- Michael Behrenfeld: Marine biogeochemistry: Phytoplankton in a witch's brew 2016-01-25+
Natural seafloor hydrocarbon seeps are responsible for roughly half of the oil released into the ocean. As these oils and gases rise to the surface, they transport nutrients upwards, benefiting phytoplankton in the upper sunlit layer.
- James N. Galloway: Sustainability: Your feet's too big 2016-01-25+
Humanity's nitrogen pollution footprint has increased by a factor of six since the 1930s. A global analysis reveals that a quarter of this nitrogen pollution is associated with the production of internationally traded products.
- Ian J. Fairchild: Ocean chemistry: Neoproterozoic glass-bleeding 2016-01-18+
Volcanic eruptions at ocean ridges produce large volumes of glass that is rapidly leached by seawater. Geochemical calculations suggest that this process helps to explain the deposition of carbonates at the end of extreme ice ages.
- Jeffra K. Schaefer: Biogeochemistry: Better living through mercury 2016-01-18+
Mercury is a toxic element with no known biological function. Laboratory studies demonstrate that mercury can be beneficial to microbial growth by acting as an electron acceptor during photosynthesis.
- Heather M. Stoll: Palaeoclimate: Aptian mystery solved 2016-01-04+
The volcanic eruption that created the Ontong Java Plateau released large quantities of carbon dioxide. A reconstruction of CO2 concentrations suggests that the eruption promoted climate change and the expansion of ocean anoxia.
- Ying Fan: Groundwater: How much and how old? 2015-11-16+
A global picture of the age structure and flow path of groundwater is lacking. Tritium concentrations and numerical modelling shed light on both the most recently replenished and the longest stored groundwater within Earth's continents.
- Martin Wik: Climate-sensitive northern lakes and ponds are critical components of methane release 2016-01-04+
Lakes are sources of the greenhouse gas methane. A synthesis of measurements of methane emissions reveals that lakes and ponds above 50 °N emit 16.5 Tg methane annually, and emissions may increase by 20 to 50% with longer ice-free seasons.
- W. T. Ball: High solar cycle spectral variations inconsistent with stratospheric ozone observations 2016-01-25+
Variability in solar UV radiation is uncertain, but it affects Earth’s climate. Simulations of the ozone response to various data sets of spectral solar irradiance show that high-amplitude solar variability is inconsistent with ozone observations.
- N. A. D’souza: Elevated surface chlorophyll associated with natural oil seeps in the Gulf of Mexico 2016-01-25+
Natural hydrocarbon seeps account for up to 47% of the oil released into the oceans. In situ and remote measurements of chlorophyll concentrations suggest that natural hydrocarbons enhance productivity in surface waters in the Gulf of Mexico.
- Henk Kooi: Groundwater flow as a cooling agent of the continental lithosphere 2016-01-25+
Groundwater flow redistributes heat in the Earth’s crust. Numerical simulations of groundwater flow show net cooling of groundwater basins, as well as cooling of the underlying lithosphere in areas where groundwater flows over large distances.
- Azusa Oita: Substantial nitrogen pollution embedded in international trade 2016-01-25+
Anthropogenic emissions of reactive nitrogen have had severe environmental impacts. An analysis of reactive nitrogen emissions from the production, consumption and transport of commodities attributes roughly a quarter to international trade.
- D. S. Grégoire: A physiological role for HgII during phototrophic growth 2016-01-18+
Bacteria have been shown to be involved in the reduction of HgII to elemental mercury. Laboratory experiments with HgII and different carbon sources reveal that purple bacteria can use HgII as an electron acceptor, promoting bacterial growth.
- Scott Jasechko: Substantial proportion of global streamflow less than three months old 2016-01-18+
Streamflow is a mixture of precipitation of various ages. Oxygen isotope data suggests that a third of global river discharge is sourced from rainfall within the past few months, which accounts for less than 0.1% of global groundwater.
- Hyunwoo Lee: Massive and prolonged deep carbon emissions associated with continental rifting 2016-01-18+
Transfer of CO2 from Earth’s interior to the atmosphere happens largely by volcanic degassing. Measurements of CO2 emissions from faults in the East African Rift system imply that tectonic degassing is also important for deep carbon release.
- Luis P. A. M. Duprat: Enhanced Southern Ocean marine productivity due to fertilization by giant icebergs 2016-01-11+
Nutrient input from icebergs can fertilize productivity in the ocean. Ten years of satellite measurements reveal that giant icebergs could be responsible for up to 20% of carbon export to depth in the Southern Ocean.
- B. D. A. Naafs: Gradual and sustained carbon dioxide release during Aptian Oceanic Anoxic Event 1a 2016-01-04+
A period of ocean anoxia about 120 million years ago coincided with high temperatures. A reconstruction of CO2 concentrations shows that volcanic outgassing from the Ontong Java Plateau caused CO2 levels to double during the anoxic event.
- Gaby Rädel: Amplification of El Niño by cloud longwave coupling to atmospheric circulation 2016-01-04+
The El Niño/Southern Oscillation (ENSO) affects weather patterns worldwide. Numerical experiments with an Earth system model suggest that cloud feedbacks act to amplify ENSO variability by a factor of two or more.
- Jean Liu: Sea-level constraints on the amplitude and source distribution of Meltwater Pulse 1A 2015-12-21+
Sea level rose rapidly during Meltwater Pulse 1A, about 14,500 years ago. A reassessment of sea-level rise and isostatic adjustment suggests sea level rose roughly 8 to 15 m in total, with 0 to 10 m derived from the Antarctic ice sheets.
- J. C. Villegas-Lanza: A mixed seismic–aseismic stress release episode in the Andean subduction zone 2015-12-21+
Subduction zone earthquakes can be followed by aseismic slip. Analysis of fault slip in northern Peru reveals transient aseismic slip that lasted for seven months and released more than 1,000% of the energy expelled by the quake that preceded it.
- Dave Craw: Rapid biological speciation driven by tectonic evolution in New Zealand 2015-12-14+
Plate tectonic motions can influence biological systems. Numerical modelling of the topographic evolution of New Zealand, combined with fish phylogenetic analyses suggest mountain growth directly influenced biological diversification.
- C. Soued: Nitrous oxide sinks and emissions in boreal aquatic networks in Québec 2015-12-14+
Aquatic ecosystems are important sources of the greenhouse gas nitrous oxide. Measurements of nitrous oxide concentrations from 321 rivers, lakes and ponds in Canada reveal that some boreal aquatic systems can act as net nitrous oxide sinks.
- T. M. Gernon: Snowball Earth ocean chemistry driven by extensive ridge volcanism during Rodinia breakup 2016-01-18+
The Cryogenian Snowball Earth glaciations were followed by the deposition of massive cap carbonates. Geochemical modelling suggests that shallow-ridge volcanism supplied much of the alkalinity and cations that fuelled this deposition.
- J. R. Elliott: Himalayan megathrust geometry and relation to topography revealed by the Gorkha earthquake 2016-01-11+
How Himalayan topography is built is unclear. Analysis of surface displacement during the 2015 Gorkha earthquake suggests that large earthquakes may lower the high Himalayan mountains, and topography may grow during the interseismic phase.
- Katie A. Smart: Early Archaean tectonics and mantle redox recorded in Witwatersrand diamonds 2016-01-11+
The time at which plate tectonics were initiated on Earth is unclear. Geochemical analysis of diamonds suggests that recycled oxidized material could have been introduced to the mantle via subduction zones more than 3 billion years ago.
- Christina M. Patricola: Degree of simulated suppression of Atlantic tropical cyclones modulated by flavour of El Niño 2015-12-21+
El Niño events tend to suppress Atlantic hurricane activity. Simulations with high-resolution climate models show that the efficiency of this suppression mechanism varies with the flavour of the El Niño event.
- J. Emile-Geay: Links between tropical Pacific seasonal, interannual and orbital variability during the Holocene 2015-12-14+
The frequency and amplitude of the El Niño/Southern Oscillation varied during the Holocene. A comparison of proxy records and model simulations suggests that any link between orbital forcing and this variability is either complex or non-existent.
- Tom Gleeson: The global volume and distribution of modern groundwater 2015-11-16+
Groundwater recharged less than 50 years ago is vulnerable to contamination and land-use changes. Data and simulations suggest that up to 6% of continental groundwater is modern—forming the largest component of the active hydrologic cycle.
