NATURE
1. China plunges into ocean research
Nature 506, 276 (20 February 2014) doi: 10.1038/506276a
China has embarked on a five-year research project called the Western Pacific Ocean System (WPOS) and it will deploy five ships, a remotely operated submersible and an array of sub-surface moorings off the eastern coasts of Philippines and Indonesia to investigate the western Pacific warm pool and the Kuroshio current.
2. Conservation: Nicaragua Canal could wreak environmental ruin
Axel Meyer & Jorge A. Huete-Perez
Nature 506, 287-289 (20 February 2014) doi: 10.1038/506287a
A planned 300-kilometre waterway joining the Pacific and Atlantic oceans could result in destruction of around 400 000 hectares of rainforests and wetlands and subsequently endanger ecosystems. Independent environmental assessment should be carried out before any construction is to take place.
3. Prodigious degassing of a billion years of accumulated radiogenic helium at Yellowstone
J. B. Lowenstern, W. C. Evans, D. Bergfeld & A. G. Hunt
Nature 506, 355-358 (20 February 2014) doi: 10.1038/nature12992
The authors combine gas emission rates with chemistry and isotopic analyses to show that crustal helium-4 emission rates from Yellowstone exceed crustal generation rates. This implies that helium has accumulated in Archaean cratonic rocks beneath Yellowstone only to be liberated over the past two million years by intense crustal metamorphism induced by the Yellowstone hotspot.
SCIENCE
4. Atlantic current can shut down for centuries, disrupting climate
Richard A. Kerr
Vol. 343 no. 6173 p. 831 doi:10.1126/science.343.6173.831
Using an epibenthic foraminiferal δ13C record, researchers showed that North Atlantic Deep Water influence was strong at the onset of the last interglacial period and then interrupted by several prominent, centennial-scale reductions. These occurred during periods of increased ice rafting and southward expansions of polar water influence, suggesting a buoyancy threshold for convective instability was triggered by freshwater and circum-Arctic cryosphere changes. The vulnerability of the Atlantic circulation may have a huge impact on future climate.
5. From past to future warming
Gabi Hegerl & Peter Stott
Vol. 343 no. 6173 pp. 844-845 doi: 10.1126/science.1249368
According to the IPCC Fifth Assessment Report, anthropogenic influence on Earth climate is ‘extremely likely’ to cause more than half of the observed increase in global average temperature from 1951 to 2010. However, the uncertainty in the estimated contribution of greenhouse gases to the observed global-mean warming is still large. Data gaps and other variables may mask the reality and cause inaccuracies in models.
NATURE GEOSCIENCE
6. Saharan lake
Amy Whitchurch
Nature Geoscience 7, 82 (2014) doi: 10.1038/ngeo2089
Beryllium-10 isotope dating was used to date palaeolake shoreline deposits preserved in Sudan, eastern Sahara to about 109 000 years. The lake probably formed during the last interglacial period and was broadly similar in surface area to today’s largest freshwater lakes.
7. Extensive liquid meltwater storage in firn within the Greenland ice sheet
Richard R. Forster, Jason E. Box, Michiel R. van den Broeke, Clément Miège, Evan W. Burgess, Jan H. van Angelen, Jan T. M. Lenaerts, Lora S. Koenig, John Paden, Cameron Lewis, S. Prasad Gogineni, Carl Leuschen & Joseph R. McConnell
Nature Geoscience 7, 95-98 (2014) doi: 10.1038/ngeo2043
Radar and ice-core observations provide direct evidence of a perennial aquifer in the firn layer in southern Greenland that represents a potentially significant contribution to the Greenland mass budget. A regional climate model was used to estimate the aquifer area at about 70 000km2 and the depth to the top of the water table as 5-50m.
8. Palaeoclimate: Lags within the Younger Dryas
Ana Moreno
Nature Geoscience 7, 87-88 (2014) doi: 10.1038/ngeo2072
A slowing Atlantic overturning circulation during the last deglacial warming caused abrupt cooling in the Northern Hemisphere. Rach et al. used a well-dated, annually resolved sediment core from Lake Meerfelder Maar in western Germany and measured the hydrogen isotopes of aquatic and terrestrial lipid biomarkers. Hydrological change in Europe was found to lag behind the temperature drop by almost 200 years.
NATURE COMMUNICATIONS
9. Greenhouse conditions induce mineralogical changes and dolomite accumulation in coralline algae on tropical reefs
Guillermo Diaz-Pulido, Merinda C. Nash, Kenneth R. N. Anthony, Dorothea Bender, Bradley N. Opdyke, Catalina Reynes-Nivia & Ulrike Troitzsch
Nature Communications 5, Article number: 3310 doi: 10.1038/ncomms4310
Due to the presence of multiple carbonate minerals with different solubilities in seawater, the algal mineralogical responses to changes in carbonate chemistry are poorly understood. The researchers found an increase in dolomite concentration in living crustose coralline algae under greenhouse conditions.
10. Discovery of a novel methanogen prevalent in thawing permafrost
Rhiannon Mondav, Ben J. Woodcroft, Eun-Hae Kim, Carmody K. McCalley, Suzanne B. Hodgkins, Patrick M. Crill, Jeffrey Chanton, Gregory B. Hurst, Nathan C. VerBerkmoes, Scott R. Saleska, Philip Hugenholtz, Virginia I. Rich & Gene W. Tyson
Nature Communications 5, Article number: 3212 doi: 10.1038/ncomms4212
Thawing permafrost promotes microbial degradation of cryo-sequestered and new carbon leading to the biogenic production of methane, creating a positive feedback to climate change. Microbial community composition along a permafrost thaw gradient in northern Sweden was looked at and a single archaeal phylotype Methanoflorens stordalenmirensis dominated partially thawed sites. Metagenomic sequencing suggests that this lineage is both prevalent and a major contributor to global methane production.
