Volume 15 Issue 6, June 2022

The surface of the asteroid Bennu is so weakly bonded that rockslide avalanches are easily triggered by small body impacts, and boulders fractured due to diurnal heating and cooling are readily dislodged. The result is a surface under continuous renewal.

This study shows that by stabilizing the soil, biological soil crusts reduce global atmospheric dust emissions by 60%, corresponding to ~700 Tg of dust per year. According to models of biocrust cover loss, this effect will be reduced in the future, leading to increases in not only dust emissions but also global radiative cooling.

Preferential P retention emerges in almost 90% of global lakes. This retention leads to a strong elevation in the N:P ratios in lakes outflow, exacerbates the imbalance of the nutrient cycles and can potentially result in biodiversity losses and algal blooms in lakes and downstream ecosystems.

In a simulation with a state-of-the-art climate model, obstruction of the ocean gateways in the Canadian archipelago due to ice-sheet growth reroutes currents and alters North Atlantic Ocean conditions, permitting glacial inception in Scandinavia. This mechanism could help to explain periods of rapid ice-sheet growth in Earth’s history.

Megathrust aftershocks can be highly destructive if they strike close to shore. Here, we show that aftershocks on the rupture surface have an initially high rate but shut down within several years, potentially for centuries. However, aftershocks also surround the rupture, where they persist for up to 60 years.

Boulder armouring inhibits small-crater formation on the rubble-pile asteroid Bennu, substantially reducing surface age estimates, according to an analysis of the crater size–frequency distribution.

Observations of deposits associated with a crater on the rubble-pile asteroid Bennu indicate a surface with low strength that is readily reworked by impact processes.

Fractures on the asteroid Bennu imaged by the OSIRIS-REx spacecraft are consistent with cracking induced by diurnal temperature variations over geologically rapid timescales.

Biocrusts reduce global atmospheric dust emission by 60%, and future biocrust losses due to climate and land-use changes will exacerbate this effect, according to global models of dust cycling.

Lakes preferentially retain phosphorous over nitrogen, amplifying the imbalance of nutrient cycles caused by anthropogenic inputs, according to analyses of more than 5,000 lakes globally.

Tropical Pacific islands enhance phytoplankton biomass, productivity and biodiversity at both local and basin scales, according to ocean colour satellite observations used to identify island-enriched waters.

Temperature observations from across Alaska show widespread talik formation in the discontinuous permafrost zone due to higher air temperatures and above-average snowfall in recent years.

Infilling of Canadian Arctic ocean gateways by the Laurentide Ice Sheet probably triggered Scandinavian glaciation during the last glacial inception by increasing North Atlantic freshwater inputs, according to coupled ice-sheet–climate-model simulations.

The ocean during Neoproterozoic Snowball Earth episodes did not have an ice-free belt in the tropics when likely cloud conditions are taken into account, according to climate and energy-balance modelling.

Seismicity close to the rupture surface can shut down for centuries following a megathrust earthquake, while a much larger area surrounding it is activated for decades, according to numerical modelling of the 2011 Tohoku and other megathrust earthquakes.

The water content of arc magmas in the lower crust can reach up to 20 wt% during crystallization, according to geochemical analyses of minerals from the Kohistan palaeo-arc, Pakistan, underscoring the role of water in porphyry deposits formation.