NATURE
1. Melting ice spurs wild weather
Nature 504, 190 (12 December 2013) doi: 10.1038/504190c
Arctic sea-ice retreat and, to a lesser degree, decreased snow cover were found to alter large-scale atmospheric circulation patterns. These typically cause heatwaves and other extreme weather events at mid-latitudes.
2. Life possible in the early Universe
Zeeya Merali
Nature 504, 201 (12 December 2013) doi: 10.1038/504201a
The energy required to keep water liquid in the early Universe could have come from the cosmic microwave background, the afterglow of the Big Bang, rather than from host stars. A habitable epoch of 2 to 3 million years was proposed, during which all rocky planets would have been able to maintain liquid water regardless of their distance from a star.
3. Gas production contaminates water
Nature 504, 191 (12 December 2013) doi: 10.1038/504191f
Environ. Sci. Technol. 47, 11849-11857 (2013)
Wastewater from oil and gas production has been shown to cause an increase in contaminants, such as chloride and radium, in surface waters and sediments in Western Pennsylvania.
4. Food fuelled with fungi
Nicola Jones
Nature 504, 199 (12 December 2013) doi: 10.1038/504199a
Researchers have harnessed the symbiotic relationship endophytes have with plants to improve crop yield and reduce water use.
SCIENCE
5. New results send Mars rover on a quest for ancient life
Richard A. Kerr
Vol. 342 no. 6164 pp. 1300-1301 doi: 10.1126/science.342.6164.1300
Lakebed samples from Mars may indicate organic carbon content. The Curiosity rover has also determined how recently surface rocks have been exposed by erosion, opening the way to more systematic searches for molecular fossils by showing scientists how to maximise chances of finding organic matter that has only recently been exposed to cosmic rays.
6. Europe readies peerless star mapper
Daniel Clery
Vol. 342 no. 6164 p. 1305 doi: 10.1126/science.342.6164.1305
Gaia will map the positions and motions of stars in the Milky Way with 200 times the accuracy of Hipparcos, its predecessor in the early 1990s.
GEOLOGY
7. Riverine mixing and fluvial iron formation: A new type of Precambrian biochemical sediment
Peir K. Pufahl, Franco Pirajno & Eric. E. Hiatt
Vol. 41 no. 12 p. 1235-1238 doi: 10.1130/G34812.1
Fluvial iron formation is a new type of Fe-rich microbial-biochemical sediment that formed by mixing river discharge and seawater in coastal environments. Because these precipitated at the interface between terrestrial and marine realms instead of typically marine settings, they may allow further research into ocean-atmosphere evolution.
8. Subduction and deformation of the continental lithosphere in response to plate and crust-mantle coupling
E. Willingshofer, D. Sokoutis, S. W. Luth, F. Beekman & S. Cloetingh
Vol. 41 no. 12 p. 1239-1242 doi: 10.1130/G34815.1
Experimental results show subduction of slabs is deepest in cases with strong decoupling at the plate interface and at the level of the lower crust of the downgoing plate, with upper-plate deformation restricted to the area close to the plate contact. The degree of plate coupling determines the efficiency of subduction of continental lithosphere under conditions of collision of neutrally buoyant lithospheres. The results explain the geometry and sequence of deformation in subduction-dominated orogens, such as the Carpathians or the Dinarides.
9. Glacier slip and seismicity induced by surface melt
Peter L. Moore, J. Paul Winberry, Neal R. Iverson, Knut A. Christianson, Sridhar Anandakrishnan, Miriam Jackson, Mark E. Mathison & Denis Cohen
Vol. 41 no. 12 p. 1247-1250 doi: 10.1130/G34760.1
Direct measurements of basal hydrology, sliding and broadband seismicity were obtained in a unique subglacial facility in Norway. In the most pronounced episode, rapid delivery of surface meltwater to the bed briefly enhanced basal slip following a period of elevated high-frequency seismic activity related to surface crevassing. The results support theoretical models for hydraulic jacking and illustrate how melt-induced increases in speed can be short-lived if cavity growth or ice-bed decoupling allows basal water more efficient drainage.
NATURE COMMUNICATIONS
10. Increases in terrestrially derived carbon stimulate organic carbon processing and CO2 emissions in boreal aquatic ecosystems
Jean-Francois Lapierre, Francois Guillemette, Martin Berggren & Paul A. del Giorgio
Nature Communications 4, 2972 (2013) doi: 10.1038/ncomms3972
Via the analysis of hundreds of boreal lakes, rivers and wetlands in Canada, the proportion of biologically degradable dissolved organic carbon was shown to remain constant and the photochemical degradability to increase with terrestrial influence. There is thus a strong causal link between dissolved organic carbon concentrations and aquatic fluxes of carbon dioxide, mediated by the degradation of land-derived organic carbon in aquatic ecosystems.
