Volume 12 Issue 5, May 2019

Flotation of aerosols as a film on the hydrocarbon lakes of Saturn’s moon Titan may explain the lakes’ stillness, and could influence the atmospheric hydrocarbon cycle.

Pyroclastic density currents generate a basal air cushion that reduces friction with the ground, reveal laboratory experiments. This explains their ability to travel rapidly over large distances from their volcanic source.

Organic aerosols that sediment from Titan’s atmosphere may float, form a film and damp waves on Titan’s seas, according to computations. This damping effect could explain the observed smoothness of Titan’s seas.

The seasonal cycle in the methane mixing ratio observed at Gale Crater on Mars can be explained by adsorption onto and diffusion through the regolith, suggests a one-dimensional numerical model with geological constraints.

A methane spike 15.5 ± 2.5 parts per billion by volume was detected in the Martian atmosphere above Gale Crater on 16 June 2013 by Mars Express, independently confirming the debated in situ observation by the Curiosity rover a day earlier.

Water is uniformly present at low concentrations in the Moon’s subsoil and is emitted by meteoroid impacts, according to analysis of water releases detected by NASA’s Lunar Atmosphere and Dust Environment Explorer.

Microplastics can reach and affect regions far from where they are released because of atmospheric transport, suggest analyses of atmospheric deposition in a remote, pristine mountain catchment in France.

Terrestrial and planetary subaqueous and aeolian ripples and dunes can be compared in a unified framework, according to simulations with a hydrodynamic and sediment transport model.

Effective heat transport in the global ocean is dominated by heat export from the tropical Pacific, whereas seawater transport pathways play only a minor role, according to an analysis of a gridded ocean data product.

Deep Atlantic carbon storage increased and the meriodional overturning circulation weakened at the mid-Pleistocene transition to 100,000-year glacial–interglacial cycles, according to analyses of foraminifera trace elements and Nd isotopes.

Eleven phases of advance of the Greenland Ice Sheet, following the first expansion between 3.3 and 2.6 million years ago, are documented in analyses of a grid of seismic reflection data.

Long-period Milankovitch eccentricity oscillations controlled compositional variations in the 2.48-billion-year-old Kuruman Banded Iron Formation, according to cyclostratigraphic analysis and high-precision dating.

In the Proterozoic, sulfate concentrations in the oceans were low and atmospheric methane levels high, according to mass balance and diagenetic models that investigate the oxidation state of the Proterozoic oceans.

Pyroclastic density currents are able to travel large distances because they generate their own air lubrication, according to large-scale laboratory experiments.

After a fault ruptures, the recovery of its strength may be accelerated by earthquakes that redistribute stress, according to an analysis of temporal variation in crustal seismic velocity on the Longmenshan fault in China.

Geomagnetic jerks in the Earth’s magnetic field are caused by the arrival of hydromagnetic waves and could be generated by sudden releases of buoyancy in the Earth’s core, suggest geodynamic numerical model simulations.