Nature Geoscience (NAT GEOSCI )

Publisher: Nature Publishing Group

Description

Impact factor 11.67

  • Hide impact factor history
     
    Impact factor
  • 5-year impact
    12.91
  • Cited half-life
    2.90
  • Immediacy index
    2.45
  • Eigenfactor
    0.08
  • Article influence
    7.95
  • Other titles
    Nature geoscience
  • ISSN
    1752-0894
  • OCLC
    187319519
  • Material type
    Document, Periodical, Internet resource
  • Document type
    Internet Resource, Computer File, Journal / Magazine / Newspaper

Publisher details

Nature Publishing Group

  • Pre-print
    • Author can archive a pre-print version
  • Post-print
    • Author cannot archive a post-print version
  • Restrictions
    • 6 months embargo
  • Conditions
    • Authors retain copyright
    • Published source must be acknowledged and DOI cited
    • Must link to publisher version
    • Publisher's version/PDF cannot be used
    • On author's personal website and institutional repository
    • If funding agency rules apply, authors may post authors version to their relevant funding body's archive, 6 months after publication
  • Classification
    ​ yellow

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: During the last and penultimate glacial maxima, atmospheric CO2 concentrations were lower than present, possibly in part because of increased storage of respired carbon in the deep oceans1.The amount of respired carbon present in awatermass can be calculated from its oxygen content through apparent oxygen utilization; the oxygen content can in turn be calculated from the carbon isotope gradient within the sediment column2. Here we analyse the shells of benthic foraminifera occurring at the sediment surface and the oxic/anoxic interface on the Portuguese Margin to reconstruct the carbon isotope gradient and hence bottom-water oxygenation over the past 150,000 years. We find that bottom-water oxygen concentrations were 45 and 65�mol kg􀀀1 lower than present during the last and penultimate glacial maxima, respectively.We calculate that concentrations of remineralized organic carbon were at least twice as high as today during the glacial maxima. We attribute these changes to decreased ventilation linked to a reorganization of ocean circulation3 and a strengthened global biological pump4. If the respired carbon pool was of a similar size throughout the entire glacial deep Atlantic basin, then this sink could account for 15 and 20 per cent of the glacial PCO2 drawdown during the last and penultimate glacial maxima.
    Nature Geoscience 12/2014; 8.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Groundwater chemistry has been observed to change before earthquakes and is proposed as a precursor signal. Such changes include variations in radon count rates1,2, concentrations of dissolved elements3–5 and stable isotope ratios4,5. Changes in seismicwave velocities6,water levels in boreholes7, micro-seismicity8 and shear wave splitting9 are also thought to precede earthquakes. Precursor activity has been attributed to expansion of rock volume7,10,11. However, most studies of precursory phenomena lack su cient data to rule out other explanations unrelated to earthquakes12. For example, reproducibility of a precursor signal has seldom been shown and few precursors have been evaluated statistically. Here we analyze the stable isotope ratios and dissolved element concentrations of groundwater taken from a borehole in northern Iceland between 2008 and 2013. We find that the chemistry of the groundwater changed four to six months before two greater than magnitude 5 earthquakes that occurred in October 2012 and April 2013. Statistical analyses indicate that the changes in groundwater chemistry were associated with the earthquakes. We suggest that the changes were caused by crustal dilation associated with stress build-up before each earthquake, which caused di�erent groundwater components to mix. Although the changes we detect are specific for the site in Iceland, we infer that similar processes may be active elsewhere, and that groundwater chemistry is a promising target for future studies on the predictability of earthquakes.
    Nature Geoscience 09/2014;
  • Nature Geoscience 08/2014; 7(9):621-623.
  • [Show abstract] [Hide abstract]
    ABSTRACT: River deltas support a disproportionate percentage of the world’s population and some are drowning as sea level rises. Resilient deltas theoretically balance relative sea-level rise with vertical growth from surface sedimentation.Vegetation generally enhances inorganic sedimentation and resiliency in some settings, such as tidal saltwater marshes, but the effect of vegetation on freshwater marshes in river deltas is less clear. Here we use a hydrodynamic numerical model to simulate deposition in a river delta with varying vegetation characteristics and water discharge and show that vegetation does not always enhance sedimentation on a freshwater marsh. For a given flood, we find that intermediate vegetation height and density are optimal for enhancing both sand and mud deposition, whereas tall or dense vegetation causes sand to remain in the river channel, reducing marsh sedimentation. A multivariate regression analysis of remote-sensing data from Wax Lake Delta, Louisiana, USA shows that the delta exhibits a hydrodynamic response to vegetation in agreement with model predictions. Because most sediment is delivered to freshwater deltaic marshes by infrequent storm and flood events, we further suggest that the timing of such events relative to seasonal vegetation growth determines the integrated effect of vegetation on delta resiliency.
    Nature Geoscience 08/2014;
  • Nature Geoscience 08/2014; 7(9):638-642.
  • Nature Geoscience 08/2014; 7(9):651-656.
  • Nature Geoscience 08/2014; 7(8):550.
  • Nature Geoscience 07/2014; 7(8):553-553.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Oceanic lavas are thought to be derived from di�erent sources within the Earth’s mantle, each with a distinct composition1–4. Large-scale plate motions provide the primary mechanism for mixing these sources, yet the geochemical signature of lavas erupted at di�erent mid-ocean ridges can still vary significantly5,6. Geochemical variability is low where plate spreading rates are high, consistent with plate-scale mixing5,6. However, slow-spreading centres, such as the Southwest Indian Ridge in the Indian Ocean, are also geochemically homogeneous, which is inconsistent with plate-scale mixing6,7. Here we use numerical simulations of mantle flowto study mantle mixing at mid-ocean ridges, under conditions with variable plate length and spreading rate. Our simulations reveal that small-scale convection in the mantle contributes significantly to mantle mixing at slow spreading rates; faster plate velocities and smaller plates inhibit small-scale convection. We conclude that whereas fast-spreading ridge lavas are well mixed by plate-scale flow, slow-spreading ridge lavas are mixed by small-scale convection.
    Nature Geoscience 07/2014; 7(8).
  • Nature Geoscience 07/2014; 7(8):583-587.