Nature Geoscience contents: March 2014 Volume 7 Number 3 pp157-244

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TABLE OF CONTENTS March 2014 Volume 7, Issue 3 Editorial Commentaries Books and Arts Research Highlights News and Views Review Letters Articles Subscribe   Facebook   RSS   Recommend to library   Twitter   Editorial Top Hiatus in context   p157 doi:10.1038/ngeo2116 The recent slow-down in the rate of warming, averaged over the surface of the entire planet, has incited much discussion. As climate scientists are tracking down the causes, we must not forget that average surface temperatures are only one indicator of climate change. Commentaries Top Reconciling warming trends   pp158 - 160 Gavin A. Schmidt, Drew T. Shindell and Kostas Tsigaridis doi:10.1038/ngeo2105 Climate models projected stronger warming over the past 15 years than has been seen in observations. Conspiring factors of errors in volcanic and solar inputs, representations of aerosols, and El Niño evolution, may explain most of the discrepancy. Bumpy path to a warmer world   pp160 - 161 Martin Visbeck doi:10.1038/ngeo2104 Decadal climate variability has long received limited attention. With the slow-down in surface warming since the late 1990s, the decadal scale has rightly become a focus of attention: for assessing climate change and its impacts, it is of critical importance. Books and Arts Top Exhibition: Lunar reflections and astronaut geese   p162 doi:10.1038/ngeo2103 Research Highlights Top Geochemistry: Helium escape | Planetary science: Ring around Saturn | Climate change: Europe heats up | Deep Earth: Cool core boundary News and Views Top Palaeoclimate: The sea ice thickens   pp165 - 166 Catherine E. Stickley doi:10.1038/ngeo2080 Little is known about the presence of high-latitude sea ice before 2.6 million years ago. A reanalysis of marine sediments from the Arctic Ocean indicates an intermittent presence of perennial sea ice as early as 44 million years ago. See also: Letter by Darby Climate change: Impacts in the third dimension   pp166 - 167 Michael Dettinger doi:10.1038/ngeo2096 Despite reports of no trends in snow- and rainfall, rivers in the northwest USA have run lower and lower in recent decades. A closer look at high- and low-altitude precipitation suggests that observational networks have missed a decline in mountain rain and snow that can explain the discrepancy. Volcanology: Look up for magma insights   pp168 - 169 Paul Segall and Kyle Anderson doi:10.1038/ngeo2064 Volcanic plumes can be hazardous to aircraft. A correlation between plume height and ground deformation during an eruption of Grímsvötn Volcano, Iceland, allows us to peer into the properties of the magma chamber and may improve eruption forecasts. See also: Letter by Hreinsdóttir et al. Early Earth: Closing the gap   pp169 - 170 Samuel Bowring doi:10.1038/ngeo2100 The age of the oldest Jack Hills zircons — Earth's oldest minerals — is contentious. Atomic-scale mapping of the distribution of radiogenic isotopes within a Jack Hills zircon confirms that the oldest known continental crust formed just after the Earth–Moon system. See also: Letter by Valley et al. Mass extinctions: Ecological diversity maintained   pp171 - 172 Martin Aberhan doi:10.1038/ngeo2085 The end-Permian extinction decimated marine life on an unprecedented scale. However, an analysis of the lifestyles of the surviving genera shows that very little functional diversity was lost at the sea floor. See also: Article by Foster & Twitchett Geoscience JOBS of the week Faculty Positions Department of Earth, Atmospheric and Planetary Sciences MIT More Science jobs from Geoscience EVENT Annual International Conference on Earth and Environmental Sciences 14.07.14 Athens, Greece More science events from Review Top Terrestrial carbon cycle affected by non-uniform climate warming   pp173 - 180 Jianyang Xia, Jiquan Chen, Shilong Piao, Philippe Ciais, Yiqi Luo et al. doi:10.1038/ngeo2093 Feedbacks between the terrestrial carbon cycle and climate change could affect many ecosystem functions and services. A synthesis of global air temperature data reveals non-uniform rates of climate warming on diurnal and seasonal timescales, and heterogeneous impacts on ecosystem carbon cycling. Letters Top Arctic amplification dominated by temperature feedbacks in contemporary climate models   pp181 - 184 Felix Pithan and Thorsten Mauritsen doi:10.1038/ngeo2071 Changes in climate are amplified in the Arctic region. An analysis of the CMIP5 state-of-the-art climate models reveals that temperature feedbacks are the dominant factor in this amplification, whereas the change in reflectivity of the Earth's surface as sea ice and snow melt makes only a secondary contribution. Volcanic contribution to decadal changes in tropospheric temperature   pp185 - 189 Benjamin D. Santer, Céline Bonfils, Jeffrey F. Painter, Mark D. Zelinka, Carl Mears et al. doi:10.1038/ngeo2098 Global mean surface and tropospheric temperatures have shown slower warming since 1998 than found in climate model simulations. A detailed analysis of observations and climate model simulations suggests that the observed influence of volcanic eruptions on tropospheric temperature has been significant, and that the discrepancy between climate simulations and observations is reduced by up to 15% when twenty-first century volcanic eruptions are accounted for in the models. Carbon isotope equilibration during sulphate-limited anaerobic oxidation of methane   pp190 - 194 Marcos Y. Yoshinaga, Thomas Holler, Tobias Goldhammer, Gunter Wegener, John W. Pohlman et al. doi:10.1038/ngeo2069 The flux of methane from the sea bed to the overlying water column is mitigated by the sulphate-dependent anaerobic oxidation of methane by marine microbes. Laboratory experiments point to the equilibration of stable carbon isotopes during the anaerobic oxidation of methane under sulphate-limited conditions. Humic substances as fully regenerable electron acceptors in recurrently anoxic environments   pp195 - 200 Laura Klüpfel, Annette Piepenbrock, Andreas Kappler and Michael Sander doi:10.1038/ngeo2084 Humic substances make up a significant fraction of the natural organic matter in terrestrial and aquatic environments. Laboratory experiments suggest that humic substances serve as fully regenerable electron acceptors in recurrently anoxic environments such as peatlands. Significant contribution of authigenic carbonate to marine carbon burial   pp201 - 204 Xiaole Sun and Alexandra V. Turchyn doi:10.1038/ngeo2070 Carbon is removed from the Earth's surface through the formation and burial of carbon-bearing rocks and minerals. An analysis of pore water profiles collected from marine sediments around the globe suggests that the precipitation of authigenic calcium carbonate accounts for around 10% of the carbonate that accumulates in marine sediments globally. Modern and glacial tropical snowlines controlled by sea surface temperature and atmospheric mixing   pp205 - 209 Aradhna K. Tripati, Sandeep Sahany, Dustin Pittman, Robert A. Eagle, J. David Neelin et al. doi:10.1038/ngeo2082 During the Last Glacial Maximum, tropical glacier snowlines were lower than expected, based on estimates of tropical sea surface temperatures. Sea surface temperature reconstructions suggest the Indo-Pacific warm pool was cooler than previously thought; these temperatures and convective mixing processes can explain snowline altitude in this region. Ephemeral formation of perennial sea ice in the Arctic Ocean during the middle Eocene   pp210 - 213 Dennis A. Darby doi:10.1038/ngeo2068 Arctic sea ice is a key component of the modern climate system. Marine sediment analyses suggest that perennial sea ice in the Arctic Ocean first formed—transiently—about 44 million years ago. See also: News and Views by Stickley Volcanic plume height correlated with magma-pressure change at Grímsvötn Volcano, Iceland   pp214 - 218 Sigrún Hreinsdóttir, Freysteinn Sigmundsson, Matthew J. Roberts, Halldór Björnsson, Ronni Grapenthin et al. doi:10.1038/ngeo2044 The 2011 eruption of a 20-km-high volcanic plume from Grímsvötn Volcano, Iceland, led to the closure of northern European airspace. Geodetic measurements from the volcano reveal a correlation between plume height, surface deformation and magma-chamber pressure, with a delay of an hour, implying that volcanic-plume behaviour can be predicted before eruption onset. See also: News and Views by Segall & Anderson Hadean age for a post-magma-ocean zircon confirmed by atom-probe tomography   pp219 - 223 John W. Valley, Aaron J. Cavosie, Takayuki Ushikubo, David A. Reinhard, Daniel F. Lawrence et al. doi:10.1038/ngeo2075 The oldest minerals on Earth are thought to have formed in the Hadean eon, but the reliability of the dates has been questioned. Atom-probe tomography of an ancient zircon confirms that the mineral formed about 4.4 billion years ago, implying that any mixing event of the silicate Earth occurred before that time. See also: News and Views by Bowring Stability of hydrous silicate at high pressures and water transport to the deep lower mantle   pp224 - 227 M. Nishi, T. Irifune, J. Tsuchiya, Y. Tange, Y. Nishihara et al. doi:10.1038/ngeo2074 Hydrous magnesium-rich silicates play an important role in transporting water into the deep mantle when oceanic plates subduct as slabs, but were thought to dissociate at pressures of 44 GPa. In situ X-ray measurements in conjunction with a multi-anvil apparatus show that hydrous phases of magnesium-rich silicate are stable under lower mantle conditions up to 50 GPa, and may transport water to deeper layers of the mantle. Articles Top Contribution of sea surface carbon pool to organic matter enrichment in sea spray aerosol   pp228 - 232 Patricia K. Quinn, Timothy S. Bates, Kristen S. Schulz, D. J. Coffman, A. A. Frossard et al. doi:10.1038/ngeo2092 Breaking waves on the ocean surface generate air bubbles that yield sea spray aerosols when released to the atmosphere. Measurements of sea spray aerosols in the North Atlantic Ocean and the coastal waters of California suggest that the surface water organic carbon reservoir is responsible for the organic carbon enrichment of freshly emitted sea spray aerosol. Functional diversity of marine ecosystems after the Late Permian mass extinction event   pp233 - 238 William J. Foster and Richard J. Twitchett doi:10.1038/ngeo2079 At least two-thirds of marine genera died out during the end-Permian mass extinction about 252 million years ago. An analysis of extinct and surviving taxa shows no substantial loss in global functional diversity, although there were significant losses in some settings such as tropical reefs. See also: News and Views by Aberhan Formation of the Grand Canyon 5 to 6 million years ago through integration of older palaeocanyons   pp239 - 244 Karl E. Karlstrom, John P. Lee, Shari A. Kelley, Ryan S. Crow, Laura J. Crossey et al. doi:10.1038/ngeo2065 The age of the Grand Canyon is fervently debated. Thermochronological reconstructions of canyon incision show that although parts of the canyon were carved more than 50 million years ago, two key segments formed less than 6 million years ago, implying that the canyon is a young feature. Top Natureevents is a fully searchable, multi-disciplinary database designed to maximise exposure for events organisers. The contents of the Natureevents Directory are now live. The digital version is available here. Find the latest scientific conferences, courses, meetings and symposia on natureevents.com. For event advertising opportunities across the Nature Publishing Group portfolio please contact natureevents@nature.com More Nature Events

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