Volume 11 Issue 4, April 2018

A comprehensive assessment of grounding-line migration rates around Antarctica, covering a third of the coast, suggests retreat in considerable portions of the continent, beyond the rates expected from adjustment following the Last Glacial Maximum.

The annual quantity of metal being used by humans has been on the rise. A new analysis of 43 major economies reveals the extent to which year-to-year fluctuations in metal footprints have been in lockstep with countries’ economic growth and changes in investment spending.

Substantial amounts of denitrification and other anaerobic metabolisms can occur in anoxic microenvironments within marine snow particles, according to model simulations. This microbial activity may have a global impact on nitrogen cycling.

Multi-disciplinary analyses of Earth’s most destructive volcanic systems show that continuous monitoring and an understanding of each volcano’s quirks, rather than a single unified model, are key to generating accurate hazard assessments.

A warm and semi-arid climate may be most consistent with geological evidence for flowing water on the surface of early Mars, despite the challenges of warming Mars under a faint young Sun.

Observations of the radiative forcing from methane at the Earth’s surface are influenced by absorption effects from water vapour, according to spectroscopic measurements and line-by-line calculations.

Terrestrial vegetation contributes to the seasonal variation of atmospheric mercury concentrations, according to analyses of atmospheric trace gas dynamics and satellite data. The data show that the photosynthetic activity of vegetation correlates with atmospheric mercury.

Winter floods flushed out 70% of the microplastic contamination from riverbed sediments in northwest England, according to analyses of sediment samples from 40 rural and urban sites.

Grounding lines in parts of West Antarctica, East Antarctica and the Antarctic Peninsula retreated faster than typical post-glacial pace, according to satellite observations and ice geometry measurements.

Particle microenvironments can sustain anaerobic metabolisms such as denitrification in hypoxic ocean areas, according to biogeochemical modelling. Rates of water column denitrification may be up to double previous estimates.

A country’s metal footprint increases by 2% for every 1% increase in gross capital formation, according to a metal footprint quantification and panel analysis of 43 economies during 1995–2013.

The shape of mid-ocean ridges is influenced by lithospheric mechanical strength, according to laboratory simulations of diverging plates. The results imply that large tectonic plates probably could not have formed on a younger, hotter Earth.

The Yellowstone hotspot could be fed by a thin, thermal mantle plume that extends from the core–mantle boundary to the surface position of the hotspot, according to analyses of seismic data.

The recurrence time of megathrust earthquakes in Chile may be controlled by frictional contrasts at depth, according to analyses of stress build-up and release related to the December 2016 southern Chile earthquake.