Volume 12 Issue 2, February 2019

Differences between earthquake sequences in the crust and adjacent uppermost mantle at oceanic transform faults are revealed by a seafloor seismic experiment at the Blanco Transform Fault.

Transition from a weak and erratic geomagnetic field to a more stable one around 560 million years ago, inferred from palaeomagnetic measurements, suggests that the inner core may have solidified around that time, much later than thought.

Atmospheric levels of chloroform, an ozone-depleting substance not part of the Montreal Protocol, have risen. The increase may be attributable to industrial emissions in Eastern China.

Cumulative wildfires or prescribed burning produce different outcomes for the vegetation, suggest two long-term analyses of fire-affected ecosystems. Climate change and land management practices are altering how ecosystems function.

Atmospheric levels of chloroform increased after 2010, as a result of emissions in eastern China, according to analyses of measurements and inverse modelling.

Any influence of the 11-year solar cycle on the North Atlantic Oscillation is insignificant, and could have been a chance occurrence, suggest analyses of the instrumental record and of chemistry–climate model simulations.

Explosive volcanic eruptions in the extratropics have cooled the climate in their hemisphere more than tropical eruptions, suggests an analysis of reconstructions since ad 750 and simulations with an atmosphere–aerosol model.

Prescribed burning has far less impacts on peat growth and carbon sequestration than previously thought, according to a long-term experiment in fire-managed peat moorlands in England. Managed burning may be a viable strategy to make peatlands more resilient to devastating wildfire.

Fires and logging alter soil composition and result in a significant reduction of soil nutrients that lasts for decades after the disturbance, suggests an analysis of soil samples across a multi-century sequence in mountain ash forests.

Microbial degradation is a key process for removing aromatic hydrocarbons from the oceans, according to measurements in plankton and seawater with 64 types of polycyclic aromatic hydrocarbons and their microbial degradation genes in four ocean basins.

A large reservoir of organic carbon persists in oxic pelagic sediments for millions of years as demonstrated by samples from the North Atlantic and South Pacific. This predominantly proteinaceous carbon persists due to physical protection and adsorption to mineral surfaces.

The sensitivity of the Antarctic ice sheet to obliquity increases when ice-sheet margins are exposed to the ocean, suggests an analysis of sediment core oxygen isotope records.

Earthquakes in the crust and mantle at transform faults are distinct yet coupled, with seismic swarms in the mantle apparently preceding large earthquakes, according to ocean-bottom seismic monitoring of the Blanco Transform Fault.

A late onset of inner-core growth is inferred from ultra-low palaeomagnetic field strengths about 565 million years ago, as measured in magnetic inclusions in Ediacaran crystals.