upwelling high-temperature plume from the lower mantle.
December 4, 2009 -- Most earthquakes occur along fault lines, which form boundaries between two tectonic plates. As the relative speed of the plates around a fault increases, is there a corresponding increase in the number of earthquakes produced along the fault? According to this study published in the December issue of BSSA, the answer depends upon the type of tectonic boundary. On certain types of boundary, the efficiency of earthquake production actually depends on the fault slip rate.
MADISON — The rising level of atmospheric carbon dioxide may be fueling more than climate change. It could also be making some trees grow like crazy.
The third in a series of papers in the journal Nature completes the case for a new method of predicting earthquakes.
The forecasting model developed by Danijel Schorlemmer, of the USC College of Letters, Arts and Sciences, aims to predict the rough size and location of future quakes. Testing of the model is underway.
While the timing of quakes remains unpredictable, progress on two out of three key questions is significant in the hard discipline of earthquake forecasting.