Primary productivity in the Southern Ocean plays an important role in the drawdown of atmospheric CO2, but phytoplankton growth is limited by iron. Here the authors show that iron from hydrothermal vents fuels massive phytoplankton blooms in the Southern Ocean that have recurred in the same location for decades.
Earth science encompasses geological, hydrological, atmospheric and meteorological research that paves the way towards better understanding of the planet on which we live. From deep in the Earth’s interior to the highest reaches of the atmosphere, the work highlighted here shows significant research advances in the physical, chemical and biological processes that shape the Earth system’s past, present and future.
The authors here present a multi-lake paleoseismological approach to evaluate the role of earthquakes in causing a spatio-temporal cluster of large, prehistoric rockslides between 3000 and 4200 years ago in the Eastern European Alps and for which the triggering mechanisms are still debated.
Generally it is thought that ash aggregation leads to reduced atmospheric travel distances. Here, the authors show that the rafting effect can increase dispersal range by up to 3.7 times for particles between 300–500 μm, compared to sedimentation of individual clasts.
The fastest sea-ice decline has been observed in the western Arctic, but the underlying mechanisms are still unclear. Here, the authors show that the Pacific North American pattern plays an important role in western Arctic sea-ice variability.
What controlled changes of glaciers in the European Alps at the time of their largest extent, about 25,000 years ago, is not well known. Here, the authors use cryogenic carbonates in caves to show that heavy snowfall during autumn and early winter was the main source of glacier growth.
It is widely hypothesised that primeval life utilized small organic molecules as sources of carbon and energy, however, the presence of such primordial ingredients in early Earth habitats has not yet been demonstrated. Here the authors report the existence of indigenous organic molecules and gases in primary fluid inclusions in c. 3.5- billion-year-old rocks from Western Australia.
The Arctic Ocean is influenced by carbon and nutrients from rivers and erosion, but how this affects phytoplankton productivity is not understood. Here, the authors use a spatio-temporally resolved biogeochemical model to estimate that the input of carbon and nutrients fuels 28–51% of annual Arctic Ocean productivity.
Floods are an important natural disaster on the Indonesian island of Sumatra, but their driving mechanisms are not well understood. Here, the authors utilize data from twitter messages and local newspaper reports to show that convectively coupled Kelvin waves play a key role in promoting floods on Sumatra.
Some palaeotemperature proxies suffer from inaccuracies related to kinetic fractionations occurring during carbonate mineral growth. Here, the authors show that dual clumped isotope thermometry can identify the origin of these kinetic biases and allows for the reconstruction of accurate environmental temperatures.
The unprecedented cost of the 2018 eruption in Hawai’i reflects an intersection of disparate physical and social phenomena: widely spaced, highly destructive eruptions, and atypically high population growth. These were linked and the former indirectly drove the latter with unavoidable consequences.
This review dives deep into how earthquakes affect volcanoes, specifically into the relation between tectonic seismic activity and subsequent eruptions. Activity may increase in any volcanic setting in the 2–5 years following an earthquake, and especially at volcanic centres featuring vigorous hydrothermal activity.
The fate of subducted CO2 remains debated, with estimates mainly from numerical predictions varying from wholesale decarbonation of the shallow subducting slab to massive deep subduction of CO2. Here, the authors present field-based data and show that ~40% to ~65% of the CO2 in subducting crust is released via metamorphic decarbonation reactions at forearc depths.
Marine heatwaves are likely to intensify in a warmer world, but prediction of these events is hampered by course-scale modeling. Here the authors develop a fine scale, global model which shows that marine heatwaves will amplify with greater spatial variability, particularly at western boundary regions.
Phosphorus is an essential nutrient critical for agriculture, but because it is non-renewable its future availability is threatened. Here the authors show that across the globe most nations have net losses of phosphorus, with soil erosion as the major route of loss in Europe, Africa and South America.
International agreements have been implemented to reduce emissions of hydrofluorocarbons (HFCs) to reduce their radiative forcing. Even though reported HFC-23 emissions are at a historical low, observations indicate that emissions have actually increased over recent years to higher levels than previously.
Ocean oxygen minimum zones (OMZs) are known to emit the powerful greenhouse gas N2O, but global emission dynamics are not constrained. Here the authors use air trajectory analyses and find that air masses pick up N2O as they pass over OMZs, and that overall concentrations are elevated during La Niña events.
The mid-Holocene has seen a number of climate shifts, which have been associated with societal changes. Here, the authors investigate in a centuries long megadrought in Southeast Asia during the mid-Holocene, possibly caused by the end of the Green Sahara period.
Unconventional oil and gas production has increased drastically in the US, but its environmental impacts are not well known. Here, the authors show that these wells can be associated with elevated levels of airborne particle radioactivity in downwind locations.
Cooling of the iron core in the early Earth may have been too slow to allow for the generation of a magnetic field. Based on quantum mechanical and geodynamical modelling approaches, the authors find that the electrical conductivity of silicate liquid at high pressure and temperature conditions could have been sufficient to generate a silicate dynamo and a magnetic field in the early Earth.
Global resources of heavy Rare Earth Elements (REE) are dominantly sourced from Chinese regolith-hosted ion-adsorption deposits, yet the adsorption mechanisms remain unclear. Here, the authors find that heavy REE are adsorbed as easily leachable 8-coordinated outer-sphere hydrated complexes, dominantly onto kaolinite, in clays from both China and Madagascar.
The Greenland Ice Sheet is the largest land ice contributor to sea level rise and understanding the long-term glacier response to external forcing is key to improved projections. Here the authors show Greenland’s three largest outlet glaciers will likely exceed current worst-case scenario
Human activities have accelerated soil erosion and landscape change in many areas. Here the authors show how rates of erosion, sediment transfer and alluvial sedimentation have increased by an order of magnitude across North America since European colonization, far exceeding the rates expected of natural processes.
Glaciers in the European Alps are strongly affected by global warming, yet there is no methodologically consistent alpine-wide analysis on glacier changes. Here the authors show significant glacier retreat and an ice mass loss of 1.3 ± 0.2 Gt a−1, derived from contemporaneous measurements of glacier areas and elevations.
Sulfur is one of the key volatiles in Earth’s chemical cycles; however, sulfur speciation, isotopic composition, and flux during the subduction cycle remain unclear. Here, the authors provide direct constraints on subduction zone sulfur recycling from high-pressure rocks and explore implications for arc magmatism.
The transition from wide continental rift to continental break-up remains enigmatic. Here, the authors show that northern margin of the South China Sea records the transition between wide continental rift to a highly extended continental margin, with strikingly similar structures and metamorphic core complexes to those described from the North American Cordillera and the Aegean.
Earth’s drylands are expected to expand due to climate change, but how this will affect vegetation remains unclear. Here the authors use models to show that despite expansion, primary productivity in drylands is likely to increase through the 21st Century.
Plastic pollution has infiltrated every ecosystem, but few studies have quantified the biogeochemical or ecological effects of plastic. Here the authors show that microplastics in ocean sediment can significantly alter microbial community structure and nitrogen cycling.
The COVID-19 pandemic has stopped many human activities, which has had significant impact on emissions of greenhouse gases. Here, the authors present daily estimates of country-level CO2 emissions for different economic sectors and show that there has been a 8.8% decrease in global CO2 emissions in the first half of 2020.
Several dams and reservoirs exist along the Nile, most notably the HAD (Egypt) and GERD (Ethiopia) dams. Due to the lack of strategies, the authors here explore potential risks and solutions how to use both dams simultaneously.