Earth and environmental sciences

  • Article
    | Open Access

    Coral reef health is declining globally and is projected to lead to net loss of reef structure. This study shows that ecological change across the Caribbean has reduced reef growth rates to levels lower than those measured over the last ~8,000 years, threatening the ability of reefs to keep pace with future sea-level rise.

    • Chris T. Perry
    • , Gary N. Murphy
    •  & Peter J. Mumby
  • Article
    | Open Access

    Active seafloor spreading has been documented in some of the tectonically active basins of the Gulf of California. This work presents new geophysical and geochemical data as evidence that active seafloor spreading is also occurring in the northernmost Wagner and Consag basins of the Gulf.

    • Rosa Ma Prol-Ledesma
    • , Marco-Antonio Torres-Vera
    •  & Carlos Robinson
  • Article |

    Rivers receive more terrestrial carbon than they transport to the ocean, leaving carbon stored along the way. Here, with an estimate of carbon storage in the headwater rivers of the Rocky Mountains, the authors show that broad valley bottoms with old-growth forest store most of the above- and below-ground carbon.

    • Ellen Wohl
    • , Kathleen Dwire
    •  & Roberto Bazan
  • Article |

    Microbes appear to play an important role in carbon sequestration. Here, the composition of microbial residues in a California grassland with elevated carbon dioxide, warming and nitrogen deposition reveals that warming and nitrogen deposition can both alter the fraction of carbon derived from microbes in soils.

    • Chao Liang
    •  & Teri C. Balser
  • Article |

    Mineral cave deposits—speleothems—provide a record of past rainfall changes. This study presents a speleothem data-set from southwestern Oregon, revealing winter climate change over the past 13,000 years with abrupt transitions between warm-dry and cold-wet regimes influenced by solar forcing.

    • Vasile Ersek
    • , Peter U. Clark
    •  & R. Lawrence Edwards
  • Article |

    Changes in bubble foam structure influence magma strength. Here, Bakeret al. measure bubble size and wall thickness of basaltic foams and find that basaltic magmas are most likely to fail immediately upon vesiculation, but a permeability increase within a few seconds may reduce the risk of explosive eruptions.

    • Don R. Baker
    • , Francesco Brun
    •  & Mark Rivers
  • Article |

    Reconstructing short-term plate-motion changes through time provides important geodynamical information, but data noise is a problem at fine temporal resolution. This study presents a trans-dimensional hierarchical Bayesian framework that eliminates noise without loss of temporal resolution.

    • Giampiero Iaffaldano
    • , Thomas Bodin
    •  & Malcolm Sambridge
  • Article
    | Open Access

    Palaeoclimate proxies, such as shells, record past ocean changes. A radiocarbon study based on a shell chronology from the Icelandic shelf is used to track changes in ocean circulation and climate for the past 1,350 years, suggesting a declining influence of North Atlantic surface waters on the Icelandic shelf over the last millennium.

    • Alan D. Wanamaker Jr
    • , Paul G. Butler
    •  & Christopher A. Richardson
  • Article |

    Kimberlites are volatile-rich magmas that form diverging pipes containing pelletal lapilli - well rounded clasts that consist of an inner seed particle. Gernonet al. suggest that pelletal lapilli are formed when fluid volatile-rich melts intrude into earlier volcaniclastic infill close to the diatreme root zone.

    • T.M. Gernon
    • , R.J. Brown
    •  & T.K. Hincks
  • Article |

    Small-scale ocean dynamics can have wide reaching impacts on the larger-scale ocean circulation. Using temperature and velocity data, this study shows the presence of abyssal vortices in the Eastern Mediterranean basin, adding complexity to the structure and evolution of water masses in this region.

    • A. Rubino
    • , F. Falcini
    •  & A. Capone
  • Article |

    The damaging effects of loud noise on auditory function are well established, but the effects of low-level noise are not so well understood. Zhou and Merzenich chronically expose adult rats to structured low-level noise and find that it causes auditory cortex damage and sound discrimination impairment.

    • Xiaoming Zhou
    •  & Michael M. Merzenich
  • Article
    | Open Access

    The calving of the Mertz Glacier occurred in 2010 in East Antarctica, brought on by the re-positioning of a large iceberg. Using satellite data, this study shows a reduction in sea ice production following the calving, interpreted as a potential regime shift towards reduced sea ice production for the coming decades.

    • T. Tamura
    • , G.D. Williams
    •  & K.I. Ohshima
  • Article
    | Open Access

    Ocean circulation moves heat and gases between the ocean and atmosphere, impacting the carbon cycle at decadal timescales. Here, a radiocarbon coral record of ocean mixing from Bermuda suggests that the formation of mode water, and thus carbon uptake, have been more stable over the past 200 years than previously thought.

    • Nathalie F. Goodkin
    • , Ellen R. M. Druffel
    •  & Scott C. Doney
  • Article |

    A record of the daily light cycle in tropical regions is difficult to extract from biogenic marine carbonates such as shells. Here, the precise analysis of Sr/Ca ratios is shown in a cultivated giant clam shell, revealing variations that reflect the daily light cycle and the potential for future development of a proxy.

    • Yuji Sano
    • , Sayumi Kobayashi
    •  & Kenji Iwai
  • Article |

    Understanding the environmental controls of past wildfires is difficult due to the lack of records of weather or vegetation. This study shows, using cross-scale analysis, how power laws associated with fire-event time series can identify critical thresholds in landscape dynamics in a rapidly changing climate.

    • Donald McKenzie
    •  & Maureen C. Kennedy
  • Article |

    A detailed assessment of near-shore temperature changes is needed for improved forecasts of the consequences of coastal warming. Here, changes in coastal sea surface temperature are estimated, showing that although 71% of the world's coastlines are warming, the rates of change have varied spatially.

    • Fernando P. Lima
    •  & David S. Wethey
  • Article |

    Dolomite sedimentary rock has lateral metre-scale periodic variations in porosity and composition, which may provide information on formation and transformation. This study suggests that such variations are fossilized chemical waves emerging from stress-mediated mineral-water interaction during sediment burial diagenesis.

    • Yifeng Wang
    •  & David A. Budd
  • Article |

    The Younger Dryas cold period is thought to have occurred mainly due to the release of fresh water into the North Atlantic from the glacial Lake Agassiz. Here, sedimentary and geochemical data from the central Arctic Ocean support the hypothesis of a northward route drainage event from Lake Agassiz during the Younger Dryas.

    • Christelle Not
    •  & Claude Hillaire-Marcel
  • Article
    | Open Access

    The Mid-Cayman Spreading Centre is an ultraslow-spreading mid-ocean ridge in the Caribbean. This study reveals two hydrothermal vent fields on the ridge, including high-temperature vents on an off-axis oceanic core complex where, similar to Mid-Atlantic vents, an alvinocaridid shrimp is common at both vent fields.

    • Douglas P. Connelly
    • , Jonathan T. Copley
    •  & Sally Wilcox
  • Article |

    The habitat where early humans, hominins, lived provides information about the early part of human evolution. In this study, sedimentological and stable carbon and oxygen isotope data suggest homininArdipithecus ramiduslived in a river-margin forest in a wooded grassland landscape at Aramis, Ethiopia.

    • M. Royhan Gani
    •  & Nahid D. Gani
  • Article |

    Active shortening in the Central Andes shifted from the western to the eastern margin between 10-7 Myr ago, but the mechanism of formation is still unclear. Here, using critical wedge theory and local-scale fault friction calculations, this shift is proposed to have been controlled by changes in erosion patterns.

    • Kevin Norton
    •  & Fritz Schlunegger
  • Article |

    The night sky viewed from Earth is very bright at infrared wavelengths due to atmospheric emission, making land-based astronomy difficult in this spectral region. Here, a photonic filter is demonstrated to suppress this unwanted light, opening new paths to infrared astronomy with current and future telescopes.

    • J. Bland-Hawthorn
    • , S.C. Ellis
    •  & C. Trinh
  • Article |

    Osteoderms are bones embedded within the dermis and are common in reptiles. Here, two osteoderms from the sauropod dinosaur Rapetosaurus indicate that the largest osteoderm known has an internal cavity equivalent to half its total volume and may have functioned as a mineral reserve in harsh environmental conditions.

    • Kristina Curry Rogers
    • , Michael D'Emic
    •  & Amanda Cagan
  • Article |

    Peatlands are a sink for atmospheric carbon dioxide and make up a large soil carbon reservoir. Here, studies of the interaction between drainage and fire show that long-term carbon emissions will likely exceed rates of carbon uptake, reducing the northern peatland carbon sink.

    • M.R. Turetsky
    • , W.F. Donahue
    •  & B.W. Benscoter
  • Article |

    Many organisms are responding to a warming climate by shifts in spatial distribution. The poleward movement of silver hake,Merluccius bilinearis, over the last forty years is related to the position of the Gulf Stream and Atlantic meridional overturning circulation through changes in local bottom water temperature.

    • Janet A. Nye
    • , Terrence M. Joyce
    •  & Jason S. Link
  • Article |

    SiO2 glass and helium are important in various fields of science and engineering. Sato et al. show SiO2glass to be less compressible in helium under high pressure, which may be relevant for the interpretation of high-pressure experiments and in the design of new materials.

    • Tomoko Sato
    • , Nobumasa Funamori
    •  & Takehiko Yagi
  • Article |

    The internal textures of columnar-jointed lava flows and intrusions are poorly understood. Mattssonet al. propose a melt-migration model for Icelandic basalt driven by crystallization and volume decrease inside cooling columns, which explains the macroscopic features observed in columnar-jointed basalts.

    • Hannes B. Mattsson
    • , Luca Caricchi
    •  & Ann M. Hirt
  • Article |

    Assessments of future water availability in South America are uncertain based on multiple coupled general circulation models. Shiogamaet al.identify global-scale metrics for measuring the reliability of water resource assessments, and indicate a higher probability of drying in the Amazon basin.

    • Hideo Shiogama
    • , Seita Emori
    •  & Toru Nozawa
  • Article
    | Open Access

    The presence of earthworms is known to enhance the quality and moisture of soil in cool and wet climates. Evanset al. show that termites and ants can improve soil quality in warmer and drier climates—their presence results in elevated water infiltration and nitrogen content, leading to increased wheat yields.

    • Theodore A. Evans
    • , Tracy Z. Dawes
    •  & Nathan Lo
  • Article |

    Storm water runoff and wastewater effluent are discharged into oceans, but the full ecological effects of these discharges are unknown. Here, the authors examine the population structure of a marine organism, the bat star, and show that these discharges alter the genetic structure and larval dispersal of this species.

    • Jonathan B. Puritz
    •  & Robert J. Toonen
  • Article |

    Ocean acidification due to increasing carbon dioxide levels can affect the growth and viability of corals. In this study, the authors measured extension, calcification and density in Florida corals collected in 1996, and show that recent climate change did not cause a decline in their extension or calcification.

    • Kevin P. Helmle
    • , Richard E. Dodge
    •  & C. Mark Eakin
  • Article
    | Open Access

    Organisms are expected to adapt to climate change because of selection pressures. Here, the authors demonstrate that brown morphs of Finnish owls are selected against in winters with plentiful snow, and concordantly, increasing winter temperatures and lower snow fall results in the selection of the brown morph.

    • Patrik Karell
    • , Kari Ahola
    •  & Jon E. Brommer
  • Article
    | Open Access

    The infectious prion diseases affect numerous hoofed animal species, and it has been suggested that the properties of the local soil affect transmission of these diseases. Here, the authors studied two North American locations and demonstrate that soil clay content can influence the infection rate in deer.

    • W. David Walter
    • , Daniel P. Walsh
    •  & Michael W. Miller
  • Article |

    Clathrates are minerals with cage-like structural voids that can be filled by guest species; three types are plausible but only one has been observed in nature. Mommaet al. have discovered the remaining two types in Japanese marine sediments, and determined their structural similarity to natural gas hydrates.

    • Koichi Momma
    • , Takuji Ikeda
    •  & Yasuhiro Kudoh
  • Article
    | Open Access

    Predicting ecological impacts of climate change is complicated, because key biological parameters are unknown for future conditions. Using a mechanistic energy budget model to relate sea ice to polar bear reproduction, Molnáret al.predict decreases in litter size with anticipated changes in sea ice.

    • Péter K. Molnár
    • , Andrew E. Derocher
    •  & Mark A. Lewis
  • Article
    | Open Access

    The origin of the Atlantic Multidecadal Oscillation, a semi-periodic variability of sea-surface temperature, is unknown. Knudsenet al.show that 55- to 70-year climate oscillations existed throughout the last 8,000 years, suggesting that the Atlantic Multidecadal Oscillation is a permanent feature of the Holocene climate induced by internal ocean variability.

    • Mads Faurschou Knudsen
    • , Marit-Solveig Seidenkrantz
    •  & Antoon Kuijpers
  • Article
    | Open Access

    Microorganisms are abundant in many environments and understanding their dispersal between ecosystems is important for ecology and conservation. These authors demonstrate that cyanobacterial populations are specific to hot or cold deserts and that gene flow between different populations does not occur.

    • Justin Bahl
    • , Maggie C. Y. Lau
    •  & Stephen B. Pointing
  • Article |

    Antarctic bottom water is important for the global climate system, but its main source in East Antarctica was altered recently because of calving of the Mertz Glacier Tongue. The authors model this event and find large changes in dense water exports from the region.

    • Kazuya Kusahara
    • , Hiroyasu Hasumi
    •  & Guy D. Williams
  • Article |

    Continental export of silicon to the coast is linked to ocean carbon sinks, but terrestrial silicon fluxes have not been quantified. Here, human deforestation and cultivation of the landscape are shown to be the most important factors in silicon mobilization in temperate European watersheds.

    • Eric Struyf
    • , Adriaan Smis
    •  & Patrick Meire
  • Article
    | Open Access

    The Arctic Mid-Ocean Ridge spreads extremely slowly and hydrothermal vent fields have not been reported in its vicinity. Pedersenet al. describe a black smoker vent field with large hydrothermal deposits and novel fauna distinct from those found in similar environments in the Atlantic.

    • Rolf B. Pedersen
    • , Hans Tore Rapp
    •  & Steffen L. Jorgensen